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Bio test 4 Aug. 2009
Last Bio Exam Summer 2009
| Question | Answer |
|---|---|
| The nervous system functions to: | 1. Respond rapidly to changes in the environment 2. Coordinate Blood activities 3. Store Knowledge |
| Neuron | Communication cell in the nervous system |
| Axon terminal | (synaptic terminal) located at the end of the axon. Neurotransmitters (chemical messengers) are released to signal target cells (neurons, muscles, or glands) |
| Synapse | junction between an axon and another cell |
| Synaptic terminal | passes info accross the synapse in the form of chemical messengers |
| Dendrites | highly branched signals |
| Cell Body | contain most of a neuron's organelles |
| Axon Hillock | joins the cell body to the axon. Area where electrical signals are created. |
| Axon | much longer extension than dendrites. Rapidly transmits signals (action potentials) to other cells at synapses. |
| Information travels from a... | Presynaptic cell (neuron) to a postsynaptic cell (neuron, muscle or gland cell) |
| Glia | glial cells. Cells that nourish or insulate neurons |
| Myelin Sheath | form of insulation by glial cells. |
| Membrane Potential | Voltage (difference in electrical charge) across its plasma membrane |
| Resting potential | the membrane potential of a neuron not sending signals |
| K and Na concentrations in a mammalian neuron at resting potential. | K is greater inside the cell, while Na is greater outside the cell |
| Chemical potential energy | represented by concentration gradients |
| ion channels | opening of ion channels in the plasma membrane converts chemical energy to electrical potential energy |
| At resting potential a neuron contains many open ... channels and fewer open ... channels. ... diffuses out of the cell. | K; Na; K |
| Anions trapped inside the cell contribute to the ... charge within the neuron | negative |
| Gated ion channels | open or close in response to stimuli. Membrane potentials change in response to opening or closing of these channels |
| When gated K+ channels open,... | K+ diffuses out making the inside of the cell more negative |
| Hyperpolarization | increase in magnitude of the membrane potential |
| Depolarization | reduction in the magnitude of the membrane potential. Occurs when Na+ channels open and Na+ diffuses into the cell |
| Graded potentials | changes in polarization where the magnitude of the change varies with the strength of the stimulus |
| Action potential | a strong stimulus results in a massive change in membrane voltage |
| Neuron can produce... of action potentials per second | hundreds |
| The ... of action potentials can reflect the strength of stimulus | frequency |
| An action potential occurs if a stimulus causes the membrane voltage to cross a particular ... | threshold |
| Action potential is a brief... depolarization of a neurons plasma membrane | all or none |
| At resting potential | most voltage gated Na+ and K+ channels are closed, but some K+ channels (not voltage gated) are open |
| When an action potential is generated | - Voltage gated Na+ channels open and Na+ flows in - Rising Phase: threshold is crossed and membrane potential increases -Falling Phase: voltage Na+ channels close; K+ channels open; K flows out -Undershoot(hyperpolarization): K channels close; <resti |
| At the site where the action potential is generated, usually the..., an electrical current... the neighboring region of the axon membrane | axon hillock; depolarizes. |
| Action potentials travel | toward the synaptic terminals (one direction) |
| Speed of action potential increases with axons... | diameter |
| In vertebrates, axons are inulated by ... which cause.. | myelin sheath; an action potential speed to increase |
| Action potentials jump between... in a process called... | nodes of Ranvier; Saltatory conduction |
| Myelin sheaths are made by glia | Oligodendrocytes in the CNS; Schwann cells in the PNS |
| At electrical synapses,... | -the electrical current flows from one neuron to another. Synapses formed by gap junctions -ie. Cardiac muscle cells |
| Chemical synapses | a chemical neurotransmitter carries info across the synaptic cleft. Most synapses are chemical synapses |
| presynaptic neuron | synthesizes and packages the neurotransmitter in synaptic vesicles located in the synaptic terminal |
| Nuerotransmitter diffuses across the... and is received by the postsynaptic cell | synaptic cleft |
| Postsynaptic potential | neurotransmitter binding causes ion channels to open |
| If enough postsynaptic potentials depolarize the postsynaptic neuron to .... an action potential will be formed | threshold |
| the same neurotransmitter can produce | different effects in different types of cells |
| There are 5 major classes of neurotransmitters: | 1. Acetylcholine 2. Biogenic Amines 3. Amino Acids 4. Neuropeptides 5. Gases |
| Sensors detect external stimuli and internal conditions and transmit information along... | sensory neurons |
| Sensory information is sent to the brain where ... integrate the information. ...also connect sensory and motor neurons | Interneurons |
| Motor output leaves the brain via ..., which trigger muscle or gland activity | motor neurons |
| central nervous system (CNS) | where integration takes place; this includes the brain and spinal cord |
| peripheral nervous system (PNS) | which brings information into and out of the CNS. It consists of nerves that connect the CNS with body tissues. A nerve is a collection of axons in a bundle |
| The PNS is composed of 2 divisions: | 1. Somatic division – consists of nerves that connect to skeletal muscles. •Voluntary control 2. Autonomic division – consists of nerves that connect to internal body organs. –Involuntary control |
| Major brain areas include: | 1.Forebrain 2.Midbrain 3.Hindbrain |
| Forebrain – consists of: | •Cerebral cortex – functions include complex brain activity (personality, hearing, vision, sensations, movement, speech) •Hypothalamus – controls pituitary hormone secretions, regulates thirst, hunger, etc. |
| Midbrain – consists of: | •Midbrain (superior part of brain stem) – receives and integrates sensory info |
| Hindbrain – consists of: | •Pons and medulla – controls internal body functions, heart beat, breathing, etc. •Cerebellum – coordinates muscle movement |
| Sensation involves | converting energy into a change in the membrane potential of sensory receptors |
| Sensations are | action potentials that reach the brain via sensory neurons |
| Functions of sensory pathways: | sensory reception, transduction, transmission, and integration. |
| Sensations and perceptions begin with ..., detection of stimuli by sensory receptors | sensory reception |
| Sensory receptors can | detect stimuli outside and inside the body |
| Sensory transduction is | the conversion of stimulus energy into a change in the membrane potential of a sensory receptor |
