Lecture Exam 1 - Chapter 13 Study Guide

Question 1

What are the protective structures of the spinal cord?

Answer 1

-The Spinal Column -The Meninges -The Cerebrospinal Fluid

Question 2

What are and where are the Meninges?

Answer 2

Connective tissue covering the spinal cord Outer layer = Dura Mater middle layer = web-like Arachnoid Mater inner layer = very thin Pia Mater

Question 3

How many pairs of Spinal Nerves are there?

Answer 3

31

Question 4

How many pairs of cervical nerves are there?

Answer 4

8

Question 5

How many pairs of thoracic nerves are there?

Answer 5

12

Question 6

How many pairs of lumbar nerves are there?

Answer 6

5

Question 7

How many pairs of sacral nerves are there?

Answer 7

5

Question 8

how many pairs of coccygeal nerves are there?

Answer 8

1

Question 9

What are the names of the connective tissue covering the spinal nerves and where are they?

Answer 9

surrounding the nerve: Epineurium Surrounding each fascicle: Perineurium Surrounding individual axons: Endoneurium

Question 10

Where is the cervical plexus (which vertebrae)?

Answer 10

C1-C5

Question 11

Where is the brachial plexus (which vertebae)?

Answer 11

C5-T1

Question 12

Where is the Lumbar Plexus (which vertebrae)?

Answer 12

L1-L4

Question 13

Where is the Sacral Plexus (which vertebrae)?

Answer 13

L4-S4

Question 14

From which plexus does this nerve originate and name the function: Phrenic

Answer 14

Cervical Plexus. Innervates Diaphragm

Question 15

From which plexus does this nerve originate and name the function: Axillary

Answer 15

Brachial Plexus. Innervates the deltoid.

Question 16

From which plexus does this nerve originate and name the function: musculocutaneous

Answer 16

Brachial Plexus. Innervates the anterior upper arm, Biceps Brachii, etc.

Question 17

From which plexus does this nerve originate and name the function: Ulnar

Answer 17

Brachial Plexus. Innervates most of the muscles of the hand, e.g. flexor carpi ulnaris.

Question 18

From which plexus does this nerve originate and name the function: Median

Answer 18

Brachial Plexus. Innervates muscles of the anterior forearm (excluding flexor carpi ulnaris and other muscles supplied by the ulnar nerves) and some muscles of the hand. e.g palmaris longus

Question 19

From which plexus does this nerve originate and name the function: Radial

Answer 19

Brachial Plexus. Innervates muscles of the posterior arm and forearm. e.g. Triceps brachii

Question 20

From which plexus does this nerve originate and name the function: Femoral

Answer 20

Lumbar Plexus. Innervates iliacus, quadriceps femoris, sartorius, pectineus.

Question 21

From which plexus does this nerve originate and name the function: Obturator

Answer 21

Lumbar Plexus. Innervates adductor longus, adductor brevis, and part of adductor magnus, gracilis

Question 22

From which plexus does this nerve originate and name the function: Common Fibular

Answer 22

Sacral Plexus. Innervates fibularis longus muscle, tibialis anterior, extensor digitorum longus

Question 23

From which plexus does this nerve originate and name the function: Pudendal

Answer 23

Sacral Plexus. Innervates muscles of the perineum

Question 24

From which plexus does this nerve originate and name the function: Sciatic

Answer 24

Sacral Plexus. Innervates biceps femoris, semimembranosus,semitendinosus (hamstrings)

Question 25

From which plexus does this nerve originate and name the function: Tibial

Answer 25

Sacral Plexus. Innervates gastrocnemius, soleus, tibialis posterior, flexor digitorum longus, plantaris, flexor hallucis longus

Question 26

What nerves branch off from the Sciatic?

Answer 26

The Tibial and the common fibular

Question 27

Know which brachial nerve is influenced in each of the injuries in Fig 13.8, p. 507: Erb-Duchenne palsy

Answer 27

a.k.a. waiter’s tip position Caused by injury to the superior roots of the brachial plexus

Question 28

Define: Reflex

Answer 28

Rapid, involuntary motor responses to an environmental stimulus detected by sensory receptors.

Question 29

Define: Reflex Arc. Understand the steps in generating a reflex arc and the pathways followed by nerve impulses in the process.

Answer 29

Reflex Arc: The pathway followed by nerve impulses that produce a reflex Five functional components – 1)Sensory Receptor 2)Sensory Neuron 3)Integrating Center 4)Motor Neuron 5)Effector

Question 30

What happens in a stretch reflex?

Answer 30

A stretch reflex causes contraction of a skeletal muscle (the effector) in response to stretching of the muscle. Steps: 1) stretching of muscle stimulates sensory receptors called muscle spindles. 2)muscle spindle gnerates nerve impulses that propaged along a somatic sensory neuron through the posterior root of the spinal nerve into the spinal cord 3) in the integrating center, the sensory neuron activated a motor neuron in the anterior gray horn 4)if the excitation is strong enough, a nerve impulse propagates doen the motor neuron to the effector 5) ACh is released by the motor neuron at the NMJ, triggering a muscle action potential, so that the muscle contracts, relieving the stretching.

