Study Guide

Question 1

know the three functional properties of myelin

Answer 1

1: provides protective insulation over nerve cell

2: It allows the electrical impulses to travel quickly between neurons

3: It maintains the strength of the signals down the axon

Question 2

What are the names of the glial cells that act as the myelin sheath in the CNS and PNS

Answer 2

1. Schwann cells – wrap around axons of neurons in the peripheral nervous system to form myelin
2. Oligodendrocytes. – their dendrites/extensions wrap around axons of neurons in the central nervous
   system (CNS) to form myelin

Question 3

For Schwann cells, what is the difference between a neurilemma and myelin?

Answer 3

Neurolemma is the outermost layer of nerve fibers in the peripheral nervous system.

Mylen- a fatty substance that surrounds and insulates axons

Question 4

Neural Conduction:
1. For each of the following phases of action potential, know how voltage is changing,
what cations are moving during each phase, and what direction those cations are
moving (intracellularly or extracellularly)
i. Depolarization
ii. Repolarization
iii. Hyperpolarization

Answer 4

1. Depolarization – Sodium moving intracellularly. Causes depolarization to move from (-70 mV) (+30 mV).
2. Repolarization – Switching back to negative intracellular. sodium channels close and potassium (K+) channels open resulting in potassium leaving the cell. Causing positive influx of intracellular charge
3. Hyperpolarization – Intracellular space temporarily becomes more negative than resting membrane potential. Potassium channels are slow to close allowing excessive K+ to leave
4. Results in the intracellular voltage temporarily becoming more negative than RMP

Question 5

Arrange the meninges layers from most outer (closest to scalp) to most inner (closest to brain).

Answer 5

ESAP

Subdural Mater: contains veins carrying blood and
metabolic waste out of the brain

Arachnoid: contains the subarachnoid space which
contains cerebrospinal fluid

Pia Mater: Contains arteries supplying oxygen and
nutrients to the brain

Question 6

What does “Meninges” translate to?

Answer 6

Membrane

Question 7

What is primary function of Broca’s area?

Answer 7

Coordination of tongue, soft palate, and larynx for speech (frontal)

Question 8

Which lobe is associated with receiving/interpreting sounds and smells?

Answer 8

Temporal Lobe

Question 9

What form does transport take in the blood-brain barrier?

Answer 9

Transcellular

Question 10

Why is the blood-brain barrier restrictive? (Select all that apply).

Answer 10

Pericytes: the end-feet of astrocytes envelope the
blood cells reducing “leaking” of materials between
the blood and brain

Astrocytes: Cells that sparsely line the blood vessel.
Pericytes have contractile proteins that pull
endothelial cells together thereby bringing them into
closer proximity

Tight Junctions: Intercellular adhesion molecules
(similar to buttons for a shirt) that reduce paracellular
transport

Question 11

What is the difference between continuous and saltatory conduction?

Answer 11

Continuous conduction occurs in neurons with unmyelinated axons whereas saltatory conduction occurs in neurons with myelinated axons.

saltatory (“leaping”) conduction – Axons are covered by
myelin (discussed next session) causing the depolarization
wave to “leap” down the axon rather than spread like a
wave

Question 12

What is the major functional difference between the parasympathetic and sympathetic nervous systems?

Answer 12

PNS- Rest and digest
SNS- Fight of flight

Question 13

DAP

Answer 13

1: Dura mater: contains veins carrying blood and metabolic waste out of the brain.

2: Arachnoid – contains the subarachnoid space which
contains cerebrospinal fluid (CSF)
Arachnoid granulations – allows CSF to diffuse into
the dura mater space (sinus)
This will allow cerebral waste to be transported to the
circulatory system to be filtered

3: Pia mater – Contains arteries supplying oxygen and
nutrients to the brain (formation of CSF)

Question 14

The cerebrospinal fluid is produced from selective filtration of blood (plasma) circulating to the
brain

Answer 14

located between the arachnoid and pia mater meninge

what primary substances are removed from the blood to create CSF

Question 15

What is the common transport mechanism at the blood brain barrier (how do substances cross the BBB; paracellularly or transcellularly)?

