Question | Answer |
Central Nervous System | Brain and spinal cord |
Peripheral nervous system (pns) | All nerves to spinal cord and other parts of the body |
Autonomic nervous system ( ANS) | Control of involuntary body functions ( ex heartbeat digestion ) |
Three parts of a neuron | Celll body , dendrite , Axon |
Cell body of neuron | main part |
Dendrites | branching projections that conduct impulses to the cell body of the neuron |
Axon | elongated projection that conducts impulses away from the cell body of the neuron |
Melanin sheets | Made of protein phospholipid layer around axon |
Three main types of connective tissue cells in SNS | Astrocytes, Microglia, Oligodendrocytes |
Astrocytes | star shaped cells that anchor small blood vessels to neurons |
Microglia | small cells that move in inflamed brain tissue carrying phagocytosis |
Oligodendrocytes | form myelin sheaths on axons in the CNS (Schwann cells form myelin sheaths in PNS only) |
Nerve | bundle of peripheral axons |
Tract | bundle of central axons |
Matter | brain or cord tissue composed primarily of myelinated axons (tracts) |
Gray matter | brain or cord tissue composed primarily of cell bodies and unmyelinated fibers |
Nerve coverings | fibrous connective tissue |
Endoneurium | surrounds individual fibers within a nerve |
Perineurium | surrounds a group (fascicle) of nerve fibers |
Epineurium | surrounds the entire nerve |
Nerve impulses (action potentials | are conducted from receptors to effectors over neuron pathways or reflex arcs; conduction by a reflex arc results in a reflex (that is, contraction by a muscle or secretion by a gland) |
Two-neuron arcs | • The simplest reflex arcs, sensory neurons synapsing in the spinal cord with motor neurons;
• Knee Jerk |
Three-neuron arcs | • Sensory neurons synapse in the spinal cord Interneuron synapse with motor neurons and spinal cord
• More complex response; involves an interneuron, in addition to sensory and motor |
action potentials | o A self-propagating wave of electrical disturbance that travels along the surface of a neuron membrane |
• Olfactory | from nose to brain |
• Optic | from eye to brain |
• Oculomotor | from brain to eye muscle |
• Trochlear | from brain to external eye muscles |
• Trigeminal | from skin and mucous of head and from teeth to the brain, also from brain to chewing muscles |
• Abduces | from brain to the external eye muscles |
• Facial | from taste buds of tongue to brain, from brain to face muscles |
• Vestibulocochlear | from ear to the brain |
• Glossopharyngeal – | From throat and taste buds of tongue to brain, also from brain to throat muscles and salivary glands |
• Vagus | from throat, larynx, and organs in thoracic and abdominal cavities to the brain, also from brain to muscles of throat and to organs in thoracic abdominal cavities |
• Accessory | from brain to certain shoulder and neck muscles |
• Hypoglossal | from brain to muscles of tongue
• Tongue movements |
o Sciatica | • Is inflammation of the sciatic nerve that innervates the legs |
o Neuralgia | • or muscle pain, often accompanies neuritis |
o Trigeminal neuralgia | • Recurring episodes of stabbing pain along one or more branches of the trigeminal (fifth cranial) nerve in the head |
o Bell palsy | • Paralysis of facial features resulting from damage to the facial (seventh cranial) nerve |
o Herpes zoster, or shingles | • Viral infection caused by chickenpox virus that has invaded the dorsal root ganglion and remained dormant until an episode of shingles |
o Autonomic nervous system | • Motor neurons that conduct impulses from the central nervous system to
• Cardiac muscle, Smooth muscle, glandular epithelial tissue; |
o Autonomic neurons— | • Preganglionic autonomic neurons conduct from spinal cord or brainstem to an autonomic ganglion |
o Autonomic or visceral effectors | • Tissues to which autonomic neurons conduct impulses
• Composed of two divisions—the sympathetic system and the parasympathetic system |
o Autonomic conduction paths | • Consist of two-neuron relays (that is, preganglionic neurons from the CNS to autonomic ganglia, synapses, postganglionic neurons from ganglia to visceral effectors) |
• Sympathetic Nervous System | o A chain of sympathetic ganglia is in front of and at each side of the spinal columno Serves as the emergency or stress system, controlling
o Change enduced fight-or-flight response |
• Parasympathetic Nervous System | o Parasympathetic preganglionic neurons have dendrites and cell bodies in the gray matter of the brainstem and the sacral segments of spinal cord
everyday system |
o Cholinergic fibers | eganglionic axons of parasympathetic and sympathetic systems and parasympathetic postganglionic axons release acetylcholine |
o Adrenergic fibers— | axons of sympathetic postganglionic neurons release norepinephrine (noradrenaline) |
• Autonomic Nervous System as a Whole | o Regulates the body’s automatic functions in ways that maintain or quickly restore homeostasis |
• Which neurons transmit impulses from the brain and the spinal cord | o Motor |
the most common primary diseases of the cns is a myelin disorder called | o Multiple sclerosis |
• Nerve impulses are also called __ because each one is a difference in charge that usually triggers an action by the cell | o Action potential |
• Identify the two morphine like neurotransmitters that function as inhibitors | o Endorphins and enkephalis |
• Which of these would not be found in the brain stem | o Thalamus |
• Which division of the nervous system function as emergency system | o Sympathetic |
• General senses | ➢ temperature, touch, pressure, pain and proprioception |
➢ Special senses | special organs of the head.
