Lecture Exam I

Question 1

Functions of the nervous system

Answer 1

Primary control (responding to stimuli)

Higher functions ( cognitive skills)

Question 2

Neurons

Answer 2

Basic structural unit of the nervous system, the excitable cells that transmit electrical signals

Question 3

Glial cells

Answer 3

Nonexcitable cells that primarily support and protect neurons

Question 4

Types of neurons

Answer 4

Multipolar
Bipolar
Pseudounipolar

Question 5

Sensory neurons

Answer 5

Afferent neurons conduct from somatic and visceral receptors

Pseudounipolar, few bipolar

Question 6

Motor neurons

Answer 6

Efferent neurons conduct motor output

Multipolar

Question 7

Interneuron

Answer 7

Association neurons receive process and store information, 99% of neurons

Question 8

What created the membrane potential in neurons? List three factors that contribute to the negative charge inside the cell

Answer 8

3Na+/2K+ pump
More protein in the cell than out of the cell
Phosphate groups

Question 9

What would happen to a neuron’s ability to conduct a nerve impulse if the resting potential didn’t exist?

Answer 9

The cell would remain inactive, so it would not conduct an impulse

Question 10

Leak and gated channels (three types of gated channels)

Answer 10

a. Chemically gated channels
b. Voltage-gated channels
c. Leak channels

Question 11

Action potential

Answer 11

Localized change in electrical potentional

Question 12

propagation of action potential

Answer 12

Propagates toward neuromuscular junction

Question 13

Describe events in the neuromuscular junction

Answer 13

c. Action potention reaches synaptic knob
i. Calcium channels open
ii. Release neurotransmitter in the synapse
iii. Neurotransmitter for skeletal muscles is always actelycholine
iv. Receptors for muscle are Na+ channels (chemically gated)
v. Na+ enters muscle fiber – triggering contraction of muscle
vi. Acetylcholinesterase residing in the synaptic cleft, enzyme that breaks down Ach molecules

Question 14

All or none principal

Answer 14

If threshold reached, action potential propagated. If threshold is not reached, no action potential propagated.

Question 15

Spatial summation

Answer 15

(axon hillock) release of neurotransmitter from multiple presynaptic neurons.

Question 16

Temporal summation

Answer 16

(axon hillock) repeated release of neurotransmitter at same location.

Question 17

EPSP

Answer 17

inside of neuron becomes more positive (less negative). propagate toward axon hillock Na+ flows into neuron.

Question 18

IPSP

Answer 18

inside of neuron becomes more negative. Propagate towad axon hillock. K+ or Cl- flows into neuron.

Question 19

What is refractory period?

Answer 19

This is the time during which another stiumuls given to the neuron will not lead to a second action potential.

Question 20

Absolute refractory

Answer 20

no amount of stimulus will generate a second action potential

Question 21

Relative refractory

Answer 21

with greater stimulation action potential is possible

Question 22

Absolute refractory physiology

Answer 22

voltage-cated channels opened than closed in inactivated state. Remain closed until potential almost to resting potential.

Question 23

Relative refractory Physiology

Answer 23

neuron hyperpolarized. Voltage-gated channels return to resting state.

Question 24

Satellite cells

Answer 24

surround neuron cell bodies in ganglia. Regulate O2, CO2, nutrient, and neurotransmitter levels around neurons in ganglia, found in peripheral nervous system.

Question 25

Neurolemmocytes: schwann cells

Answer 25

surround axons is PNS, are responsible for myelination of peripheral axons, participate in repair process after injury, found in peripheral nervous system.

Question 26

Oligodendrocytes

Answer 26

myelinate CNS axons, provide structural framework, found in central nervous system.

Question 27

Astrocytes

Answer 27

maintain blood-brain barrier, provide structural support, regulate ion, nutrient, and dissolved gas concentrations, absorb and recycle neurotransmitters, form scar tissue after injury, found in central nervous system.

Question 28

Microglia

Answer 28

remove cell debris, waste, and pathogens by phagocytosis, found in central nervous system.

