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Bio251 Hopkin Exam 1
Bio 251 Hopkin Exam 1
| Question | Answer |
|---|---|
| What are the two cell TYPES found in neural tissue? | neurons and neuroglial cells |
| Are there more neurons or neuroglial cells in the body? | There are 10 times more neuroglials than neurons |
| The nervous system has two major divisions, what are they? | The central nervous system and the peripheral nervous system. |
| What structures are included in the central nervous system? | brain and spinal cord |
| What structures are included in the peripheral nervous system? | everything else, most notably the cranial and spinal nerves |
| The peripheral nervous system is further divided into two major division, what are they? | the sensory and motor divisions |
| The motor division is further broken down into two units, what are they? | the somatic nervous system and the autonomic nervous system |
| Which of these systems (somatic or autonomic) controls skeletal muscle? | The somatic nervous system |
| Which of these systems (somatic or autonomic) controls smooth muscle, cardiac muscle (rate), and glands? | The autonomic nervous system |
| So wich one is under voluntary control (somatic or autonomic)? | The somatic nervous system |
| What are the three functions of the nervous system? | 1. sensory function 2. integrative function 3. motor function |
| What is included in the nervous system's sensory function? | sensory receptors gather information/stimuli and the information is carried back to the central nervous system |
| What is included in the nervous system's integrative function? | the inegrative function takes the sensory information and changes it into sensations, memory, thoughts and decisions (remember sensation originates in the brain and pain is all in your head) |
| What is included in the nervous system's motor function? | impulses are carried from CNA to effector organs. Decisions are acted upon |
| Which of the two cell types do most of the work and move information around? | neuron |
| Are neurons metabolically active and capable of reproduction? | They ARE metabolically active but usually do not reproduce. |
| What does a neuron's dendrite/s do? | receive's incoming signal. Branches of a cell body that create more surface area for receiving signals. |
| What does a neuron's cell body do? | manufactures cell components and integrates signals |
| What does a neuron's axon do? | conducts impulses, sends outgoing signals |
| What happens at the synaptic knob? | it is the site of contact with target cell. Location where impulse leaves one neuron's axon and chemically excites a dendrite of the next neuron. |
| What is a myelin sheath? | it is a covering produced by neuroglial cells to insulate axons. In peripheral neurons, it is missing at the point a node is formed. |
| What do nodes do? | they reinforce a signal along an axon and add another impulse at each node |
| Is myelination completed prior to birth? | no, it begins during fetal development but much of the myelination is formed during infancy |
| How many cells are there in a myelin sheath? | one schwann cell that keeps growing until it wraps around the axon 6 or 7 times |
| What do you call the naked portions of axon between schwann cells/myelin? | Nodes of Ranvier |
| Which structures contain myelinated axons, white matter or gray matter? | white matter |
| If white matter contains myelinated axons, what does gray matter contain? | unmyelinated structures such as cell bodies and dendrites |
| What are the five types of neuroglial cells? | 1. Schwann cells 2. Oligodendrocytes 3. Microglia 4. Astrocytes 5. Ependyma |
| Which type of neuroglial cell is found in the central nervous system and is phagocytic/immune cell? | Microglia |
| Are Schwann cells found in the CNS or PNS? | PNS and they can only myelinate one segment |
| What is the name of the myelin producing cell found in the CNS. This cell is capable of making multiple segments of myelin. | Oligodendrocyte |
| What is the name of the neuroglial cell found in the CNS that is star shaped, connects neurons to blood vessels and mops up excess ions to maintain electrlyte balance? | Astrocytes |
| What is the name of the neuroglial cell that is found in the CNS, is ciliaed and lines open spaces of the central canal and ventricals of the brain. This neuroglial cell makes CSF. | Ependyma (Ependymal cells) |
| There are three structural classifications of neurons, what are they? | 1. Bipolar (one axon, one dendrite) 2. Unipolar (one axon no dendrite) and 3. Multipolar (one axon, many dendrites) |
| What are the three functional classifications of neurons? | 1. Sensory neurons 2. Interneurons 3. Motor neurons |
| What are the characteristics of sensory neurons? | Sensory neurons are also called afferent neurons. They carry an impulse to the central nervous system (most are unipolar and some are bipolar) |