➢ sight, sound, taste, smell and balance |
Properties of Stimulus | • Sensory neurons are activated
• Neurons terminate in brain
• Each receptor type is most sensitive to a particular modality of stimulus |
Labeled Line coding | • 1:1 association of receptor with sensation . The brain associates a signal coming from a specific receptor with a specific modality. |
Properties of Stimulus: Intensity | ➢ Coded by number of receptors activated and frequency of action potentials |
Properties of Stimulus Duration | ➢ Coded by duration of action potentials
➢ Some receptors can adapt, or cease to respond |
• Action potential | ➢ Rapid and uniform electrical signal conducted down a cell membrane |
• Graded potential | ➢ Change in membrane potential whose magnitude is proportional to the stimulus and that decreases with distance as it spreads inside the cell membrane |
Receptor potential | • Change in sensory receptor membrane potential (graded potential in a special senses receptor |
• Meissner’s corpuscles | Fine touch |
Pacinian corpuscles | • Vibration |
Merkel receptors | Pressure/texture |
Temperature Receptors | Free nerve endings
Terminate in subcutaneous layers |
Nociceptors | pain |
The somatic senses include | itch, touch ,proprioception ( body n space)
pain |
Proprioreceptors monitor | limb and muscle position |
The minimum stimulus required to activate a sensory receptor is its _______. | threshold |
Which type of sensory information is NOT routed through the thalamus on its way to the brain | olfactory |
The intensity of a sensory stimulus is coded by _____. | the frequency of action potentials |
Fibers that carry the most rapid sensory signals are | myelinated and large diameter |
Ipsilateral means | on the same side |
Ascending sensory pathways cross the midline | in the brainstem and in the spinal cord) |
Visual Pathway | ➢ Innermost layer of retina contains rods and cones➢ Nerve impulse leaves the eye through the optic nerve; the point of exit is free of receptors and is therefore called a blind spot brain can process visual info |
Diabetic retinopathy | damage to retina from hemorrhages and growth of abnormal vessels associated with diabetes mellitus |
Glaucoma | increased intraocular pressure decreases blood flow in retina and thus causes retinal degeneration |
Nyctalopia | night blindness) or the inability to see in dim light is caused by retinal degeneration or lack of vitamin A
Age-related macular degeneration (AMD) (most common) |
External ear | Contains ceruminous glands ( secrete air wax)
➢ Inflammation called otitis media |
Inner Ear | semicircular canals, and cochlea |
Cells acted on by hormones | target cells found within target organs |
Hormones removed from blood by | Degrading enzymes
Kidneys
Liver |
Half-life | time required for hormone's blood level to decrease by half |
duration of Hormone Activity | ➢ Ranges from 10 seconds to several hours |
Nonsteroid and Steroid Hormones | Nonsteroid hormones (first messengers) bind to receptors on the target cell membrane, triggering second messengers to affect the cell’s activities |
Target Cell Activation | Target cell activation depends on three factors
➢ Blood levels of hormone
➢ Relative number of receptors on or in target cell
➢ Affinity of binding between receptor and hormone |
➢ Up-regulation | target cells form more receptors in response to low hormone levels |
➢ Down-regulation— | target cells lose receptors in response to high hormone levels |
Regulation of Hormone Secretion | • Negative feedback—mechanisms that reverse the direction of a change in a physiological system
o Maintain homeostatis , insulin
• Positive feedback—(uncommon) mechanisms that amplify
o Oxytosin child birth |
Prostaglandins | Diffuse only a short distance to act on cells in that tissue |
Anterior pituitary gland | ➢ Adeno = gland |
Posterior pituitary gland | neurohypophysis)
➢ Neuro = nervous |
TSH—• Thyroid-stimulating hormone | stimulates growth of the thyroid gland; also stimulates thyroid hormone release |
ACTH• Adrenocorticotropic hormone | stimulates growth of the adrenal cortex and glucocorticoids (mainly cortisol) release |
FSH• Follicle-stimulating hormone | initiates growth of ovarian follicles each month in the ovary and stimulates one or more follicles to develop to the stage of maturity and ovulation |
LH• Luteinizing hormone | Acts with FSH to stimulate estrogen secretion and follicle growth to maturity
Causes ovulation
Causes luteinization of the ruptured follicle |
GH- growth hormone | Stimulates growth by accelerating protein anabolism
Accelerates fat catabolism and slows glucose catabolism |
Prolactin (PRL) or lactogenic hormone | Stimulates breast development during pregnancy
Secretion of milk after the delivery of the baby |
ADH (Vasopressin) | Inhibits or prevents urine formation