| This change in membrane potential is called | a receptor potential |
| Based on energy transduced, sensory receptors fall into five categories: | 1.Mechanoreceptors 2.Chemoreceptors 3.Electromagnetic receptors 4.Thermoreceptors 5.Pain receptors |
| Mechanoreceptors | sense physical deformation caused by stimuli such as pressure, stretch, motion, and sound. The sense of touch in mammals relies on mechanoreceptors that are dendrites of sensory neurons |
| chemoreceptors | transmit information about the total solute concentration of a solution. Provides a sense of smell and taste |
| Electromagnetic receptors | detect electromagnetic energy such as light, electricity, and magnetism |
| Thermoreceptors | respond to heat or cold, help regulate body temperature by signaling both surface and body core temperature |
| In humans, pain receptors, or nociceptors,.. | are a class of naked dendrites in the epidermis. They respond to excess heat, pressure, or chemicals released from damaged or inflamed tissues |
| A single sensory receptor cell detects the sensory stimulus and, through its axon, sends action potentials to the CNS | Occurs in olfactory, pain, touch, pressure, and body position receptors |
| A specialized sensory receptor cell detects the stimulus. It lacks an axon so it synapses with a sensory neuron (which has an axon) to transmit action potentials to the CNS. | Occurs in sound, light, and taste receptors |
| Muscle activity is a response to input from the... | nervous system |
| Motor output occurs through motor neurons that are connected to: | 1. Skeletal muscles 2. Smooth muscles 3. Cardiac muscles of the heart 4. Gland cells |
| The action of a muscle is always to... | contract |
| During contraction, the muscle cell... | shortens |
| A muscle cannot push, it always... | pulls (contracts) |
| Vertebrate skeletal muscle is characterized by... | a hierarchy of smaller and smaller units |
| A skeletal muscle consists of: | a bundle of long fibers, each a single cell, running parallel to the length of the muscle |
| Each muscle fiber is itself a bundle of: | smaller myofibrils arranged longitudinally |
| The myofibrils are composed of two kinds of myofilaments: | 1. Thin filaments: consist of two strands of actin and one strand of regulatory protein 2. Thick filaments: staggered arrays of myosin molecules |
| Skeletal muscle is also called... | striated muscle because the regular arrangement of myofilaments creates a pattern of light and dark bands. |
| The functional unit of a muscle is called a... | sarcomere and is bordered by Z lines |
| Thin filaments anchored to the ends of the sarcomere at the | Z line |
| Thick filaments anchored in sarcomere at | M line |
| According to the sliding-filament model, | filaments slide past each other longitudinally, producing more overlap between thin and thick filaments |
| The sliding of filaments is based on interaction between: | actin of the thin filaments and myosin of the thick filaments |
| The "head" of a myosin molecule binds... | an actin filament, forming a cross bridge and pulling the thin filament toward the center of the sarcomere |
| Glycolysis and aerobic respiration... | generate the ATP needed to sustain muscle contraction |
| A skeletal muscle fiber contracts only when... | stimulated by a motor neuron |
| When a muscle is at rest, myosin binding sites on the thin filament are blocked by the regulatory protein... | tropomyosin |
| For a muscle fiber to contract, | myosin binding sites must be uncovered; Occurs when calcium ions (Ca2+) bind to a set of regulatory proteins, the troponin complex |
| Muscle fiber contracts when... | the concentration of Ca 2+ is high |
| Muscle fiber contraction stops when... | the concentration of Ca2+ is low |
| How does calcium enter the muscle cell? | Motor neuron sends an action potential to the muscle cell. The muscle cell then forms an action potential which causes release of Ca2+ from the sarcoplasmic reticulum. Ca binds to the thin filaments in sarcomere to allow sliding b/t thin&thick filaments |
| Amyotrophic lateral sclerosis (ALS), formerly called Lou Gehrig's disease, interferes with the... | excitation of skeletal muscle fibers; this disease is usually fatal |
| Myasthenia gravis is an... | autoimmune disease that attacks acetylcholine receptors on muscle fibers; treatments exist for this disease |
| Contraction of a whole muscle is graded, which means... | the extent and strength of its contraction can be voluntarily altered |
| There are two basic mechanisms by which the nervous system produces graded contractions: | 1. Varying the number of fibers that contract 2. Varying the rate at which fibers are stimulated |
| In a vertebrate skeletal muscle, each branched muscle fiber is innervated by how many motor neurons | 1 |
| Each motor neuron may synapse with... muscle fibers | multiple |
| A motor unit consists of a ... motor neuron and all the ... it controls | single; muscle fibers |
| Recruitment of multiple motor neurons results in ... | stronger contractions |
| A twitch results from ... | a single action potential in a motor neuron |
| More rapidly delivered action potentials produce a graded contraction by ... | summation |
| ... is a state of smooth and sustained contraction produced when motor neurons deliver a volley of action potentials | Tetanus |
| Skeletal muscle fibers can be classified: | 1. As oxidative or glycolytic fibers, by the source of ATP 2. As fast-twitch or slow twitch fibers, by the speed of muscle contraction |
| Oxidative fibers | rely on aerobic respiration to generate ATP; These fibers have many mitochondria, a rich blood supply, and much myoglobin. Myoglobin is a protein that binds oxygen more tightly than hemoglobin. |
| Myoglobin | a protein that binds oxygen more tightly than hemoglobin |
| Glycolytic fibers | use glycolysis as their primary source of ATP. Glycolytic fibers have less Myoglobin than oxidative fibers, and tire more easily. In poultry and fish, light meat is composed of glycolytic fibers, while dark meat is composed of oxidative fibers |
| Slow twitch fibers | contract more slowly, but sustain longer contractions. All slow twitch fibers are oxidative. |
| Fast twitch fibers | contract more rapidly, but sustain shorter contractions. Fast twitch fibers can be either glycolytic or oxidative |
| Most skeletal muscles contain both ... and ... muscles in varying ratios | slow twitch; fast twitch |
| In addition to skeletal muscles, vertebrates have ... | cardiac muscle and smooth muscle |
| Cardiac muscle, found only in the..., consists of ... cells electrically connected by intercalated disks | heart; striated. Gap junctions connect cells together |
| Cardiac muscles can generate action potentials without... | neural input. Produced by pacemaker cells. |
| In..., found mainly in walls of hollow organs, contractions are relatively slow and may be initiated by the muscles themselves | smooth muscle. -Thick filament scattered throughout cytoplasm, thin filaments attached to plasma membrane (not striated in appearance) |
