Module 3 - phys

Question 1

The nervous system has three overlapping functions. Name them.

Answer 1

Sensory input - information gathered by sensory receptors about internal and external changes
Integration - processing and interpretation of sensory input
Motor output - activation of EFFECTOR organs (muscles and glands) produces a response.

Question 2

Name 4 general functions of CNS

Answer 2

cognition, speech, conscious, coordination and planning, movement, motor function, sensory functions

Question 3

CNS is composed of what 2 things?

Answer 3

Brain and spinal cord

Question 4

Name the components of the PNS.

Answer 4

autonomic -> sympathetic and parasympathetic

Somatic -> sensory and motor

Question 5

What part of the body do meninges cover?

Answer 5

spinal cord

Question 6

Explain white and gray matter

Answer 6

White matter -> conduction tracts
Gray matter -> dorsal (posterior) horns – sensory tracts
Anterior (ventral) horns – motor horns

Question 7

Name and explain the two functional divisions of the PNS

Answer 7

1. Sensory (afferent) (goes TOWARDS CNS)
   a. Somatic Sensory fibers: convey impulses from skin, skeletal muscles, and joints to CNS
   b. Visceral sensory fibers: convey impulses from visceral to CNS
2. Motor (efferent) – transmits impulses FROM CNS to effector organs (muscles and glands)
   a. Somatic nervous system (to skeletal muscles)
   b. Autonomic nervous system (to smooth and cardiac muscles, and glands)

Question 8

T/F

Somatic is involuntary and autonomic is voluntary.

Answer 8

False.
Somatic Nervous System – voluntary, under conscious control of skeletal muscles – from CNS to skeletal muscle
Autonomic – visceral motor fibers, regulates smooth muscle, cardiac muscle, and glands
- involuntary

Question 9

Which one of the following is NOT one of the four neuroglia

1. Astrocytes
2. Microglial
3. Ependymal
4. Oligodendrocytes
5. Macroglial

Answer 9

5. Macroglial

Question 10

Which neuroglia allows for exchange between capillaries and neurons (blood brain barrier), and also control the chemical environment.

Answer 10

Astrocytes

Question 11

Which neuroglia forms an insulating myelin sheath?

1. Astrocytes
2. Microglial
3. Ependymal
4. Oligodendrocytes

Answer 11

4. Oligodendrocytes

Question 12

Which neuroglia initiate inflammation and migrate toward injured neurons?

1. Astrocytes
2. Microglial
3. Ependymal
4. Oligodendrocytes

Answer 12

2. Microglial

Question 13

Which neuroglia line central cavities of the brain and spinal column and form a permeable barrier between CSF in cavities and tissue fluid bathing in CNS cells?

1. Astrocytes
2. Microglial
3. Ependymal
4. Oligodendrocytes

Answer 13

3. Ependymal

Question 14

Name the 2 major neuroglia of PNS and explain their functions.

Answer 14

1. Satellite cells – surround neuron cell bodies in PNS, function similar to astrocytes in CNS
2. Schwann cells (neurolemmocytes) – surround all peripheral nerve fibers, form insulating myelin sheaths in thicker nerve fibers (similar function as oligodendrocytes), vital to regeneration of damaged peripheral nerve fibers - guide severed axons of neurons to reconnect if you have nerve injury

Question 15

What generates electrical impulses and transmits those impulses rapidly down its length?

Answer 15

Axon

Question 16

What are the functions of the myelin sheath?

Answer 16

To protect and electrically insulate axon & increase speed of nerve impulse transmission

Question 17

What are the structural classifications of neurons?

Answer 17

1. Multipolar – three or more processes (1 axon, others dendrites) – most common, major neuron type in CNS – lots of processes (information out to muscles)
2. Bipolar – two processes (1 axon, 1 dendrite) – rare (ex. Retina, olfactory mucosa) – good for moving information but not process.
3. Unipolar – one T-like process (2 axons) – long slender body with axons on each side and cell body in middle)- aka psuedounipolar
   - peripheral (distal) process: associated with sensory receptors
   - Proximal (central) process: enters CNS

Question 18

What are the classifications of neurons? (3)

Answer 18

1. Sensory – transmit impulses from sensory receptors toward CNS, almost all are unipolar, cell bodies located in ganglia in PNS
2. Motor – carry impulses FROM CNS to effectors
   - multipolar, most cell bodies are located in CNS (except some autonomic neurons)
3. Interneurons – aka association neurons – between motor and sensory neurons, shuttle signals through CNS pathways, most entirely within CNS, 99% of body’s neurons are interneurons!

Question 19

At rest, is it more negative or positive inside of the cell?

Answer 19

Negative. It will change due to a stimulus.

Question 20

The relationship of voltage, current, and resistance is which law?
Current (I) = voltage (V)/resistance (R)

Answer 20

Ohm’s law

Question 21

T/F

Current is directly proportional to voltage

Answer 21

True

Question 22

T/F

Current is inversely proportional to resistance

Answer 22

True

Question 23

T/F

There are 3 types of ion channels.

Answer 23

False.

2 main types: leakage (non-gated) and gated

Question 24

Name the 3 gated ion channels

Answer 24

chemically gated, voltage-gated, and mechanically gated

Question 25

Match: A) Voltage-gated B) Mechanically gated C) Chemically gated (ligand-gated) 1. Only open with binding of specific chemical (ex neurotransmitter) 2. open and close in response to changes in membrane potential 3. open and close in response to physical deformation of receptors (ex sensory receptors) – ex pressure and vibration

Answer 25

1. C 2. A 3. B

Question 26

Use the words given to complete these sentences. ICF, ECF, K+ _____ has more Na+ - balanced by Cl- ______ has more K+, balanced by negatively charged proteins _____ plays most important role in resting membrane potential!

Answer 26

ECF – more Na+ - balanced by Cl- ICF – more K+, balanced by negatively charged proteins K+ plays the most important role in resting membrane potential

Question 27

1 ATP is needed to pump ____ sodium out, and ____ potassium in.

Answer 27

3 sodium, 1 potassium

Question 28

Name these types of signals: 1. incoming signals operating over short distances 2. long-distance signals of axons

Answer 28

1. Graded potentials | 2. Action potentials

Question 29

What is it called when there is a decrease in membrane potential ( when it moves toward zero and above) and the inside of the membrane becomes LESS NEGATIVE than resting membrane potential – probability of producing impulses increases

Answer 29

Depolarization

Question 30

What is it called when there is an increase in membrane potential (away from zero) and the inside of membrane becomes MORE NEGATIVE than resting membrane potential - probability of producing impulse decreases

Answer 30

Hyperpolarization

Question 31

Which type of signal dissipates over time and which does not?

Answer 31

Graded dissipates, action potentials do not

Question 32

Name the four main steps of action potential.

Answer 32

1. Resting state: All gated Na+ and K+ channels are closed 2. Depolarization: Na+ channels open 3. Repolarization: Na+ channels are inactivating, and K+ channels open 4. Hyperpolarization: Some K+ channels remain open, and Na+ channels reset