| What are the characteristics of interneurons? | There are more interneurons than any other type of neuron. Interneurons are found between two neurons and are exclusively located in the central nervous system. They are multipolar. |
| What are the characteristics of motor neurons? | Motor neurons carry impulses away from central nervous system to effectors. They are multipolar |
| What are effectors? | they can be muscular tissue or glandular tissue. |
| Which ion is predominantly found outside of an axon? | Na+ (sodium) |
| Which ion is predominantly found inside of an axon? | K+ (potassium) |
| Does the sodium/potassium pump transport an equal number of sodium and potassium ions? | No. It pumps 2 K+ (potassium) for every 3 Na+ (sodium). |
| Which ion is larger? K+ or Na+? | K+ |
| Are the eyes, ears and nose in the CNS or PNS? | the PNS |
| What do you call the cell membrane of an axon? | axolemma |
| What do you call the cytoplasm of an axon? | axoplasm |
| How are ions distributed during an axon's resting potential? | Inside the axon is a high concentration of K+ and a low concentration of Na+. Outside the axon is the opposite, low concentration of K+ and a high concentration of Na+. |
| During resting potential, is the inside of the axon's net charge positive or negative? | inside is negative |
| During resting potential is the outside of the axon positive or negative? | outside is positive and the ions line up around the outside of the axon because they are attracted to the negative net charge inside the axon. |
| What is stronger, the chemical gradient caused by ion concentrations or the sodium/potassium pump? | the chemical gradient. |
| What mechanism actively transports Na+ out of an axon? | The sodium potassium pump? |
| Does the sodium-potassium pump move K+ in or out of the axon? | It move K+ into the axon |
| What does it take to "run" the sodium/potassium pump? | ATP |
| What kinds of stimuli can create local potential changes? | temperature, light, pressure e.g. absorbing light in the eye causes a protein to change shape. |
| What protein changes shape in response to stimuli? | The gated ion channel |
| Does this process always open the same amount of ion channels? | No. The number of ion channels opened depends on the strength of the signal/stimuli |
| When a stimuli is received, does this stimuli polarize or depolarize the axon? | it depolarized the axon...very quickly |
| Which segment of an axon is the "trigger zone"? | the first segment |
| What is the magic voltage number that opens the voltage gated ion channels? | -55 |
| What is the voltage number of an axon at resting potential? | -70 |
| What is the voltage of an axon that has been depolarized? | 0-35 |
| What part of the axon experiences a voltage change first? | the first/beginning segment (trigger zone) |
| So what drives an axon's potential changes? | voltage changes, when they hit -55, they open |
| At rest, is an axon polarized, at threshhold or repolarizing? | it is polarized |
| After a stimulis opens gated ion channels, and the voltage reaches -55, what is reached? | The threashold stimulus is reached |
| Once the threshold stimulus is reached, what happens? | the sodium channels open and the membrane depolarizes (charges inside and outside of cell balance) (Voltage 0-35) |
| What is happening during repolarization? | potassium channels open, sodium channels close, potassium leaves the cell and the membrane repolarizes. |
| What is another name for an action potential? | a nerve impulse |
| Do sodium channels stay open a long time? | no, just long enough to depolarize THAT segment of the axon (then the next sodium channel opens and depolarized the next segment of the axon) |
| How many action potentials can a nerve impulse make per second? | up to 250 per second |
| What is meant by the "all or none response"? | the neuron responds completely if it responds at all. |
| Can nerve impulses vary in strength? | no, all impulses carried on an axon are the same strength. |
| How can a nerve impulse create a bigger response? | it can increase the frequence of the signal |
| When threshold is reached, what is the voltage and what channels open? | voltage is -55 and sodium channels open |
| During depolarization, what is the voltage and what channels close | voltage rises past 0 and sodium channels close |
| During repolarization, what gates open? | Potassium gates open and potassium exits the membrane |
| What is the refractory period? | It is the period of time that a segment of an axon is unable to receive additionally stimulation. That segment of the axon needs to repolarize before it can react to the next stimulus. |
| There are actually two levels of the refractory period. Absolute refractory period and relative refractory period. When is the absolute refractory period? | when sodium gates are open. Absolutely no stimulus can trigger an action potential. |
