Nervous System Overview

Question 1

Ganglion (pl: ganglia)

Answer 1

Bundle of neural cell bodies found in the PNS

Question 2

Nucleus

Answer 2

Collection of cell bodies in CNS

Question 3

Nerve

Answer 3

A bundle of neuronal axons

Question 4

Afferent is interchangeable with

Answer 4

Sensory

Question 5

Efferent is interchangeable with

Answer 5

Motor

Question 6

Sensory is interchangeable with

Answer 6

afferent

Question 7

Motor is interchangeable with

Answer 7

Efferent

Question 8

Anatomical direction of the brain

Answer 8

Rostral (anterior) - towards nose

Caudal (posterior)- Towards tail

Dorsal- top

ventral- bottom

Think: horse

Question 9

What do afferent (sensory) neurons do

Answer 9

Receive and transmit information from the enviroment to the CNS

Question 10

What do efferent (motor) neurons do?

Answer 10

Transit information from the CNS to the PNS to elicit a response

Question 11

Main parts of the CNS and PNS

Answer 11

CNS: Brain and spinal cord

PNS: Cranial neres (except not CN 1 or 2), spinal nerves (motor/efferent), peripheral nerves(mixture of motor, sensory and autonomic), and neuromuscular junctions.

Question 12

Divisions of the PNS

Answer 12

Somatic: Conscious/voluntary

Autonomic: Involuntary

• Sympathetic (fight or flight)
• Parasympathetic (rest and digest)

Question 13

Effector in somatic (voluntary of PNS) nervous system

Answer 13

Skeletal mucles

Question 14

Effectors of the involuntary/autonomic part of the PNS

Answer 14

Smooth muscles, glands, cardiac, adipocytes

Question 15

Glial cells/neuroglia

Answer 15

Support neurons and their functions (CNS)

• Astrocytes
• Microglia
• ependymal
• oligodendrocytes

Question 16

What cells in the PNS produce myelin

Answer 16

Schwann

Question 17

What cells in the CNS produce myelin

Answer 17

Oligodendrocytes

Question 18

Another name for body of a neuron

Answer 18

perikaryon, soma

Question 19

Neurite

Answer 19

Dendrite + axon

Question 20

Axon transport (2 main types)

Answer 20

Anterograde- moving from soma to axon terminal. Traveling in the same direction as the signal.

1. Rapid anterograde: Rapid. Quick. Fed ex. Utilizes protein kinesin, which transports secretory vesicles likely filled with neurotransmitter from the soma and/or mitochondria by the microtubules. Travels 2-4 cm a day. Requires ATP.
2. Slow transport. Another type of anterograde, but moves passively through the axon’s plasma. Slow, snailmail. No ATP or energy required.

Retrograde: Moving from axon terminal to soma. Travels in the oppsite direction of the signal. Dynein is the transport protein that carries worn-out organnels on microtubules. Requires ATP.

Question 21

Which is more common- chemical or electrical synapse

Answer 21

Chemical synapse is more common. Electrical synapses commonly occur in the brain.

Question 22

3 types of neurons

Answer 22

Classification based on the number of neurites (axons and dendrites) a cell has

1. Multipolar neuron:
   - Numerous dendrites
   - Most common type in the CNS
   - Motor, integrator, intermediate
2. Bipolar neuron:
   - Single dendrite from ell body.
   - Sensory receptors
   - Sight, smell and vestiular
3. Pseudo-unipolar neuron:
   - Single dendrite/axon arises from common stem off body cell
   - Most common type in PNS
   - Primary sensory neuron

Question 23

What type of neuron is most common in the CNS

Answer 23

Multipolar neuron

Question 24

What type of neuron is most common in the PNS

Answer 24

Pseudo-unipolar (unipolar) neuron

Question 25

Neuron classifiations based on size

Answer 25

1. Golgi type 1: Long axons (vast majority of neurons are golgi type 1. They can either be sensory/afferent or motor/efferent). 2. Golgi type 2: Very short axons. Ex: interneurons.

Question 26

Reflex arc

Answer 26

Receptor (organ) --\> afferent/sensory neuron --\> interneuron ---\> efferent/motor neuron ---\> effector organ (skeletal muscle for somatic or gland/smooth muscle for autonomic/involuntary NS)

Question 27

Astrocytes

Answer 27

Neuroglia found in the CNS. The most abundant and largest glial cell. Many functions include structural support for neurons, metabolic support (uptake excess K+ and renew neurotransmitters), some contribution to the blood brain barrier, and promote myelination activity of oligodendryocytes. Can also modulate local blood flow by it's foot process coming in contact with gap junctions

Question 28

Micoglia

Answer 28

2nd most common in the CNS. Derrived from mesenchyme. Immunological function- phagocytic role, response to tissue damange, inflammation and infection. (Schwann cells in the PNS have a phagocytic role too)

Question 29

Ependymal cells

Answer 29

Epithelial type cells with tight junctions and typically ciliated. Line ventricles and central canal of spinal cord. Aid in production and moement of CSF.

Question 30

\_\_\_ is made up of modified ependymal cells

Answer 30

Choroid plexus. Where CSF is made.

Question 31

Oligodendrocytes

Answer 31

Myelination of the CNS. It wraps around multiple axons many times using extensions from one cell body. Very efficient.

Question 32

Schwann cells

Answer 32

Myelinating cells found in the PNS. It's cell body can wrap around a portion of an axon multiple times, but thats it. It only comes in contact with one axon. Exception: schwann cells can "encapsulate" many tiny tiny axons. However, this is technaiicaly not a form of myelination, since the myelin doesn't "wrap," it only encapsulates. Technically not a glial cell, since it isn't found in the CNS.

Question 33

White matter

Answer 33

Myelinated axons in the CNS

Question 34

Grey matter

Answer 34

Cell bodies (perikaryon) in the CNS and glial cells.

Question 35

Where is white and grey matter located at in the brain? In the spinal cord?

Answer 35

Brain- white in center, grey on outside. Spinal cord- Grey in center, white on outside.

Question 36

Basic nerve structure from smallest to largest

Answer 36

Fibers/neurons wraped by endoneurium--\> Fasicles wraped by perineurium--\> nerves wraped by epineurium Within the nerve, you have the fasicle bundles, fat, blood vessels, and neuroglia. Endo, peri, and epineurium are all types of connective tissues.

Question 37

Nissle bodies

Answer 37

Rough ER in the neuron. It will degrade if neuron is damanged. Causes neucleus to be pushed to the side. If the injury is mild, the neuron can recover. If not, the neuron will dissinigrate/

Question 38

Meninges and examples

Answer 38

Are dural deflections (dura mater) - Falx cerebelli (cerebral falx) - Tentorium cerebelli

Question 39

Hematomas

Answer 39

Area of blood that collects outside of larger blood vessels. A subdural hemorrhge (ruptured **vein**) is deep to dura and will spread slowly. (bleeding is between arachnoid space and dura mater) An epidural hemorrhage is **arterial bleeding** that will spread quick because pressure in the artery is so high. (bleeding is between dura mater and skull)

Question 40

Weakest part of the skull

Answer 40

Pterion. Where 4 bones on the skull come together, Traction and the middle meningial artery is there. if you shatter the pterion, the middle meningial artery splits and causes an epidural. needs to be drained or too much pressure will be put on the brain and cause death.