Answer 15

transcellular transport is more common
at the capillary level, blood exchanges
nutrients and wastes with surrounding tissues

Question 16

What is unique about the BBB that is not found in regular capillary beds around the body?

Answer 16

1. Astrocytes – the end-feet of astrocytes envelope the
   blood cells reducing “leaking” of materials between
   the blood and brain
2. Pericytes – Cells that sparsely line the blood vessel.
   Pericytes have contractile proteins that pull endothelial cells together thereby bringing them into closer proximity
3. Tight Junctions – Intercellular adhesion molecules (similar to buttons for a shirt) that reduce paracellular
   transport

Question 17

What molecular groups can be added to make a substance more lipophilic?

Answer 17

CAM
1. Carboxyl groups (COO, COOH),

2. acetyl groups (C2H3O)
3. methyl groups (CH3)

Question 18

4 major divisions of the brain and their respective functions.

Answer 18

1. Cerebrum
2. Diencephalon
3. Cerebellum
4. Brain Stem

Question 19

Cerebrum

Answer 19

Frontal lobe:
1. Primary Motor Area – Neurons that initiate conduction and contraction of skeletal muscles
2. Prefrontal Cortex – involved in memory, decision-making/problem solving, and conscious thought.
1. Also contains Broca’s area, or motor speech area. Control of tongue, larynx, and soft palate coordination to form complex, specific sounds (language, speech)

Parietal:
receives messages from sensory/afferent neurons
( Primary Somatosensory Area – Receives sensory information (touch, pain, etc.).
 Somatosensory association area – combines sensory information with memory to help
determine what an object is by touch alone.

Temporal: Temporal Lobe is mainly associated with receiving and interpreting sounds and
smells

Occipital: is mainly associated with receiving and interpreting sight/vision

The cerebellum helps maintain coordination, balance, and positioning.

The medulla oblongata in the brain stem controls the homeostasis of blood gases.

Question 20

(Diencephalon) thalamus

Answer 20

direct sensory information to
the correct lobes of the cerebrum

Question 20

(Diencephalon) hypothalamus

Answer 20

regulates negative
feedback control mechanisms (body
temperature, food intake, water balance)

Question 21

The Brain Stem

Answer 21

The Brain Stem is composed of three distinct
regions:
1. The Midbrain
2. The Pons
3. The Medulla Oblongata

Question 22

The Midbrain

Question 23

The Medulla Oblongata

Answer 23

MO is responsible for the automatic control of
blood gases (i.e., O2 and CO2)
 The respiratory center (respiratory muscle control)
The cardiac center (heart rate and strength control)
 Vasomotor center (control of smooth muscles in blood
vessels [vasodilation and vasoconstriction)

Question 24

The Pons

Question 25

5. Widespread Networks
   a. Be familiar with the major features of each of the three widespread networks
   i. Example: Which network is responsible for alertness
6. What are the different types of stroke and the predominant differences of each?

Answer 25

The Limbic System
Basal Nuclei
Reticular Formation

Question 26

WSN: The Limbic System

Answer 26

The limbic system controls behavioral and emotional responses.
1. Cerebrum – Cognitive decision making
2. Diencephalon (hippocampus) – Emotional responses

Question 27

Basal Nuclei

Answer 27

A group of structures distributed in several areas of the brain
 Primary functions:
1. Motor control (coordination and executive action)
2. Motor learning
3. Behavior
4. Emotions
 Part of these basal nuclei are responsible for synthesizing
dopamine.
 Damage or altered activity of the Basal Nuclei has been associated
with addiction, Parkinson’s disease, and Huntington’s disease.

Question 28

Reticular Formation

Answer 28

A formation within the brain stem, this feature is responsible
for
1. Sends impulses to the cerebral cortex to keep us awake and
active
2. Screens out unnecessary sensory input
1. Makes us more aware of novel stimuli
1. “Cocktail party effect”
3. This area of the brain is inhibited by “sleep centers” in our brain
so that we can rest.