| When is the "relative refractory period"? | When the K+ gates are open. Only a really big stimulus can trigger a new action potential. |
| Does the refractory period happen across the entire axon at the same time? | No. Only one segment at a time. |
| How many steps does it take to close a sodium gate? | 2, one to close the gate and one to return the protein to its original shape. |
| What net ion changes are more dramatic, sodium or potassium? | sodium changes are much much larger than potassium changes |
| In electrical terms, what does a large gauge wire and insulation do for an electrical current? | it increases the speed of the electrical current |
| What is meant by the term "saltatory conduction"? | In mylinated axons, segments are myelinted with nodes found between the myelinated segments. The ion changes caused by a nerve impulse unly occur in the nodes and the signal jumps from node to node. This method of conduction travels 10 times as fast. |
| After the impulse travels through to the end of the axon, how does the signal move to the next neuron's dendrite? | It crosses the synapse by releasing neurotransmitters from the synaptic knob. |
| What is a synaptic knob? | it is a small enlarged bulb with vessicles full of neurotransmitters |
| How do vessicles release the neurotransmitters? | by exocytosis |
| What is the predominat neurotransmitter in skeletal muscle? | acetylcholine |
| What are the two types of synaptic potentials? | EPSP and IPSP (Excitatory post synaptic potential) and (Inhibitory post synaptic potential) |
| What does EPSP (excitatory postsynaptic potential) mean? | the membrane of the post synaptic neuron depolarizes, and it makes the action potential more likely |
| What does IPSP (inhibitory postsynaptic potential) mean? | the membrane of the postsynaptic neuron hyperpolarizes and it makes an action potential less likely. |
| What is the "summation" of EPSP's and IPSP's? | Since most neurons have multiple synapses, the neuron cell body has to add up all of the potentials |
| What is temporal summation? | temporal summation adds the amount of impulses received in a period of TIME (fraction of a second), more impulses create a larger action potential |
| What is spatial summation? | if an excitatory and an inhibitory potential is received simultaneously, they will cancel eachother out. Can also mean if two or more ESPS or IPSP potentials are received simultaneously they will produce a larger inhibitory or excitatatory response |
| What is another term for summation? | integration (the net effect of inputs decides how the neuron proceeds) |
| In the synaptic cleft, what takes longer, sending a signal or clearing a signal. | It takes longer to clear a signal |
| What three ways can a "cessation of the sigal" occur? | 1. diffusion of neurotransmitters out of the cleft 2. the enzyme acetylcholinesterase chops up the acetylcholine 3. Reuptake of monoamines or amino acids occur (neurotransmitters) |
| Which neurotransmitter do somatic (skeletal muscle) neurons use? | acetylcholine |
| The alzheimer drug Aricept inhibits the breakdown of acetylcholine, what enzyme does it inhibit? | acetylcholinesterase |
| What do histamines produce? | release in hypothalamus produces alertness |
| What do MAOI drugs do? | inhibit the enzymes that break down dopamine |
| Cocaine is a dopamine agonist, what does it do? | It "pushes" the dopamine button (per Hopkin in lecture) |
| What does norepinephrine do? | creates sense of feeling good. low levels lead to depression |
| What does dopamine do? | also creates a sense of feeling good, deficiency accociated with Parkinson's |
| What does serotonin do? | It is primary inhibitory, leads to sleepiness |
| What does GABA do? | it is generally inhibitory (this is all slide says) |
| What does glutamate do? | it is generally excitatory (this is all the slide says) |
| What does substance P do? | it is excitatory and is associated with pain perception |
| What do endorphins and enkephalins do? | they are generally inhibitory and reduce pain by inhibiting Substance P release |
| What does nitric oxide do? | may play a role in memory and affects vasodilation. |
| What are meninges? | the three membranes that protect the central nervous system |
| What is the dura mater? | thick connective tissue that foms the outer layer of the meninges. In the cranium, it is attached to the skull bones, houses nerves and blood vessels and in some parts of the cranium forms two layers. It is found as a single layer in the spinal cord |
| What is the arachnoid mater? | thin weblike membrane with NO blood vessels. Lies between the pia mater and the dura mater |
| What is the pia mater? | is thin and delicate, also houses many nerves and blood vessels, it follows the countors of the brain |
| What is the fluid filled space between the arachnoid mater and the pia mater? | the subarachnoid space |
