Study guide midterm 1

Question 1

Terminal button

Answer 1

Site of synapse for an axon. Where it releases it’s neurotransmitter to either a dendrite, soma, or axon of another/multiple neuron(s).

Question 2

Types of neurons and roles

Answer 2

Multi- most common in the CNS. Motor.
Bipolar- retina. Eyes, ears and nose.
Unipolar- Most common in the PNS. Main sensory neuron. Dendrite and axon “share” a process.

Question 3

Peripheral nervous system

Answer 3

Cranial nerves (except 1 and 2 because they are covered with meninges), axons of some spinal nerves, peripheral nerves, and neuromuscular junctions.

Question 4

Nerve layers and connective tissues

Answer 4

Endoneurium covers neuron/fiber. Bundle of this creates fascicle. Fascicle is covered by perineurium. Bundles of fascicles are covered by epineurium and also include fat, blood vessels and schwann cells. This is a neuron.

Question 5

Neural injury. What happens to neuron?

Answer 5

Severe damage or immediate fatal injury= little change in cell morphology. Quickly disintegrates.

Question 6

Less severe neural injury. What happens?

Answer 6

Swelling in soma, displacement of nucleus, movement of nussl bodies (rER) to the periphery. If cell survives, all will go back to normal. If not, cytoplasm will turn dark and followed by disintegration of all organelles and the cell.

Question 7

Dead neurons are removed from the CNS by ___ and in the PNS by ___

Answer 7

CNS by microglia and in the PNS by macrophages

Question 8

Axon injuries

Answer 8

Axon injuries proximal to the soma are usually more severe for the cell compared to those that are distal. Distal injuries are likely to only affect part of the axon.

Question 9

Pia matter contains

Answer 9

Collagen and elastic fibers. Very delicate layer of the connective tissue.

Question 10

Where does the CNS contain connective tissue?

Answer 10

The meninges and in the outer layer of blood vessels.

Question 11

3 types of hematomas

Answer 11

1. Epidural. Above the dura. Shearing of artery. Commonly due to the middle meningeal artery in the pterion. Since it is an artery, there is high pressure and progresses quickly.
2. Subdural. Underneath the dura. Shearing of vein. Commonly the emissary veins that pass through the skull. Less pressure, less progressive.
3. Subarachanoid. Rare and usually due to cerebral aneurysm that has ruptured. Blood mixes with CSF and will raise pressure.

Question 12

Visceral nervous system

Answer 12

Autonomic NS

Question 13

How memories are formed

Answer 13

Afferent signals from all over the body enter the CNS and are organized there in such a way that yields our perceptions (correlations of signals) and these perceptions are stored in the CNS as memories.

Question 14

Somatic efferent and afferent

Visceral efferent and afferent

Answer 14

Somatic afferent- General senses and special senses such as vision, hearing.
Somatic efferent- Innervation to skeletal muscles

Visceral afferent- Receptors from glands, blood vessels, viscera/internal organs and other special senses such as smell and taste.

Question 15

Rami comunications

Answer 15

Neural fibers of the sympathetic division of the autonomic NS.

Question 16

Sympathetic ganglion

Answer 16

Carries sympathetic division of ANS and PNS. Carries some components of the somatic division of the PNS

Question 17

Cortical magnification

Answer 17

Areas with smaller, densely packed receptive fields. hands, feet, lips.

Question 18

Purpose of some receptive fields being excitatory and the surrounding being inhibitory

Answer 18

Allows for better resolution

some receptors in the retina have the opposite configuration

Question 19

Dermatomes

Answer 19

Each spinal nerve carries somatic sensory information from a specific area of the skin on the surface of the body. A dermatome is that area of skin supplied by a single spinal cord level. There is slight overlapping, but mostly defined. Can be used to localize lesions to a specific spinal nerve.

Question 20

Myotomes

Answer 20

portion of the skeletal muscle innervated by a single spinal cord level. More difficult to isolate to a single spinal nerve because skeletal muscles are usually innervated by nerves derived from more than one spinal cord.

Question 21

Muscles that move the 
1. Shoulder
2. elbow
3. hands
are innervated by which spinal nerves?

Answer 21

Shoulder- C5 and 6
Elbow- C6 and 7
Hands- C8 and T1

Question 22

What spinal cord region is a nerve plexus not present?

Answer 22

The thoracic region does not have a nerve plexus.

Question 23

Spinal nerve plexus

Answer 23

Extensive branching and cross joining of neighboring anterior rami.

Question 24

Key somatic plexuses

Answer 24

1. Cervical plexus to the neck and back of head. Formed from anterior rami of C1-C4.
2. Brachial plexus formed from anterior rami of C5 to T1. Serves the chest, shoulder, arms, and hands.
   - Superior portion injured when head and neck are pulled away from arm. “Waiter tip” position. Hand still has muscle movement.
   - Inferior portion of the plexus injured from pulling arm. Innervation to hand is compromised. Claw grip presentation. Hand still has innervation.

Question 25

When do pt’s demonstrate waiter tip position and claw grip position?

Answer 25

Waiter tip- when they damage superior portion of the brachial plexus.
Claw grip- When they damage the inferior portion of the brachial plexus. Arm and shoulder still have innervation.

Question 26

What part of the body is not considered a dermatome

Answer 26

C1- motor only