| Contractions may also be caused by .... in the autonomic nervous system | stimulation from neurons |
| ... are chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body | Animal hormones |
| ... reach all parts of the body, but only target cells are equipped to respond | Hormones. -Insect metamorphosis is regulated by hormones |
| Two systems coordinate communication throughout the body: | the endocrine system and the nervous system |
| Endocrine system | secretes hormones that coordinate slower but longer-acting responses including reproduction, development, energy metabolism, growth, and behavior |
| Nervous system | conveys high speed electrical signals along specialized cells called neurons; these signals regulate other cells |
| ... bind to receptor proteins on target cells | Chemical signals. Only target cells containing the receptors can respond to the signal |
| Secreted chemical signals include: | 1. Hormones 2. Local regulators 3. Neurotransmitters 4. Neurohormones 5. Pheromones |
| Endocrine signals (hormones) | are secreted into extracellular fluids and travel via the bloodstream |
| Endocrine glands | ductless and secrete hormones directly into surrounding fluid |
| ... mediate responses to environmental stimuli and regulate growth, development, and reproduction | Hormones. The target cells need the receptor for the hormone to have an effect |
| Exocrine glands | have ducts and secrete substances onto body surfaces or into body cavities. For example: tear ducts. |
| Local regulators | chemical signals that travel over short distances by diffusion. Help regulate blood pressure, nervous system function, and reproduction |
| Local regulators are divided into two types | 1. Pacrine 2. Autocrine |
| Pacrine | signals act on cells near the secreting cell |
| Autocrine | signals act on the secreting cell itself |
| Neurons (nerve cells) contact target cells at... | contact target cells at synapses |
| At synapses, neurons often secrete chemical signals called... | neurotransmitters that diffuse a short distance to bind to receptors on the target cell. |
| Neurotransmitters play a role in | sensation, memory, cognition, and movement |
| Neurohormones | a class of hormones that originate from neurons in the brain and diffuse through the bloodstream |
| Pheromones | chemical signals that are released from the body and used to communicate with other individuals in the species. Mark trails to food sources, warning of predators, defining territories and attract potential mates. |
| Three major classes of molecules function as hormones in vertebrates: | 1. Polypeptides (proteins and peptides) 2. Amines derived from amino acids 3. Steroid hormones |
| Lipid soluble hormones (steroid hormones) pass easily through ..., while water soluble hormone (polypetides and amines) do not | cell membranes; -The solubility of a hormone correlates with the location of receptors inside or on the surface of target cells |
| Water and lipid soluble hormones differ in their ... through a body | paths |
| ... hormones are secreted by exocytosis, travel freely in the bloodstream, and bind to cell surface receptors | Water-soluble |
| ... hormones diffuse accross cell membranes, travel in the bloodstream bound to transport proteins, and diffuse through the membrane of target cells | Lipid-soluble |
| Signaling by any of these hormones involves three key events: | 1. Reception 2. Signal transduction 3. Response |
| Binding of a hormone to its receptor initiates a... pathway leading to responses in the cytoplasm, enzyme activation, or a change in gene expression | signal transduction |
| The hormone ... has multiple effects in mediating the body's response to short term stress | epinephrine |
| Epinephrine binds to ... on the plasma membrane of ... cells | receptors; liver |
| This triggers the release of ... molecules that activate enzymes and result in the release of glucose into the bloodstream | messenger |
| The response to a ... hormone is usually a change in gene expression | lipid-soluble |
| Steroids, thyroid hormones, and the hormonal form of vitamin D enter target cells and bind to ... in the cytoplasm or nucleus | protein receptors |
| Protein-receptor complexes then act as ... in the nucleus, regulating transcription of specific genes | transcription factors |
| The same hormone may have different effects on target cells that have | -different receptors for the hormone -different signal transduction pathways -different proteins for carrying out the response |
| A hormone can also have ... effects in different species | different |
| ... are released from an endocrine cell, travel through the bloodstream, and interact with the receptor or a target cell to cause a physiological response | Hormones |
| A ... loop inhibits a response by reducing the initial stimulus | negative feedback. |
| Negative feedback regulates many hormonal pathways involved in ... | homeostasis |
| The ... has clusters of endocrine cells called islets of Langerhans with alpha cells that produce glucagon and beta cells that produce insulin | pancreas |
| Insulin reduces blood glucose levels by: | 1. Promoting the cellular uptake of glucose 2. Slowing glycogen breakdown in the liver 3. Promoting fat storage |
| Glucagon increases blood glucose levels by: | -Stimulating conversion of glycogen in the liver -Stimulating breakdown of fat and protein into glucose |
| ... is the best known endocrine disorder. It is caused by a deficiency of insulin or a decreased response to insulin in target tissues. It is marked by elevated blood glucose levels | Diabetes mellitus |
| Type I diabeter mellitus | (insulin dependent) is an autoimmune disorder in which the immune system destroys pancreatic beta cells |
| Type II diabetes mellitus | (non-insulin dependent) involves insulin deficiency or reduced response of target cells due to change in insulin receptors. "Adult onset" generally appears after age 40 or may appear in overweight children. |
| Signals from the ... initiate and regulate endocrine signals | nervous system |
| The ... receives information from the nervous system and initiates responses through the endocrine system | hypothalamus |
| Attached to the hypothalamus is the ... composed of the ... and ... | pituitary gland; posterior pituitary; anterior pituitary |
| Posterior pituitary | stores and secretes hormones that are made in the hypothalamus |
| Anterior pituitary | makes and releases hormones under regulation of the hypothalamus |
| The two hormones released from the posterior pituitary act directly on ... tissues | nonendocrine. -the two hormones released are oxytocin and antidiuretic hormone (ADH) |
| Antidiuretic hormone | enhances water reabsorption in the kidneys |
| Hormone production in the anterior pituitary is controlled by .... | releasing and inhibiting hormones from the hypothalamus |