| What is typically found in the dural space between two layers of the dura mater in the skull? | large veins. Also, CSF is absorbed into the bloodstream through the dural sinuses |
| What are ventricles? | They are interconnected spaces within the brain and brain stem that are continuous with the central canal of the spinal cord and are filled with cerebrospinal fluid |
| What lines the ventricles and makes CSF? | ependymal cells |
| Once the CSF is produced in the ventricles, where does it go? | the subarachnoid space. (CSF is always circulating) |
| What is the epidural space primarily filled with? | fat |
| Where are the lateral ventricles? | the largest two ventricles, they are comma shaped structures found in the left and right hemispheres of the cerebrum |
| Where is the third ventricle? | it is located midline of the brain beneath the corpus callosum |
| Where is the cerebral aquiduct? | connects the third ventricle to the fourth ventricle. A malformation of this structure is the cause of the birth defect hydrocephalus. |
| Where is the fourth ventricle? | between the pons and the cerebellum (in front of the cerebellum) it is continuous with the central canal of the spinal cord |
| What is the composition of CSF? | it is clear and watery and similar to plasma but NO Protein and a little glucose (CSF is the interstitial fluid of brain cells) |
| What is the choroid plexus? | A structure in the ventricles where CSF is produced, forms the blood brain barrier, is lined with ependymal cells which secrete CSF. |
| What are the three major areas that CSF flows through? | ventricles, central canal and subarachnoid space |
| What are the functions of CSF? | it nourishes, protects and maintains stable ion cencentrations |
| In the spinal cord, there are two "enlargements", where are they and what do they do? | they are enlarged areas of the spinal cord in the cervical and lumbar regions that contain many interneurons and perform a lot of activity |
| Where does the spinal cord "end"? | Between L1 and L2 (Lunbar punctures are performed below L3) |
| Where does CSF circulation end? | it is absorbed into the dural sinuses and returned to the blood stream |
| Where does CSF move to after the subarachnoid space? | the dural sinuses and then back into the blood |
| What are arachnoid granulations? | small protrusions of the arachnoid mater through the dura mater. They protrude into the venous sinuses of the brain, and allow cerebrospinal fluid (CSF) to exit the brain, and enter the blood stream. |
| In the spinal cord, where do you find the gray matter? | In the "gray butterfly" in the middle |
| What are the two grooves that extend the length of the spinal cord dividing it into left and right halves? | the anterior medial fissure and the posterior median sulcus |
| What do you call the upper and lower wings of gray matter? | the posterior horns and the anterior horns |
| What do you call the sides of the butterfly of gray matter? | the left and right lateral horns |
| What part of the spinal cord supplies nerves to the upper limbs? | the cervical enlargement |
| What part of the spinal cord supplies nerves to the lower limbs? | the lumbar enlargement |
| The spinal cord consists of 31 segments that that each give rise to a a pair of what? | spinal nerves |
| What is the name of the area where the spinal cord stops? | conus medullaris |
| What do you call the loose nerves that extend beyond the conus medullaris? | the cauda equina |
| What do you call the horizontal bar of gray matter in the middle of the spinal cord? | the gray commisure |
| What do you call the three regions of white matter on each side? | anterior, posterior and lateral funniculi |
| The funniculi house longitudinal bundles of myelinated nerve fibers (axons) that make up major nerve pathways, what are they called? | nerve tracts |
| The "puppy ears" on either side of the spinal column are called what? | dorsal root ganglions |
| What do you call the area that connects the dorsal root ganglions to the spinal column? | the dorsal root of spinal nerve |
| What are the two spinal cord functions? | center for spinal reflexes and conduit for nerve impulses to and from the brain |
| What are the five essential components of a reflex arc? | 1. sensory receptor 2. sensory or afferent neuron 3. CNS(brain or spinal cord) 4.motor or efferent neuron 5. effector muscle or gland |
| What are reflex arcs? | automatic, subconscious responses to stimuli |
| Where is a sensory receptor? | at the dendritic end of a sensory neuron |
| what does afferent mean? | towards cns |
| what does efferent mean? | towards effectors/out of cns |
| What are the characteristics of the knee-jerk reflex/patellar reflex? | simple monosynaptic reflex (only uses 2 neurons), helps maintain posture,involves stretch receptors in the quadriceps femoris send signal to spinal cord which send impulse along motor neuron back to quad.femoris.The muscle contracts and the leg extends |
