Nervous System Anatomy & Physiology

Question 1

What two major structures make up the CNS?

Answer 1

brain and spinal cord

Question 2

What one type of structure makes up the PNS?

Answer 2

All the nerves that connect the rest of your body to the brain and spinal cord

Question 3

3 main structural divisions of the brain

Answer 3

Cerebrum, cerebellum, brainstem

Question 4

Major functions of the cerebrum

Answer 4

Responsible for higher-level functions like thought and memory, and complex processing of sensory and motor information

Question 5

Major functions of the cerebellum

Answer 5

Regulates motor control

Question 6

Major functions of the brainstem

Answer 6

Controls many vital functions (e.g. cardiac and respiratory)

Question 7

Gray matter

Answer 7

Made up of neuron cell bodies (dorsal and ventral horns)

Question 8

White matter

Answer 8

Made up of myelinated axons

Question 9

Tracts

Answer 9

Groups of axons running up and down the spinal cord

Question 10

Ascending tracts

Answer 10

carry sensory information from the body (skin, muscles, organs, etc) to the brain (AFFERENT PATHWAYS)

Question 11

Descending tracts

Answer 11

carry motor signals from the brain to the body (EFFERENT PATHWAYS)

Question 12

What tough membrane protects the brain and spinal cord?

Answer 12

Meninges

Question 13

What tough membrane protects the nerves?

Answer 13

Epineurium, perineurium and endoneurium

Question 14

What are the two main functions of CSF?

Answer 14

1. Provides cushioning and support
2. Clears waste out of the CNS

Question 15

What are the two main divisions of the PNS?

Answer 15

Somatic and autonomic

Question 16

Major functions of the somatic sensory system?

Answer 16

Collects information about pressure, temperature, proprioception and pain

Question 17

Major functions of the somatic motor system

Answer 17

Controls all of the voluntary muscle movements in the body

Question 18

Somatic nervous system

Answer 18

Nerves that innervate skin, joints and voluntary muscles

Question 19

Autonomic nervous system

Answer 19

The nerves that control involuntary functions (e.g. blood pressure, intestinal function, gland secretions); consists of sensory and motor elements

Question 20

What are the major 2 categories of cells in the nervous system?

Answer 20

Neurons and glial cells

Question 21

Function of neurons

Answer 21

They process and transmit information electrochemically

Question 22

Functions of glial cells

Answer 22

Considered support cells

Question 23

4 structural elements that make neuronal cells different from most non-nervous system cells (by allowing directional flow of information)

Answer 23

1. Dendrites (receive information)
2. Axons (sends information)
3. Specialized cell membrane that allows them to be electrically excitable
4. Synaptic terminals (release neurotransmitters)

Question 24

Name 4 types of glial cells

Answer 24

1. Astrocytes
2. Myelinating cells
3. Microglia
4. Ependymal cells

Question 25

Functions of astrocytes

Answer 25

Regulation of chemical content of the CNS extracellular space (by taking up or releasing ions, nutrients, neurotransmitters, etc. as needed)

Question 26

2 types of myelinating cells and where they’re found

Answer 26

Oligodendrocytes (in the CNS)
Schwann cells (in the PNS)

Question 27

Functions of Myelinating cells

Answer 27

Wrap around neuron axons in many layers, providing electrical insulation

Question 28

Which two types of cells make white matter white?

Answer 28

Schwann cells and oligodendrocytes

Question 29

Functions of microglia

Answer 29

The brain’s main form of immune defense; dispose of damaged neurons, infectious agents and other debris in the CNS; shape changes based on location and current level of activity

Question 30

Functions of ependymal cells

Answer 30

1. Line the fluid-filled cavities of the brain (ventricles) and spinal cord (central canal)
2. Produce and reabsorb CSF and move it around by beating their cilia
3. Makes up choroid plexus, a structure that produces most of the CSF in the body

Question 31

Define resting membrane potential and if negative or positively charged

Answer 31

1. The charge inside of a neuron at rest
2. Negatively charge (-70mV)

Question 32

Inhibitory synapse

Answer 32

Synapses where the neurotransmitter binding to the receptor causes postsynaptic cell to become more negative

Question 33

Excitatory synapse

Answer 33

Synapses where the neurotransmitter binding to the receptor causes postsynaptic cell to become more positive

Question 34

What type of ion flow is responsible for bringing the membrane potential from the threshold value to a positive value?

Answer 34

When the membrane potential reaches -55mV, voltage-gated sodium ion channels open, allowing sodium ions to flow into the cell

Question 35

What happens at the action potential peak?

Answer 35

Voltage-gated sodium channels close, and voltage gated potassium ions open (allowing potassium to flow out of the cell)

Question 36

What happens once an action potential reaches the synaptic terminal?

Answer 36

Voltage-gated calcium channels open, allowing calcium ions to flow in which causes neurotransmitters to be released into the synaptic cleft

Question 37

Two main functions of myelin sheaths

Answer 37

electrically insulates and increases the speed of the action potential

Question 38

Saltatory conduction

Answer 38

Action potential jumps from node to node since no voltage-gated channels live under the myelin sheaths; makes the AP faster