| Anterior pituitary hormones include: | 1. Follicle stimulating hormone 2. Luteinizing hormone 3. Thyroid stimulating hormone 4. Andrenocorticotropic hormone 5. Prolactin 6. Growth hormone |
| The pituitary releases both ... and ... hormones | tropic and nontropic |
| A ... hormone regulates the function of endocrine cells or glands | tropic |
| A ... hormone does not regulate the function of endocrine cells or glands | nontropic |
| A hormone can stimulate the release of a series of other hormone, the last of which activates a nonendocrine target cell; this is called a ... | hormone cascade pathway. -Hormone cascade pathways are usually regulated by negative feedback |
| The release of a thyroid hormone results from a ... involving the hypothalamus, anterior pituitary, and thyroid gland | hormone cascade pathway |
| ... is secreted by the anterior pituitary gland and has both tropic and nontropic actions | Growth hormone. -It promotes growth directly and has diverse metabolic effects. It stimulates production of growth factors. An excess of GH can cause gigantism, while a lack of GH can cause dwarfism |
| The ... consists of two lobes on the ventral surface of the trachea | thyroid gland. -It produces two iodine containing hormones: triiodothyronine(T3) and thyroxine (T4) |
| Thyroid hormones stimulate... | metabolism and influence development and maturation |
| Hyperthyroidism | excessive secretion of thyroid hormones, causes high body temperature, weight loss, irritability, and high blood pressure |
| Hypothyroidism | low secretion of thyroid hormones, causes weight gain, lethargy, and intolerance to cold |
| Proper thyroid function requires dietary ... for hormone production | iodine. -lack of iodine can cause goiter formation |
| The adrenal glands are adjacent to the... | kidneys |
| Each adrenal gland consists of two glands: | the adrenal medulla (inner portion) and adrenal cortex (outer portion) |
| The adrenal medulla secretes ... and ... | epinephrine (adrenaline) and norepinephrine (noradrenaline). -They are secreted in response to stress activated impulses from the nervous system. They mediate various fight or flight response. |
| Epinephrine and norepinephrine can: | -Trigger the release of glucose and fatty acids into the blood. Increase oxygen delivery to body cells. Direct blood toward heart, brain, and skeletal muscles, and away from skin, digestive systems and kidneys. |
| The release of epinephrine and norepinephrine occurs in response to nerve signals from ... | the hypothalamus |
| ... supplies oxygen for cellular respiration and disposes of carbon dioxide | Gas exchange; Delivers O2 to tissues and removes CO2 from tissues |
| Gases diffuse down pressure gradients in the lungs and other organs as a result of differences in ... | partial pressure |
| ... is the pressure exerted by a particular gas in a mixture of gases | Partial pressure |
| A gas diffuses from a region of ... partial pressure to a region of ... partial pressure | higher; lower |
| In the lungs and tissues, O2 and CO2 diffuse from where their partial pressures are ... to where they are ... | higher; lower |
| Obtaining O2 from water requires greater ... than air breathing | efficiency |
| Gas exchange accross respiratory surfaces takes place by ... | diffusion |
| ... surfaces vary by animal and can include the outer surface, skin, gills, and tracheae, and lungs | Respiratory |
| Gills | outfoldings of the body that create a large surface area for gas exchange. Capillaries in gills take up O2 by diffusion from H2O to cappillary blood. |
| Ventillation | moves the respiratory medium over the respiratory surface |
| Countercurrent exchange system | Used by fish gills where blood flows in the opposite direction to water passing over the gills; Blood is always less saturated with O2 than the water it meets. This increases uptake of O2 |
| Tracheal system | insects consists of tiny branching tubes that penetrate the body |
| Traceae connected to body surface through openings called ... | spinacles |
| ... are infolding of the body surface | Lungs |
| The size and complexity of lungs correlate with an animal's ... rate | metabolic |
| Air inhaled through the nostrils passes through the ... via the larynx, trachea, bronchi, bronchioles, and alveoli, where gas exchange occurs | pharynx |
| Exhaled air passes over the ... to create sounds | vocal cords |
| Secretions called ... coat the surface of the alveoli | surfactants |
| Alveoli | (sac like endings on bronchioles) site of O2/CO2 exchange |
| Mammals ventilate their lungs by ... which pulls air into the lungs | negative pressure breathing |
| Tidal volume | volume of air inhaled with each breath |
| Vital capacity | maximum tidal volume |
| Residual volume | after exhalation, the volume of air that remains in the lungs |
| Blood arriving in the lungs has a ... partial pressure of O2 and a ... partial pressure of CO2 relative to air in the alveoli | low; high |
| In the alveoli, ... diffuses into the blood (from the lungs) and ... (from the blood) diffuses into the air | O2; CO2 |
| In tissue capillaries, | partial pressure gradients favor diffusion of O2 into the interstitial fluids and CO2 into the blood (opposite of what happens in the lungs) |
| Respiratory pigments | proteins that transport oxygen, greatly increase the amount of oxygen that blood can carry |
| Most vertebrates and some invertebrates use ... contained within erythrocytes to bind/transport O2 | hemoglobin |
| A single hemoglobin molecule can carry ... molecules of O2 | four |
| Bohr shift | CO2 produced during cellular respiration lowers blood pH and decreases the affinity of hemoglobin for O2 |
| CO2 from respiring cells diffuses into the blood and is transported either in ....,...., or as .... | blood plasma, bound to hemoglobin, or a bicarbonate ions (HCO3-) |
| Blood carries CO2 in all forms to the... | lung capillaries |
| In the lungs, HCO3- is converted back to ... | CO2 |
| CO2 diffuses from the lung capillaries into the... | alveolar air |
| Every organism must exchange materials with its environment. Exchanges ultimately occur at the ... level | cellular |
| In unicellular organisms, these exchanges occur directly with the ... | environment |
| For most cells making up multicellular organisms, direct exchange with the environment is ... | not possible |
| ... are an example of a specialized exchange system in animals | Gills |
| Most complex animals have ... that circulate fluid | internal transport systems |
| Circulatory system function. TRANSPORT | nutrients, gases(CO2, O2), waste |
| Circulatory system function COMMUNICATION | through transport of hormones |
| Circulatory system function FIGHT INFECTIONS | through transport of white blood cells and antibody proteins |
| Circulatory system function CONTROL OF BODY TEMPERATURE | through the transport of heat |
| Circulatory system function CONTROL BODY pH | through transport of buffers |
