Mcat Bio 13, Nervous System Real

Front 1

What is the cell body of a neuron also called?

Back 1

Soma

Front 2

Why is the nerve terminal shaped the way it is?

Back 2

enlarged and flattened to maximize neurotransmission to the next neuron and ensure proper production of neurotransmitter

Front 3

What the two main ions relevant to action potentials in neurons? What are their relative concentrations inside/outside the cell at resting potential?

Back 3

Na and K
outside: high Na, low K
inside: high K, low Na

Front 4

How do neurons obtain their negative resting potential?

Back 4

-Na/K ATPase (3Na out/ 2K in), moves against gradient
-membrane has a greater permeability to K+ compared to Na+ (K+ diffuses down its gradient out of the cell)

Front 5

What causes sodium to move into the cell during depolarization? What is the voltage after depolarization?

Back 5

-Electric and chemical gradient (inside negative, more sodium outside)
-+35mv

Front 6

The speed of the action potential depends on what?

Back 6

-resistance in the neuron
-want a neuron that is thicker and shorter
-myelin is a good insulator, prevents the loss of electrical signals

Front 7

What do you call a neuron that signals to a gland or muscle?

Back 7

Effector cell

Front 8

The release of neurotransmitters is dependent on what substance?

Back 8

Calcium

Front 9

How are neurotransmitters removed from the synaptic cleft?

Back 9

1. enzymes (acetylcholinesterase on acetylcholine)
2. reuptake carriers- recycled into the presynaptic neuron (dopamine or serotonin)
3. diffuse out of the area (nitric oxide)

Front 10

What are sensory neurons called?
Motor neurons? Neurons only involved in local circuits?

Back 10

Sensory=afferent neurons
Motor=efferent

Front 11

Axons bundled together are called what? Cell bodies that are clustered together are called what?

Back 11

Nerves (sensory, motor, or mixed)
Cell bodies in PNS= ganglia
Cell bodies in CNS=nuclei

Front 12

What are three major divisions of the brain?

Back 12

1. forebrain
2. midbrain
3. hindbrain

Front 13

The forebrain can further be broken down into what?

Back 13

1. telencephalon (frontal, pareital, occipital, temporal lobes. Also, cerebral cortex)
2. diencephalon (thalamus and hypothalamus)

Front 14

What connects the right and left hemispheres of the brain?

Back 14

corpus collosum

Front 15

What is the function of the thalamus?

Back 15

gateway to the brain, recieves sensory information before being relayed to the cortex

Front 16

What is the function of the midbrain?

Back 16

-serves as a relay point between more peripheral structures and the forebrain
-passes sensory/visual information to forebrain
-receives motor instruction from forebrain, passes to hindbrain

Front 17

T/F spinal cord can participate in simple reflex arcs of its own.

Back 17

T

Front 18

Describe the white/gray matter in the spinal cord:

Back 18

Gray matter is deep to the white matter.
-white matter contains axons
-gray matter contains cell bodies

Front 19

Describe the sensory and motor neuron in the spinal cord:

Back 19

Sensory neuron- bring info from the periphery; enter on dorsal (back) side of the spinal cord
*cell bodies found at dorsal root ganglion
Motor: exit spinal cord ventrally

Front 20

How many components does the peripheral nervous system have?

Back 20

-12 pairs of cranial nerves
-31 pairs of spinal nerves

Front 21

What is the Somatic nervous system responsible for?

Back 21

voluntary movement and reflexes

Front 22

Two divisions of the autonomic nervous system?

Back 22

Sympathetic nervous system (fight or flight)
Parasympathetic nervous system (rest and digest)

Front 23

What is the primary difference between the autonomic nervous system and the somatic nervous system?

Back 23

autonomic nervous system- two neuron system
somatic nervous system- motor neuron goes directly to the muscle

Front 24

In the autonomic nervous system, what are the two neurons called?

Back 24

1. preganglionic neuron- soma in the Central Nervous System, axon travels to peripheral nervous system
2. postganglionic neuron

Front 25

In the sympathetic and parasympathetic nervous system, what do the neurons use as their neurotransmitters for the pre/postganglionic neuron?

Back 25

Sympathetic
-preganglionic use acetylcholine (can cause release of epinephrine from the adrenal medulla)
-postganglionic use norepinephrine
Parasympathetic
-use acetylcholine for both

Front 26

Name four types of sensory neurons:

Back 26

1. interoceptors- internal environment (blood volume, blood pH, partial pressure)
2. propioceptors- motor position
3. exteroceptors- external environment, light, sound, touch, taste, pain, and temperature
4. nociceptors- sense pain, tell brain

Front 27

What happens in the eye after excitation of the photoreceptors on the cornea?

Back 27

-photoreceptors send a signal to teh bipolar cells
-relay info to the retinal ganglion cells
-axons of the ganglion cells bundle to form the optic nerve

Front 28

What causes the blind spot in our eyes?

Back 28

-displacement of photoreceptors by the optic nerve
-not a problem because of two eyes

Front 29

What does the outer ear consist of?

Back 29

auricle and auditory canal

Front 30

How is sound transformed into electrical signals?

Back 30

-outer ear collects waves
-channels them to the tympanic membrane
-vibration of tympanic membrane cause ossicles to move back and forth
-ossicles transmit information through the oval window to the fluid-filled inner ear
-this creates fluid waves in the inner ear that depolarize hair cells of the cochlea

Front 31

Where do the action potentials of the hair cells travel?

Back 31

-along the auditory nerve to the brain

Front 32

What is the purpose of the semicircular canals? What is the fluid inside called?

Back 32

-important for balance
-three per ear, one oriented in each plane
-endolymph

Front 33

T/F aqueous humor enters venuous circulation?

Back 33

T, secreted near the iris at the base of the eye. travels to the anterior chamber, where it exits and eventually enters the venous blood.

Front 34

Where are taste buds located?
Describe what a taste bud looks like?
Where are the receptors located?

Back 34

-tongue, soft palate, epiglottis
-compromised of 40 epithelial cells, outer surface contains a taste pore (mircovilli/taste hairs protrude)
-receptor for taste on the hairs

Front 35

What happens when smells enter the nasal cavity?

Back 35

-bind to receptors in the cilia
-depolarize olfactory receptors
-axons from olfactory receptors join to form olfactory nerves, nerves project directly to the olfactory bulbs in the base of the brain.