Question 31

What happens in a tendon reflex?

Answer 31

Tendon reflex: operates as a feedback mechanism to control muscle tension by causing muscle relaxation before muscle force becomes so great that tendons might be torn. Steps: 1)When tension to a tendon increases sensory receptors (called tendon organs) are stimulated 2)nerve impulses propagate to the spinal cord along a sensory neuron 3)within the integrating center, the sensory neuron activates an inhibitory interneuron that synapses with a motor neuron 4)the inhibitory neurotransmitter inhibits the motor neuron, which then generates fewer nerve impulses 5)the muscle relaxes and relieves excess tension

Question 32

What happens in a withdrawal (flexor) reflex?

Answer 32

Happens when, for example, you step on a tack. Steps 1) stepping on tack stimulates dendrites of a pain-sensitive neuron 2)sensory neuron sends impulse to spinal cord 3) within integrating center, sensory neuron activates interneurons that extend to several spinal cord segments 4)the interneurons activate motor neurons, which generate nerve impulses 5)ACh released by the motor neurons causes the flexor muscles in the thigh to contract, withdrawing the leg from the tack.

Question 33

What happens in a crossed extensor reflex?

Answer 33

this reflex helps you maintain your balance while withdrawing your leg after stepping on the tack. Steps: 1)Steping on the tack stimulates sensory neurons in the right foot 2) sensory neuron sends nerve impulses to the spinal cord 3)in the integrating center, the sensory neuron activates several interneurons that synapse with motor neurons on the left side of the spinal cord in several spinal cord segments. 4)The interneurons excite motor neurons that innervate extensor muscles. 5)ACh released by motor neurons causes the extensor muscles in the thigh of the unstimulates left limb to contract, producing the extension of the left leg, so that it can take your weight.

Question 34

Why does your doctor test your patellar reflex?

Answer 34

to test for damange to the sensory or motor nerves supplying the muscle or the integrating centers in the 2nd, 3rd, or 4th lumbar segments of the spinal cord. This reflex is often absent in people with chronic diabetes mellitus or neurosyphilis.

Question 35

Know the traumatic injuries information on P. 489: Monoplegia

Answer 35

paralysis of one limb only

Question 36

Know which brachial nerve is influenced in each of the injuries in Fig 13.8, p. 507: Wrist drop

Answer 36

caused by radial nerve injury, sensory loss minimal

Question 37

Know which brachial nerve is influenced in each of the injuries in Fig 13.8, p. 507: Median Nerve palsy

Answer 37

median nerve injury. numbness, tingling, and pain in the palm and fingers. inability to pronate the forearm and flex the distal inerphalangeal joints of the 2nd and 3rd digits. Thumb movements are weak, and wrist flexion is weak and accompanied by adduction.

Question 38

Know which brachial nerve is influenced in each of the injuries in Fig 13.8, p. 507: ulnar nerve palsy

Answer 38

ulnar nerve injury. inability to abduct or adduct the fingers, atrophy of the interosseous muscles of the hand, hyperextension of the metacarpophalangeal joints, and flexion of the interphalangeal joints, a condition called clawhand.

Question 39

Know which brachial nerve is influenced in each of the injuries in Fig 13.8, p. 507: winged scapula

Answer 39

long thoracic nerve injury, resulting in paralysis of the serratus anterior muscle.

Question 40

Know the traumatic injuries information on P. 489: Diplegia

Answer 40

paralysis of both upper limbs or both lower limbs

Question 41

Know the traumatic injuries information on P. 489: Paraplegia

Answer 41

paralysis of both lower limbs

Question 42

Know the traumatic injuries information on P. 489: hemiplegia

Answer 42

paralysis of the upper limb, trunk, and lower lib on one side of the body

Question 43

Know the traumatic injuries information on P. 489: quadriplegia

Answer 43

paralysis of all four limbs

Question 44

Know the traumatic injuries information on P. 489: complete transection

Answer 44

the spinal cord is severed from one side to the other, cutting all sensory and motor tracts. results in a loss of all sensations and voluntary movement below the level of the transection.

Question 45

Know the traumatic injuries information on P. 489: Hemisection

Answer 45

partial transection of the cord on either the right or left side.

Question 46

Know the traumatic injuries information on P. 489: Spinal Shock

Answer 46

happens following complete transection and to varying degrees after hemisection. Spinal shock is an immediate response to spinal cord injury characterized by areflexia, loss of reflex function.

Question 47

Know the traumatic injuries information on P. 489: Areflexia

Answer 47

loss of reflex function