| Complex animals have either ... or ... circulatory systems | open; closed |
| Both open or closed systems have three basic components | 1. A circulatory fluid (blood or hemolymph) 2. A set of tubes (blood vessels) 3. A muscular pump (the heart) |
| Open circulatory system | In insects, other arthropods, and most molluscs, the area where blood bathes the organs |
| Hemolymph | In a open circulatory system, a general body fluid; (there is no distinction between blood and interstitial fluid) |
| Closed circulatory system | blood is confined to vessels and is distinct from the interstitial fluid. Found in annelids, cephalopods, vertebrates such as fish, amphibians, reptiles, birds, and mammals. Closed systems are more efficient at transporting circulatory fluids. |
| Cardiovascular system | A closed circulatory system in humans and other vertebrates. |
| The three main types of blood vessels are: | arteries, veins, and capillaries |
| Arteries | branch into arterioles and carry blood to capillaries |
| Capillary beds | networks of capillaries that are the sites of chemical exchange between the blood and interstitial fluid |
| Venules | converge into veins and return blood from capillaries to the heart |
| Vertebrate hearts contain ... chambers | two or more |
| Blood enters through an atrium and is pumped out through a ... | ventricle |
| double circulation | Found in amphibian, reptiles, and mammals. Oxygen-poor and oxygen-rich blood are pumped separately from the right and left sides of the heart. |
| In reptiles and mammals, oxygen-poor blood flows through the ... to pick up oxygen through the lungs | pulmonary circuit |
| Oxygen-rich blood delivers oxygen through the ... | systemic circuit |
| Mammals have a four-chambered heart with... | 2 atria and 2 ventricles |
| The left side of the heart pumps and receives only oxygen rich blood, while ... | the right side receives and pumps only oxygen poor blood |
| Mammals are ... | endotherms and require more O2 than ectotherms |
| The mammalian cardiovascular system meets the body's continuous demand for ... | O2 |
| Blood begins its flow with the ... | right ventricle pumping blood to the lungs |
| In the lungs, the blood loads O2 and unloads ... | CO2 |
| Oxygen rich blood from the lungs enters the heart at the left atrium and is pumped through ... | the aorta (largest artery in the body) to the body tissues by the left ventricle |
| The aorta provides blood to the heart through the ... | coronary arteries |
| Blood returns to the heart through the ... | superior vena cava (blood from head, neck, and forelimbs) and inferior vena cava (blood from the trunk and hind limbs) |
| The super vena cava and inferior vena cava flow into the ... atrium | right |
| Backflow of blood prevented by ... valves | one-way |
| Atrioventricular valves | located between each atrium and ventricle |
| Pulmonary semilunar valve | located between the pulmonary trunk and right ventricle |
| Aortic semilunar vale | located between the aorta and left ventricle |
| The heart contracts and relaxes in a rhythmic cycle called the ... | cardiac cycle |
| Systole | the contraction, or pumping, phase |
| Diastole | the relaxation, or filling, phase |
| The heart rate | also called the pulse, is the number of beats per minute |
| The stroke volume | the amount of blood pumped in a single contraction |
| Cardiac output | the volume of blood pumped into the systemic circulation per minute and depends on both the heart rate and stroke volume. |
| Some cardiac muscle cells are self-excitable, meaning... | they contract without any signal from the nervous system |
| Sinoatrial (SA) node | or pacemaker, sets the rate and timing at which cardiac muscle cells contract |
| Atrioventricular (AV) node | receive impulses from the Sinoatrial (SA) node. At the AV node, the impulses are delayed and then travel to the Purkinje fibers that make the ventricles contract |
| Electrocardiogram (ECG or EKG) | Impulses that travel during the cardiac cycle can be recorded as (ECG or EKG) Electrocardiogram |
| The pacemaker | is influenced by nerves, hormones, body temperature, and exercise |
| Endothelium | the epithelial layer that lines blood vessels |
| Arteries composed of: | -Endothelium (inner layer-contacts blood) -Smooth muscle (middle layer) - Connective tissue (outer layer) |
| Arteries | have thicker walls than veins to accommodate the high pressure of blood pumped from the heart |
| Systolic pressure | the pressure in the arteries during ventricular systole; it is the highest pressure in the arteries |
| Diastolic pressure | the pressure in the arteries during diastole; it is lower than systolic pressure |
| Pulse | the rythmic bulging of artery walls with each heartbeat |
| Arteries | branch into smaller arterioles |
| Arterioles connect to a ... | capillary bed |
| Capillaries are the ... | smallest of the blood vessels |
| O2 and nutrients go from ... | blood to tissue |
| CO2 and organic waste (urea) goes from | tissue to blood |
| Blood leaving the capillaries enter ... | venules (small veins) |
| Venules converge into | veins |
| Veins are characterized by | Thinner walls than arteries (veins are composed of endothelium, smooth muscle and connective tissue) Contain one way valves, helps keep blood moving to heart. Move through veins by smooth+skeletal muscle contraction, & expansion of vena cava w/ inhalation |
| Velocity of blood flow is: | fastest in arteries (large diameter=low resistance). Slowest in the capillary beds as a result of high resistance and large total cross sectional area. Blood flow in capillaries is slow for exchange of materials |
| Exchange of nutrients or wastes occur in capillaries since: | -Capillaries have small diameters (slows down blood flow) -Capillaries have thin, porous walls (one cell thick) -Capillaries are numerous. Exchange is by diffusion and bulk transport across cells of the capillary wall and through pores between cells |
| Some net loss of blood fluid from tissues to capillaries (fluid movement from capillary to tissue > fluid movement from tissue to capillary). Excess fluid in tissue accumulates as ... | lymph |
| Blood pressure | is hydrostatic pressure that blood exerts against the wall of a vessel |
| In rigid vessels blood pressure is ... | maintained; less rigid vessels deform and blood pressure is lost |
| Vasoconstriction | the contraction of smooth muscle in arteriole walls; it increases blood pressure |
| Vasodilation | is the relaxation of smooth muscles in the arterioles; it causes blood pressure to fall |
| Vasoconstriction and vasodilation help maintain adequate... | blood flow as the body's demand change |
| Endothelin | an important inducer of vasoconstriction |
| Capillaries in major organs are usually filled to.. | capacity |
| Two mechanisms regulate distribution of blood in capillary beds: | -Contraction of the smooth muscle layer in the wall of an arteriole constricts the vessel -Precapillary sphincters control flow of blood between arterioles and venules |