| What are the characteristics of a withdrawl reflex? | (polysynaptic reflex) painful stimuli activate skin receptors that send sensory impulse to spinal cord, impulse passes to interneurons of a reflex center then back out to motor neurons whick signal a muscle to pull away. Prevents tissue damage |
| what is a monosynaptic reflex? | it only involves 2 neurons, a sensory neuron and a motor neuron |
| What is a crossed extensor reflex? | (polysynaptic reflex) at the same time a withdrawl reflex is happening, this reflex affects muscles of the OTHER limb. flexor is inhibited, extensor contracts and the body maintains upright posture |
| What does decussation mean when discussing spinal nerve tracts? | it means a fiber crosses sides |
| Are corneal and pupillary reflexes spinal reflexes? | no they are brain stem reflexes |
| What is an ascending tract? | a nerve tract that conducts sensory impulses to the brain |
| What path does a sensory impulse follow? | sensory receptor to second order neuron to third order neuron to brian (the movement from one neuron to another is called decussation) |
| What does the brain do? | interprets sensations, determines perception, stores memory, reasoning, makes decisions, coordinates muscular movements, regulates visceral activities, determines personality |
| What is the cerebrum? | consists of two cerebral hemispheres connected by a bridge of nerve fibers called the corpus callosum |
| What are gyri? | the bumps or ridges in the cerebrum |
| what are sulci? | grooves |
| what is the longitudinal fissure? | a very deep groove that separates the left and right cerebral hemispheres |
| what is the transverse fissure? | separates the cerebrum from the cerebellum |
| What are the 5 loves of the cerebrum? (all are present on each side) | frontal, parietal, temporal, occipital, insula |
| What divides the frontal and parietal lobes? | the central sulcus (kind of spans from ear to ear) |
| What do you call the white matter connection between the left and right cerebral hemispheres? | the corpus callosum |
| What are the general functions of the cerebrum? | (highest mental functions) interpreting impulses, innitiating voluntary movements, storing information as memory, retrieving stored information, reasoning, center for intelligence and personality, hearing, sight, touch, smell |
| what is procedural memory? | muscle memory stored in cerebellum |
| What is explicit memory? | memories you can talk about |
| What is the cerebral cortex? | thin layer of gray matter that constitutes the outtermost portion of the cerebrum. contains 75% of all neurons in the nervous system |
| In the cerebrum, what and where are primary the motor areas? | they are found in the frontal lobes, in front of the central sulcus and control voluntary muscles |
| In the cerebrum, what and where is broca's area? | IT (only one) is found in a frontal lobe, in front of the central sulcus and in front of primary motor cortex (temple area). Controls muscles needed for speech and is usually found on the left but occasionally found on the right |
| In the cerebrum, what and where is the frontal eye field? | it is above Broca's area and controls voluntary movements of the eyes and eyelids |
| Which has a larger motor area, muscles of the hand or muscles of the butt? | hand |
| What general area of the cerebral cortex houses sensory areas? | shaped like a headband just behind the central sulcus |
| In the cerebrum, what and where are the cutaneous sensory areas? | they are in the parietal lobes and interpret sensations of the skin |
| In the cerebrum, what and where are the visual areas? | they are in the occipital lobes and interpret vision |
| In the cerebrum, what and where are the auditory areas? | they are in the temporal lobes and interpret hearing |
| What are association areas? | other regions of the cerebral cortex that are not primary motor or primary sensory. They are widespread throughout the cerebral cortex, analyze and interpret sensory experiences, provide memory, reasoning, verbalization, judgement and emotions |
| What do frontal lobe association areas do? | concentrating, planning, problen solving, judging (most developed in humans) |
| What do parietal lobe association areas do? | understanding speech, using words to express thought |
| What do temporal lobe association areas do? | remember visual scenes, remember music, remember complex patterns |
| What do occipital lobe association areas do? | combine visual images with other sensory experiences |
| What is the function of tracts (bundles of myelinated axons) of cerebral white matter? | the gray matter areas are connected by white matter tracts |
| If white matter tracts are busses, what do you call an imulse that gets off the a-line and hops on the c-line? | decussation |
| In most of the population, what hemisphere is dominant? | left |
| What does the dominant hemisphere control? | speech, writing, reading, verbal skills, analytical skills, conputational skills |