Regulates water balance |
Oxytocin | ➢ Stimulates the pregnant uterus to contract
➢ May initiate labor |
Thyroid Gland | t3 10 times more active |
Function of Hormones | Insulin decreases the blood glucose by accelerating the movement of glucose |
hypoglycemia | excessive insulin secretion causes hypoglycemia |
➢ Ovaries produce | estrogens and progesterone |
Placenta secretes | estrogens, progesterone, and human chorionic gonadotropin (hCG |
➢ Adrenogenital syndrome | hyper secretion |
Thymus | ➢ Plays an important role in the development and function of the body’s immune system |
Placenta | Produces chorionic gonadotropins, estrogens, and progesterone
➢ Maintain the corpus luteum during pregnancy |
Pineal Gland | ➢ Glandular tissue predominates in children and young adults
➢ Becomes fibrous and calcified with age
Secretes melatonin |
• Normal volumes of blood | o Plasma-2.6 l
o Formed elements 2.4 l
o Whole blood- 4 to 6 L average or 7% |
RBC Abnormalities
Named according to size: | ➢ Normocytes- normal blood cell size
➢ Microcytic
➢ Macrocytixc |
Named according to hemoglobin content of cell: | ➢ Normochromic – normoal content of heboglobin
➢ Hypochromic
➢ Hyperchromic |
Polycythemia | Cause is generally cancerous transformation of red bone marrow
Dramatic increase in RBC numbers |
Anemia | Caused by low numbers or abnormal RBCs or by low levels or defective types of hemoglobin |
Leukocyte Types and Functions | ➢ Neutrophils
➢ Eosinophils
➢ Basophils |
Agranulocytes | monocytes in peripheral blood (macrophages in tissues); |
lymphocytes—B lymphocytes | ➢ Monocytes
➢ Lumphocytes |
White Blood Cell Disorders | ➢ Lymphoid neoplasms
➢ Myeloid neoplasms |
Multiple Myeloma | Cancer of B lymphocytes called plasma cells |
fibrous pericardium | There to protect the heart and anchor it in the body
Layers separated by fluid filled caviy t |
Heart chambers | ➢ Two upper chambers are called atria (receiving chambers)—right and left atria
➢ Two lower chambers called ventricles (discharging chambers discharge blood)—right and left ventricles |
myocardium | Wall of each heart chamber is composed of cardiac muscle tissue called |
Endocardium | smooth lining of heart chambers |
➢ Fossa ovalis | remnant of foramen ovale of fetal heart |
Interventricular septum | separates ventricles |
The Pulmonary and Systemic Circuits | Heart is transport system; two
side-by-side pumps
➢ Right side receives oxygen-poor blood from tissues (pulmonary circuit)
➢ Left side receives oxygenated blood from lungs systemic ) |
The Pulmonary and Systemic Circuits | ➢ Right atrium
➢ Left atrium |
Heart Valves | • Valves keep blood flowing through the heart; prevent backflow
• Atrioventricular (AV) valves |
Pulmonary semilunar | Beginning of the pulmonary artery |
Aortic semilunar | Beginning of the aorta |
Systemic circuit | ➢ Left atrium à mitral valve à left ventricle
➢ Left ventricle à aortic semilunar valve à aorta
➢ Aorta à systemic circulation |
• SA (sinoatrial) node | pace maker
o Sets pace for the rhythm of the heart |
• AV (atrioventricular) node | located in the right atrium interatrial septum |
• AV bundle | septum of ventricle |
• Purkinje fibers | in the wall of ventricle |
eeg trace | depolorization caused by p wave ,impulse delayed to av node, ventricular depolorization qrs atrial deplorization occurs ,ventricular depolorization complete, ventricular repolorization begings t wave, ventricular repolorization complete |
right side of the heart | recieves oxygen poor blood from tissue |
left side receives | oxygenated blood from the lungs |
vericosa veins | enlarged veins in which blood pools |
thrombophlebitis | vein inflammmation accompanied by clot formation |
bluish tint in fetal blood circulation | cyanosis |
how many pulse points are there | 9 |
vital signs | temperature , pressure , respiratory rate , pulse |
pulse | pressure caused by expansion of recoil arteries |
radial pulse | pulse taken at wrist |
pressure points | where arteries are close to body surface |
systolic pressure | less than 120 |
diastolic pressure | less than 80 |
hypertension | occurs when blood pressure exceeds 140/90 |
circulatory stock | failure of the circulatory system to deliver oxygen to the tissues adequately resulting in cell impairment |
cardiogenic stock | caused by heart failure |
hypovolemic shock | drop in blood volume that causes blood pressure and blood flow to drop ( hemorrhage) |
primary or essential hypertension | 90% hypertensive conditions no underlying caise |
secondary hypertension | due to identifiable disorders including obstructed renal arteries, kidney disease , and endocrine disorders ( hypothyroidism and cushings) |
hypotension | low blood pressure 90/60 |
homeostatic imbalance hypotension | orthoatatic hypotension, chronic hypotension , acute hypotension |