| lymphatic system | returns fluid that leaks out in the capillary beds |
| Lymph | fluid that reenters the circulation directly at the venous end of the capillary bed and indirectly through the lymphatic system |
| lymphatic system drains into veins in the ... | neck |
| Lymph nodes | organs that filter lymph and play an important role in the body's defense |
| Edema | swelling caused by disruptions in the flow of lymph |
| In invertebrates with open circulation, blood (hemolymph) is not different from ... | interstitial fluid |
| Blood in the circulatory systems of vertebrates is a ... | specialized connective tissue |
| Plasma | a liquid matrix of blood which consists of several kinds of cells. 55% of blood is plasma (fluid). |
| The cellular elements occupy about ...% of the volume of blood | 45 |
| Blood contains: | -Gases -Nutrients -Hormones -Wastes -Proteins(including antibody proteins) -Buffers |
| Blood plasma is about ..% water | 90 |
| electrolytes | a solute of plasma, are inorganic salts in the form of dissolved ions |
| plasma proteins | an important class of solutes within plasma, which influence blood pH, osmotic pressure, and viscosity |
| Plasma proteins function in: | lipid transport, immunity, and blood clotting |
| Suspended in blood plasma are two types of cells: | 1. Red blood cells (erythrocytes)-contain hemoglobin to transport oxygen 2. White blood cells (leukocytes)- function in defense |
| Platelets | a third cellular element, are fragments of cells that are involved in clotting |
| Erythrocytes | Red blood cells; are by far the most numerous blood cells. They transport oxygen throughout the body. They contain hemoglobin, the iron containing protein that transports oxygen |
| Hemoglobin | the iron containing protein that transports oxygen |
| There are five major types of white blood cells, or leukocytes: | monocytes, neutrophils, basophils, eosinophils, and lymphocytes. They function in defense by phagocytizing bacteria and debris or by producing antibodies. They are found both in and outside of the circulatory system |
| Platelets | fragments of cells that function in blood clotting |
| When a endothelium of a blood vessel is damaged, the .... begins | clotting mechanism |
| Blood clotting | -Injured tissue and nearby platelets release clotting factors -Clotting factors convert prothrombin (plasma protein) into thrombin -Thrombin converts fibrinogen (plasma protein) to fibrin to form the clot |
| Pathogens | biological agents that cause disease or illness to its host |
| Barriers help an animal defend itself from the many dangerous .... it may encounter | pathogens |
| the immune system recognizes.... and responds with.... | foreign bodies.... the production of immune cells and proteins [defends against viruses, bacteria, protozoans, worms, toxic molecules] |
| two kinds of immunity | 1. innate 2. acquired |
| innate immunity | is present before and exposure to pathogens effective from birth nonspecific responses to pathogens |
| nonspecific responses involved in innate immunity are: | external barriers (skin, mucous membrane) internal cellular and chemical defenses (WBC, inflammatory response) |
| acquired immunity aka adaptive ammunity | develops after exposure to microbes/ toxins/ foreign substances involves a VERY SPECIFIC response to pathogens |
| specific responses to pathogens | antibodies, cytotoxic lymphocytes |
| both invertebrates and vertebrates depend on...... immunity to fight infection | innate |
| vertebrates also develop..... immune defenses | acquired |
| Innate defenses include: | barrier defenses, phagocytosis, antimicrobial peptides |
| Additional defenses are unique to vertebrates: | the inflammatory response and natural killer cells |
| Barrier defenses include: | the skin and mucous membranes of the respiratory, urinary, and reproductive tracts |
| Mucus | traps and allows for the removal of microbes |
| Many body fluids including saliva, mucus, and tears are... to microbes | hostile |
| The low pH of skin and the digestive system prevents growth of ... | microbes |
| White blood cells (leukocytes) engulf ... in the body | pathogens; Neutrophils and monocytes (macrophages) carry out phagocytosis of pathogens. A white blood cell engulfs a microbe, then the vesicle fuses with a lysosome to destroy the microbe. |
| Peptides and proteins function in innate defense by attacking microbes directly or impending their... | reproduction |
| Interferon proteins | provide innate defense against viruses and help activate macrophages |
| About 30 proteins make up the ... system, which causes lysis of invading cells and helps trigger inflammation | complement |
| Following an injury, mast cells and basophils release ...., which promotes changes in blood vessels (makes them more porous); this is part of the inflammatory response | histamine; These changes increase local blood supply and allow more phagocytes and antimicrobial proteins to enter tissues |
| Pus | a fluid rich in white blood cells, dead microbes, and cell debris, accumulates at the site of inflammation |
| Inflammation can be either local or .... | systemic (throughout the body) |
| Systemic inflammatory response | such as fever, which is triggered by pyrogens released by macrophages, and toxins from pathogens. Septic shock is a life threatening condition caused by an overwhelming inflammatory response. |
| All cells in the body (except red blood cells) have a ... MHC protein on their surface | Class I; Cancerous or virus infected cells no longer express the protein; Natural killer (NK) cells attack these damaged cells |
| Some pathogens avoid destruction by modifying their surface to prevent recognition or by resisting breakdown following phagocytosis. | Tuberculosis (TB) is one such disease and kills more than a million people a year. The bacterium can grow and reproduce into a host cell. |
| White blood cells called .... recognize and respond to antigens, foreign molecules | lymphocytes |
| Two types of lymphocytes | T cells and B cells |
| T cells | mature in the thymus above the heart. T lymphocytes have specific antibody molecules on their cell surface. |
| B cells | mature in bone marrow. Functions to secrete antibody proteins into the plasma (uses blood to circulate the infected tissues). Millions of different types of B lymphocytes exist, each secretes a specific antibody |
| Lymphocytes contribute to ..., an enhanced response to a foreign molecule encountered previously | immunological memory |
| Cytokines | secreted by macrophages and to recruit and activate lymphocytes |
| Antigen | any foreign molecule to which a lymphocyte responds |
| A single B cell or T cell has about 100,000 identical ... | antigen receptors. Each B or T cell recognizes a specific antigen. |