| What does the non-dominant hemisphere control? | nonverbal tasks, motor tasks, understanding and interpreting musical and visual patterns, provides emotional and intuitive thought processes (also inflections, expressions of emotion/nonverbal speech) |
| What information is saved in short term memory? | working memory (is a closed circuit), the circuit is stimulated over and over, when impulse flow stops, the memory disappears |
| What information is saved in long term memory? | changes are made to the structure and function of neurons, produces enhanced synaptic transmission |
| What area of the cerebrum is located deep within the cerebral hemispheres, works on dopamine, and is necessary for making smooth graceful movement. Compares intended movement with actual movement and makes correction (damage is cause of parkinson's)? | basal nuclei |
| Where is the diencephalon located? | between the cerebral hemispheres and above the brain stem (it surrounds the third ventricle) |
| What structures are included in the diencephalon? | thalamus, hypothalamus, optic tracts, optic chiasm, pituitary, pineal gland |
| What does the thalamus do? | gateway for sensory impulses heading to cerebral cortex, receives all sensory impulses except smell, channels impulses to appropriate part of cerebral cortex for interpretation |
| What does the hypothalamus do? | it is the link between the endocrine and nervous systems, maintains homeostasis by regulating visceral activities, e.g. regulates temperature |
| What parts of the brain are included in the limbic system? | portions of frontal and temporal lobes, hypothalamus, thalamus, basal nuclei and other deep nuclei |
| What does the limbic system do? | aka "primative brain", controls emotions, produces feelings, interprets sensory impulses |
| What are the three parts included in the brain stem? | midbrain, pons, medulla oblongata |
| Where is the midbrain and what does it contain? | it is between the diencephalon and the pons, it contains bundles of fibers that join lower parts of the brain stem and spinal cord with higher parts of the brain (contains the cerebral aquiduct which connects the third and fourth ventricles) |
| Where is the pons and what does it do? | it is the rounded bulge on the underside of the brainstem between medulla oblongata and midbrain. It helps regulate the rate and depth of breathing and relays nerve impulses to and from medulla oblongata and cerebellum |
| Where is the medulla oblongata and what does it do? | enlarged continuation of the spinal cord, conducts ascending and descending impulses between brain and spinal cord,contains cardiac,vasomotor and respirtory control centers,also contains nonvital reflex control centers:coughing, sneezing, vomiting |
| Where is the reticular formation and what does it do? | complex network of nerve fibers scattered throughout the brain stem, connects to centers of hypothalamus,basal nuclei, cerebellum and cerebrum. filters incoming sensory information and arouses cerebral cortex into state of wakefulness.blocks out clothes |
| What are the two major types of sleep? | slow wave and rapid eye movement |
| What are the characteristics of slow wave sleep? | person is tired, decreases activity of RAS, restful, dreamless, lower BP and respirs, can be light or heavy, alternates with REM sleep. |
| What are the characteristics of rapid eye movement sleep (REM)? | some areas of the brain are very active, heart and respir rates irregular, dreaming occurs |
| Where is the cerebellum and what is it's structure? | it is behind the occipital lobes as well as the pons and medulla. has 2 hemispheres, has a cerebellar cortex (outer layer: molecular layer, inner: granular layer), an arbor vitae "tree of life" of white matter |
| What does the cerebellum do? | it integrates sensory information concerning the position of body parts, it coordinates muscle activity, maintains posture, has large purkingie cells |
| What facilitates the formation of long term memory? | sleep! specifically REM sleep |
| What do you have to turn off to go to sleep,other than the light? | the reticular formation (inhibitory neurotransmitters are released during slow wave sleep) |
| What is faster, unconscious responses or conscious responses? | unconscious responses |
| Why is the pons larger in humans? | it houses connections to cerebellum that coordinate smooth and graceful movements. Humans have greatest need and ability for smooth and graceful movements. |
| How may pairs of cranial nerves are there? | 12 pairs - arising from the brain and communicating with other parts of the body |
| How many pairs of spinal nerves are there? | 31 pairs - arising from the spinal cord and communicating with other parts of the body |
| What do both cranial and spinal nerves have? | somatic fibers connecting to the skin and skeletal muscles; autonomic fibers connecting to the viscera |
