The Nervous System Flashcards Preview

MCAT Self Study > The Nervous System > Flashcards

Flashcards in The Nervous System Deck (44):
1

What is included in the Central Nervous System?

Brain and spinal cord.

2

What is included in the Peripheral Nervous System?

Everything that isn't the brain and spinal cord.

3

Contrast spatial and temporal summation of neurons.

Spatial summation occurs when the signals are received at the same time.

Temporal summation occurs when the signals are received one after another.

4

Describe the concentration of Na and K around/ inside the cell.

Sodium (Na) is highly concentrated outside the cell.
Potassium (K) is highly concentrated inside the cell.

5

What is the resting membrane potential for neurons?

-70mV, the number isn't important but realize that it is negative compared to the outside. The membrane is much more permeable to potassium than it is to sodium. The K+ leaves the cell rapidly down its concentration gradient.

6

What does the Na/K do?

Pumps 3 Na out/ pumps 2 K in.

7

What two forces create the equilibrium for the resting membrane potential.

Primary dictated by the diffusion of potassium going out of the cell. Followed by the electrochemical equilibrium of potassium in and out of the cell.

8

Describe the process of depolarization and repolarization

1. In Depolarization: when a signal stronger than the threshold is met, the voltage gated sodium channels open allowing sodium to flood into the cell causing it to be more positive.
2. In repolarization: after a point, the voltage gated sodium channels close which allow the voltage gated potassium channels to open allowing the potassium ions to flood out of the cell- may cause hyperpolarization.
3. Na/K pump seeks to balance back to resting membrane potential.

9

What does "all of nothing" mean?

The signal either allows for a signal or occur, or it doesn't. This also means the amplitude of the action potential is the same for every signal. The frequency increases for increased signals.

10

Contrast absolute and relative refractory period

Absolute refractory occurs during de/repolarization.
Relative refractory occurs during hyperpolarization.

11

Describe what occurs at the synapse

1. The action potential reaches the presynaptic axon terminal and opens voltage gated calcium channels.
2. Calcium floods into the cell which activates the release of neurotransmitters
3. The neurotransmitters are released into the synapse and bind to the post synaptic terminal.
4. Secondary messenger system activates or inhibits a response.

12

What is the function of the microglia?

Macrophages of the nervous system. Fight infections.

13

What is the function of the ependymal cells?

Epithelial cells which circulate the CSP

14

What is the function of astrocytes?

Help support cells in the CNS.

15

What is the function of satellite cells?

Help support cells in the PNS.

16

Compare oligodendrocytes vs schwann cells.

oligodendrocytes produce myelin for CNS
schwann cells produce myelin for PSN.

17

What is saltatory conduction?

Rapid movement of action potential down the axon of the neuron.

18

What is a reflex?

Quick response to a stimuli, doesn't require higher order thinking because it's essentially automatic.

19

Compare and contrast autonomic and somatic nervous system.

They're both part of the peripheral nervous system.
Somatic is voluntary while autonomic is involuntary- smooth muscle, cardiac, and glands.

20

Compare and contrast Parasympathetic and Sympathetic systems

They're both part of the autonomic response. Sympathetic is fight or flight. Parasympathetic is rest and digest.

21

What is acetylcholine used for? What about epinephrine and norepinephrine.

Parasympathetic and somatic, peripheral: acetylcholine
Sympathetic: epinephrine and norepinephrine.

22

What three areas make up the lower brain?

brainstem
cerebellum
diencephalon

23

What areas make up the brainstem & what are their functions?

Medulla: respiratory cardiovascular maintenance center.
Midbrain: rely station for auditory and visual signals.
Pons: communicate motor function between cortex and cerebellum.

24

What is the function of the cerebellum?

Coordinate movement and BALANCE.

25

What makes up the diencephalon?

The thalamus and the hypothalamus.

26

What is the function of the thalamus?

Receives sensory information and relays it to the higher areas in the brain.

27

What is the function of the hypothalamus?

The hypothalamus maintains the body's homeostasis by regulating temperature and water balance. KEY for endocrine system.

28

What areas make up the higher brain?

Cerebrum and Cerebral Cortex

29

What are the four areas of the cerebral cortex?

1. temporal
2. frontal
3. occipital
4. parietal.

30

What is the function of the frontal lobe?

voluntary movement & control of the other lobes. Motor homunculus.

31

What is the function of the parietal lobe?

Sensory homunculus, is able to detect physical stimulus such as temperature, touch, pain.

32

What is the function of the occipital lobe?

the occipital lobe is responsible for visual information.

33

What is the function of the temporal lobe?

Responsible for auditory and olfactory information.

34

What are the three parts of the meninges?

Pia Mater
Arachnoid
Dura Mater

35

What structures are in the hind brain?

Also called the rhombencephalon, the hind brain includes the pons, cerebellum, and the medulla.

36

What is the function of the pons?

Sensory pathway from the cortex to the medulla.

37

What is the function of the midbrain?

Also called the mesencephalon, the midbrain receives sensory information.

Superior Calliculi receives visual information.
Inferior Calliculi receives auditory information.

38

What are the different parts of the hypothalamus?

Anterior Hypothalamus
Lateral Hypothalamus
Ventromedial hypothalamus

39

What is the function of the anterior hypothalamus?

Sexual function. If it is damaged then you may be asexual.

40

What is the function of the lateral hypothalamus?

Controls hunger. If LH is destroyed then you might Lack Hunger.

41

What is the function of the Ventromedial Hypothalamus?

Satiety. If VMH is destroyed then you might be Very Much Hungry.

42

What is the function of the basal ganglia?

Helps with the movement of smooth muscle.

43

What components does the limbic system have?

The limbic system HAS:
Hippocampus: memory.
Amygdala: aggression.
Septic nuclei: pleasure center.

44

Contrast dominant and nondominant hemispheres

Dominant (usually left) is used for analytical function.
NonDominant (usually right) is used for creativity.