| All antigen receptors on a single lymphocyte recognize the same ..., or antigenic determinant, on an antigen | Epitope |
| When activated, B cells give rise to ..., which secrete proteins called antibodies or immunoglobulins | plasma cells |
| B cell receptors bind to ... | specific, intact antigens |
| The B cell receptor consists of ... | two identical heavy chains and two identical light chains |
| The tips of the chains form a constant (C) region, and each chain contains a variable (V) region, so named because its amino acid sequence varies from one B cell to another | The variable antigen is what binds to specific antigens |
| Secreted antibodies, or ...., are structurally similar to B cell receptors but lack transmembrane regions that anchor receptors in the plasma membrane | immunoglobulins |
| Binding of antibodies to antigen causes: | 1. Coating and neutralization of pathogen 2. Clumping and precipitation of pathogens 3. Activation of blood proteins (in the complement system) to bind and kill pathogen cells (1&2 make the target larger for phagocytosis by other white blood cells) |
| Each T cell receptor consists to two different polypeptide chains | The tips of the chain form a variable (V) region and the rest is a constant (C) region. T cells can bind to an antigen that is free or on the surface of a pathogen |
| The acquired immune system has three important properties: | 1. Receptor diversity 2. A lack of reactivity against host cells 3. Immunological memory |
| The first exposure to a specific antigen represents the ... | primary immune response. During this time, specific B cells recognize the antigens. The B cells divide into "memory B cells" and "plasma cells." Memory cells: remember the antigen. Plasma cells: release antibody molecules into the blood |
| Secondary immune response | memory B cells facilitate a faster, more efficient response. Memory B cells divide rapidly into plasma cells and produce antibodies rapidly (takes hours to days). Response produces more antibodies than primary response-less chance to get sick |
| Vaccinations introduce a disabled pathogen that contains the antigenic site. | This triggers the primary response but does not cause infection. Later when the person is introduced to the real pathogen, a secondary response occurs. Antibody production increases rapidly and in large amounts to prevent sickness |
| Acquired immunity has two brances: | the humoral immune response and the cell mediated response |
| Humoral immune response | involves activation and clonal selection of B cells, resulting in production of secreted antibodies |
| Cell mediated immune response | involves activation and clonal selection of cytotoxic T cells |
| T lymphocytes | have specific antibody molecules attached to their cell surfaces. T cells bind to and kill cell with specific antigens on their surfaces. These are are called cytotoxic T cells. Other T cells help regulate other lymphocytes (helper T cells) |
| Cytotoxic T cells | are the effector cells in cell mediated immune response. Binding to an infected cell activates a cytotoxic T cell and makes it a killer. The activated T cell secretes proteins that destroy the infected target cell. |
| The humoral response is characterized by secretion of ... cells | B; Activation of B cells is aided by cytokines and antigen binding to helper T cells. B cells divide, producing antibody-secreting plasma cells, the effector cells of humoral immunity |
| Many pathogens, antibodies, and white blood cells are filtered out at ... | lymph nodes; |
| Human immunodeficiency virus (HIV) infects .... cells | helper T; The loss of helper T cells impairs both the humoral and cell-mediated immune responses and lead to AIDS. HIV eludes the immune system because of antigenic variation and an ability to remain latent while integrated into host DNA |
| Food is taken in, taken apart, and taken up in the process of animal ... | nutrition |
| In general, animals fall into three categories | 1. Herbivores 2. Carnivores 3. Omnivores |
| Herbivores | eat mainly autotrophs (plants and algae) |
| Carnivores | eat other animals |
| Omnivores | regularly consume animals as well as plants or algal matter |
| An animals diet provides ... energy, which is converted into ATP and powers processes in the body | chemical |
| Animals need a source of ... in order to construct organic molecules | organic carbon and organic nitrogen |
| ... are required by cells and must be obtained from dietary sources | Essential nutrients |
| There are four classes of essential nutrients: | 1. Essential amino acids 2. Essential fatty acids 3. Vitamins 4. Minerals |
| Animals require 20 amino acids and can synthesize about ... from molecules in their diet | half |
| The remaining amino acids, the ... amino acids, must be obtained from food in preassembled form | essential |
| A diet that provides insufficient essential amino acids causes malnutrition called | protein deficiency |
| Meat, eggs, and cheese provide all the essential amino acids and are thus called .... proteins | complete |
| Most plant proteins are ... in amino acid makeup | incomplete |
| Individuals who only eat plant combinations need to eat specific plant combinations to get all ... | essential amino acids. |
| Some animals have ...that help them through periods when their bodies demand extraordinary amounts of protein | adaptations |
| The .... are certain unsaturated fatty acids that must be obtained from the diet | essential fatty acids |
| Vitamins are ... molecules required in the diet in small amounts | organic |
| 13 vitamins essential to humans have been identified: | Vitamin A required for vision. B vitamins act as coenzymes. Niacin for NAD+. Pantothenic acid for CoA. Vitamin D for bone formation. Vitamin K for blood clotting. |
| Vitamins are grouped into two categories: | 1. water soluble: B vitamins, vitamin C, biotin 2. fat soluble: vitamin A, D, E, K |
| ... are simple inorganic nutrients usually required in small amounts | Minerals; (calcium for bones and teeth, phosphorus for nucleotides, phospholipids, bones, iron for blood hemoglobin (O2 transport) |
| Undernourishment | the result of a diet that consistently supplies less chemical energy than the body requires |
| Malnourishment | the long term absence from the diet of one or more essential nutrients |
| An undernourished individual will: | Use up stored fate and carbohydrates. Break down its own proteins. Lose muscle mass. Suffer protein deficiency of the brain. Die or suffer irreversible damage. |
| Malnourishment can cause: | deformities, disease, and death. Malnourishment can be corrected by changes to a diet. |
| How do multicellular organisms obtain nutrients? | Through the digestive system: composed of specialized cells that: intake food, digest food substances, absorb nutrients, and eliminate waste products |