| What is endoneurium? | covers sensory nerve fibers |
| What is endomysium? | covers muscle nerve fibers |
| are cranial nerves and spinal nerves part of cns or pns? | pns |
| What are the two major subdivisions of the pns? | the somatic nervous system (skin and skeletal muscles and conscious activities) and the autonomic nervous system (connects cns to viscera such as organs and glands) |
| What is/are the basal nuclei? | masses of gray matter deep within the cerebral hemispheres. Relay stations for motor impulses originating in the cerebral cortex and passing into the brainstem and spinal cord |
| What are the three types of nerve and nerve fiber classification? | sensory nerves (only carry sensory impulses), motor nerves (only involved in muscle control) and mixed nerves (have both sensory and motor fibers) |
| What do general somatic efferent fibers do? | carry motor impulses from cns to skeletal muscles |
| What do general visceral efferent fibers do? | carry motor impulses from cns to smooth muscle and glands |
| What do general somatic afferent fibers do? | carry sensory impulses from receptors to the cns |
| What do general visceral afferent fibers do? | carry sensory impulses from blood vessels and internal organs to the cns |
| What is perineurium? | covers a fasicle of nerve fibers |
| What is epineurium? | covers a bundle of many fasicles of nerve fibers |
| What is the name of the first pair of cranial nerves? | I. Olfactory nerves (sensory) |
| What do the olfactory nerves do? | provide sense of smell |
| What is the name of the second pair of cranial nerves? | II. Optic nerves (sensory) |
| What do the optic nerves do? | provides vision, crosses at chiasma |
| What is the name of the third pair of cranial nerves? | III. Oculomotor nerves (primarily motor) |
| What do the oculomotor nerves do? | provides some eye movement, opening of eyelid, constriction of pupil, focusing |
| What is the name of the fourth pair of cranial nerves? | IV. Trochlear nerves (primarily motor) |
| What do the trochlear nerves do? | provides ability to rotate the eye inferiolaterally |
| What is the name of the fifth pair of cranial nerves? | V. Trigeminal nerves (mixed) |
| What do the trigeninal nerves do? | Trigeminal means three branches:(opthalmic division-sensory, maxillary division-sensory, mandibular division-motor) controls skeletal muscles of mandible (chewing), provides for sensation in the mouth and sensation of and around the eyes |
| What is the name of the sixth pair of cranial nerves? | VI. Abducens nerves (primarily motor) |
| What do the abducens nerves do? | provide the ability to rotate eye laterally |
| What is the name of the seventh pair of cranial nerves? | VII. Facial nerves (mixed) |
| What do the facial nerves do? | facial expressions, sense of taste on front 2/3 of tongue, salivary glands, and tear, nasal and palentine glands (5 branches: temporal, zygomatic, buccal mandibular, cervical, stylomastoid foramen) |
| What is the name of the eighth pair of cranial nerves? | VIII. Vestibulocochlear nerves (sensory) |
| What do the vestibularcochlear nerves do? | provides hearing and sense of balance (innervates structures of the inner ear) |
| What is the name of the ninth pair of cranial nerves? | IX. Glossopharyngeal nerves (mixed) |
| What do the glossopharyngeal nerves do? | control of swallowing, salivation, gagging, sensations of posterior 1/3 of tongue, carotid BP and pH receptors |
| What is the name of the tenth pair of cranial nerves? | X. Vagus nerves (mixed) |
| What do the vagus nerves do? | vagus means wanderer in latin. controls swallowing, speech, and regulation of viscera (lung, heart, spleen, liver, stomach, kidney, colon, small intestine |
| What is the name of the eleventh pair of cranial nerves? | XI. Accessory nerves (primarily motor) |
| What do the accessory nerves do? | controls swallowing as well as head, neck and shoulder movement |
| What is the name of the twelveth pair of cranial nerves? | XII. Hypoglossal nerves (primarily motor) |
| Hat do the hypoglossal nerves do? | provides the tongue movements of speech, food manipulation and swallowing |
| What is the name of the thirteenth pair of cranial nerves? | haha just kidding. |
| Are cranial nerves CNS or PNS? | PNS! |
| Are dorsal root ganglions cns or pns? | pns |
| There are 31 pairs of spinal nerves, where do they originate from? | 8 cervical(one before c1, the rest below c1-c7 but numbered C1-C8), 12 thoracic (t1-t12), 5 lumbar (L1-L5), 5 sacral (S1-S5), 1 coccygeal (C0) |
| What is a dorsal root? | It is posterior to the spinal column and is where sensory nerve axons attach to the vertebral column? |
| What is the dorsal root ganglion? | it is the bulge on the dorsal root that houses the cell bodies of sensory neurons |
| What is a ventral root? | They are on the ventral (front) side of the spinal column where axons from motor neurons attach to the vertebral canal |