Question 29

Ependymal cells

Answer 29

line ventricles (brain) and central canal (spinal cord), assist in producing, circulating, and monitoring of cerebrospinal fluid, found in central nervous system.

Question 30

Saltatory and continuous conductions. Compare and contrast

Answer 30

Continuous conduction occurs in neurons with unmyelinated axons whereas saltatory conduction occurs in neurons with myelinated axons. Saltatory conduction is much faster than continuous conduction.

Question 31

What is synapse?

Answer 31

a. Region where axon terminal meets its target cell

Question 32

Types of synapses

Answer 32

Chemical and electrical

Question 33

What type of synapse is the most common in nervous system?

Answer 33

Chemical synapses are most common in the nervous system.

Question 34

Curare binds to the Ach receptor without activating them. What is the effect of curare on the skeletal muscle?

Answer 34

Paralysis; life-threatning (wont be able to breathe)

Question 35

The botulism toxin prevents the release of the neurotransmitter into the synapse. What will be the consequence?

Answer 35

Paralysis

Question 36

Structures of the brain and their main functions.

Answer 36

Brain structure and function (already made flashcards on this question)

Question 37

Brain protection. Name four structures that protect the brain.

Answer 37

a. Cranium provides rigid support
b. Meninges that surround the brain
c. Cerebrospinal fluid cushions
d. Blood-brain barrier (prevents entry of harmful materials.

Question 38

CSF production and flow.

Answer 38

a. Produced by choroid plexus
b. Circulates through
i. Lateral ventricle – third ventricle – aqueduct – fourth ventricle – subarachnoid space – arachnoid villi – drains into Dural venous sinuses

Question 39

A drug that blocks ATP production is introduced into an isolated axon preparation. The axon is then repeatedly stimulated, and recordings are made of the response. What effects would you expect tot observe? How propagation of action potential will be affected? Why?

Answer 39

Sodium pumps and potassium pumps will not be triggered to open or close. The cell will not reach the threshold to propagate a reaction, because the pump will remain unmoved.

Question 40

Reflex: definition, types, components.

Answer 40

Are rapid, preprogrammed, involuntary responses of muscles or glands to a stimulus.
Spinal reflex or cranial reflex, somatic reflex or visceral reflex, monosynaptic reflex or polysynaptic reflex, ipsilateral reflex or contralateral reflex, innate reflex or acquired reflex.
Reflexes including a sensory receptor, an effector, and the neural wiring between.

Question 41

Cerebral cortex: primary, association, and functional areas.

Answer 41

Primary: senses. The abilities to sense something in general or special senses.
Association: putting senses with memories. See a pen know it is a pen etc…
Functional areas: motor responses, acting about the senses sensed from the primary region.

Question 42

22. What is Receptor? Types and function of receptors.

Answer 42

a. Structures specialized to respond to changes in the environment.
b. By modality: Nociceptors, Thermoreceptors, Mechanoreceptors, Chemoreceptors.

Question 43

Spinal cord: organization of white and gray matter. What is found within white matter? What is found in the ventral horns of spinal cord? What is found in the dorsal horns of spinal cord?

Answer 43

White matter: posterior funiculus, lateral funiculus, white commissure, anterior funiculus.
Ventral horns: cell bodies of motor neurons
Dorsal horn: sensory nuclei that receive and process incoming somatosensory information.

Question 44

24. Spinal nerves: how many pairs, type (all mixed!) What are the components of spinal nerve? What is found within ventral root? What is found within dorsal root? what is found within dorsal root ganglion? What is ventral ramus? What is dorsal ramus?

Answer 44

31 pairs of spinal nerves
Components of spinal nerve: dorsal root, ventral root, dorsal root ganglion, spinal nerve, posterior ramus, anterior ramus
Ventral root: contains axons of motor neurons.
Dorsal root: contains axons of sensory neurons.
Dorsal root ganglion: collection of neuronal cell bodies
The ventral ramus is the larger portion and is in the anterior and lateral trunks, upper and lower limbs.
The dorsal ramus is the smaller portion and is in deep muscles of back and skin of back.