| Animal cells are organized into specific levels: | 1. Tissues-collection of cells with particular function. Ex. muscles in stomach wall 2. Organs-collection of tissues with particular functions. Ex. stomach 3. Organ systems-collection of organs with particular functions. ex. digestive system |
| ... is the act of eating | Ingestion |
| Many aquatic animals are ..., which sift small food particles from the water | suspension feeders |
| ... are animals that live in or on their food source | Substrate feeders |
| ... suck nutrient rich fluid from a living host | Fluid feeders |
| ... eat relatively large pieces of food | Bulk feeders |
| The main stages of food processing are ... | ingestion, digestion, absorption, and elimination. |
| ... is the process of breaking food down into molecules small enough to absorb | Digestion; In chemical digestion, the process of "enzymatic hydrolysis" splits bonds in molecules with the addition of water |
| ... is uptake of nutrients by body cells | Absorption |
| ... is the passage of undigested material out of the digestive compartment | Elimination |
| In ... digestion, food particles are engulfed by endocytosis and digested within food vacuoles | intracellular |
| ... is the breakdown of food particles outside of cells | Extracellular digestion; occurs in compartments that are continuous with the outside of the animal's body |
| Complex animals have a digestive tube with two openings: | a mouth and an anus. This digestive tube is called a complete digestive tract or an "alimentary canal." It can have specialized regions that carry out digestion and absorption in a stepwise fashion |
| Most animals process food in: | specialized compartments |
| The mammalian digestive system consists of an alimentary canal and accessory glands that secrete digestive juices through... | ducts |
| ... are the salivary glands, the pancrease, the liver, and the gallbladder | Mammalian accessory glands |
| Food is pushed along by ..., rhythmic contractions of muscles in the wall of the canal | peristalsis |
| Valves called ... regulate the movement of material between compartments | sphincters |
| The fat stage of digestion is mechanical and takes place in the ... | oral cavity |
| ... deliver saliva to lubricate food | Salivary glands |
| Teeth chew food into smaller particles that are exposed to salivary ..., initiating breakdown of glucose polymers | amylase; Digestion starts in the mouth with the break down of starch into maltose and glucose by amylase |
| The tongue shapes food into a ... and provides help with swallowing | bolus |
| The region we call our throat is the ... | pharynx, a junction that opens to both the esophagus and the trachea(windpipe). The esophagus conducts food from the pharynx down to the stomach by peristalsis. The trachea leads to the lungs. |
| Swallowing causes the epiglottis to block entry to the trachea, and the bolus is pushed into the esophagus and enters... | the stomach |
| The stomach stores food and secretes..., which converts a meal to acid ... | gastric juice; chyme |
| Gastric juice is made up of hydrochloric acid (HCl) and the enzyme... | pepsin; Parietal cell secrete hydrogen and chloride ions "seperately" |
| ... secrete inactive pepsinogen, which is activated to pepsin when mixed with hydrochloric acid in the stomach | Chief cells; Pepsin starts the digestion of proteins into amino acids. |
| ... protects the stomach lining from gastric juice | Mucus |
| Gastric ulcers, lesions in the lining, are caused mainly by the bacterium .... | Helicobacter pylori |
| ... prevent chyme from entering the esophagus and regulate its entry into the small intestine | Sphincters |
| The ... is the longest section of the alimentary canal | small intestine; It is the major organ of digestion and absorption. Digestion is completed in the small intestine. |
| The first portion of the small intestine is the ..., where acid chyme from the stomach mixes with digestive juices from the pancreas, liver, gallbladder, and the small intestine itself | duodenum |
| The pancreas produces pancreatic juice containing: | -Pancreatic amylase: completes starch digestion -Proteases trypsin and chymotrypsin: protein digesting enzymes that are activated after entering the duodenum. -Lipases: digest fats to glycerol and fatty acids -Nucleases: digest DNA and RNA to nucleotides |
| Pancreatic juice is alkaline and neutralizes the ... | acidic chyme |
| In the small intestine, ... aids in digestion and absorption of fats | bile |
| Bile is made in the .... and stored in the ... | liver; gallbladder; Bile breaks fats into small particles- emulsifies fats. This allows for lipases to work more efficiently. |
| The epithelial lining of the duodenum, called the "brush border," produces several digestive enzymes to break down: | -Maltose->2 glucose -Dipeptides (2amino acids)-> 2 free amino acids |
| ... is completed as peristalsis moves the chyme and digestive juices along the small intestine | Enzymatic digestion |
| Most digestion occurs in the ... | duodenum; the jejunum and ileum function mainly in absorption of nutrients and water |
| Absorption of digested nutrients occur mostly across the wall of the small intestine and into ... | nearby blood capillaries |
| The small intestine has a huge surface area, due to ... and ... that exposed to the intestinal lumen | villi; microvilli. The enormous microvillar surface greatly increases the rate of nutrient absorption |
| Each villus contains a network of blood vessels and a small lymphatic vessel called a ... | lacteal |
| After glycerol and fatty acids are absorbed by the epithelial cells, they are recombined into fats within these cells. Then, ... | these fats are mixed with cholesterol and coated with protein, forming molecules called chylomicrons, which are transported into lacteals |
| Amino acids and sugars pass through the epithelium of the small intestine and enter the ... | bloodstream |
| Capillaries and veins from the lacteals converge in the hepatic portal vein and deliver blood to the ... | liver (for processing) and then on to the heart. Liver processing includes: adjusting blood glucose level, adjusting blood amino acid levels, detoxify toxic nutrients. |
| The ... of the large intestine is connected to the small intestine | colon |
| The ... aids in the fermentation of plant material and connects where the small and large intestines meet | cecum |
| The human cecum has an extension called the ..., which plays a very minor role in immunity | appendix |
| A major function of the colon is to ... | recover water that has entered the alimentary canal |
| Wastes of digestive tract, the feces, become more solid as they move through the ... | colon |
| Feces pass through the rectum and exit via the ... | anus |
| The colon houses strains of bacterium ..., some of which produce vitamins B5, biotin, K | Escherichia coli |
| Feces are stored in the ... until they can be eliminated | rectum; These are feces composed of undigested food (cellulose) and intestinal bacteria |
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