| What is a ventral root ganglion? | ventral roots don't have ganglions |
| dorsal roots and ventral roots join to form what? | spinal nerves (which then exits the spinal column through intervertebral foramen) |
| What is a dermatome? | an area of skin that the sensory nerve fibers of a particular spinal nerve innervate (like a skin chart of what spinal nerves innervate what portion of skin) Every area covered by 2 spinal nerves |
| What is a nerve plexus? | it is a complex network of fibers from mutiple spinal nerves that are sorted and recombined so they all reach a particular body part. (even though the fibers originate from different spinal nerves) |
| What are some things we should know about cervical plexus? | C1-C4, lies deep in the neck, supplies muscles to skin and neck, contributes to phrenic nerve (phrenic nerve controls diaphragm) |
| What are some things we should know about brachial plexus? | C5-T1, deep within shoulders, includes musculocutaneous nerves, ulnar nerves, radial nerves, axillary nerves (pretty much a whole arm) |
| What are some things we should know about lumbosacral plexus? | T12-S5, extends from lumbar region to pelvic cavity, obturator nerves, femoral nerves, sciatic nerves plus tibial and fibular fibers (pretty much a whole leg) |
| Is the autonomic nervous system part of CNS or PNS? | PNS. it functions independantly, without conscious effort. |
| What does the autonomic nervous system do? | Controls visceral activity, regulates smooth muscle, cardiac muscle, and various glands. Manages heart rate, BP, respirs, temp and other visceral activities that aid in homeostasis. Also controls fight or flight response |
| What are the two divisions of the autonomic nervous system? | sympathetic (fight or flight) and parasympathetic (rest and digest) (so ANS can increase HR during stress and then decrease HR after stressful event is over) |
| Are autonomic nerve fibers motor or sensory? | the afferent sensory nerve fibers are not part of the ANS just the efferent motor nerve fibers. The efferent motor fibers run through ganglia which provides the autonomic nervous system some independence from brain and spinal cord |
| what is a preganglionic fiber (part of autonomic nervous system)? | The first of a 2 nerve fiber/axon system that carries an efferent impulse from the brain or spinal cord to an automonic gangion |
| What is a postganglionic fiber (part of autonomic nervous system)? | The second of a 2 nerve fiber/axon system. After the first one meets up with an autonomic ganglion, this one takes the signal to the visceral effector organ |
| What are paravertebral ganglia? (paravertebral means beside the vertebral column) | They are beside and paralel with the spinal column and link fibers from the sympathetic nervous system. Per lecture, the nerve fibers must travel long distances and this is reason that sympathetic responses are generalized. |
| What neurotransmitter do all autonomic preganglionic fibers use? | acetylcholine, same as muscle fibers |
| Does the sympathetic division of the autonomic nervous system have ganglia near their target organs? | no |
| Does the parasympathetic division of the autonomic nervous system have ganglia near the target organs? | yes. short postganglionic fibers. This accounts for a more specific response e.g. change in pupil size doesn't change heart rate |
| What determines the effects of the autonomic nervous system? | the types of neurotransmitters released and the types of receptors on target cells. |
| What controls the autonomic nervous system? | Mostly the brain and spinal cord (only some is controlled independently with integration in the ganglia)medulla regs cardiac, vasomotor and repir activities, hypothalamus regs visceral function,limbic system and cerebral cortex controls emotions |
| What do cholinergic fibers release and where are they found? | they release acetylcholine and are found in preganglionic sympathetic and parasympathetic fibers as well as post ganglionic parasympathetic fibers |
| What do adrenergic fibers release and where are they found? | they release epinephrine and norepinephrine (aka adrenaline and noradrenaline) and are found in postganglionic SYMPATHETIC fibers (some receptors are alpha and some are beta) |
| What two types of cholinergic receptors can acetylcholine combine with? | muscarinic and nicotinic |
| Where are muscarinic receptors found? | receptors are in the membranes of effector cells at the ends of all postganglionic PARASYMPATHETIC nerve fibers. slow response |
| Where are nicotinic receptors found? | in the synapses between preganglionic and postganglionic neurons of the SYMPATHETIC and PARASYMPATHETIC pathways. fast response |
| What is the reticular activating system? | is an area of the brain (including the reticular formation and its connections) responsible for regulating arousal and sleep-wake transitions. |
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