Chap 12 Flashcards
1
Q
spinal cord where thicker than the rest called, cervical and lumbar _______.
A
enlargements
2
Q
spinal cord is composed of (4 nerves);
A
- cervical
- thoracic
- lumbar
- sacral
3
Q
spinal cord has _____ pairs of spinal nerves.
A
31 pairs
4
Q
Peripheral Nervous System (PNS) consists of ____ pair of cranial nerves and ____ pair of spinal nerves.
A
12, 31
5
Q
meninges layer from superficial to deep;
A
- epidural space
- dura mater (thickest)
- subdural space (serous fluid)
- arachnoid (thin, wispy) mater
- subarachnoid space (blood vessels & cerebrospinal fluid)
- pia mater (tightly attached to spinal cord)
6
Q
structure of nerves;
A
- delicate connective tissue surrounds a single axon and its schwann cell= endoneurium
- group of axons form= fascicles
- heavier connective tissue surrounds a nerve fascicle= perineurium
- third layer of dense connective tissue surrounds a nerve= epineurium
7
Q
functions of spinal cord;
A
- link between brain and PNS
- integrates information
- responses through reflex
8
Q
5 reflex components;
A
- sensory receptor
- sensory neuron
- interneuron
- motor neuron
- effector organ
9
Q
reflex arc 5 components;
A
1. sensory receptor detects a stimula 2. sensory neuron conducts action potential to the CNS 3. interneuron in the spinal cord, sensory neuron synapses with an interneuron 4. motor neuron interneuron synapse with motor neuron 5. effector organ motor neuron conducts action potential to an effector organ (skeletal muscle)
10
Q
muscle of the hyoid, skin of the neck, posterior portion of the head, the diaphragm are innervated (supplied) by;
A
cervical plexus
11
Q
characteristics of stretch reflexes;
A
- control posture
- does not involve an interneuron(=sensory neurons synapse directly with motor neurons)
12
Q
gamma motor neuron stimulates;
A
contraction of muscle spindles
13
Q
muscle spindle is;
A
sensory receptor of a stretch reflex
14
Q
alpha motor neuron;
A
stimulates muscle contraction
15
Q
characteristics of reflexes;
A
- homeostatic
- can be influenced by higher brain centers
- integrated within the CNS
- produce consistent results
16
Q
stretch reflex cause muscle to;
P.406
A
contract
- control posture
17
Q
Golgi tendon reflex cause muscles to;
A
relax
- inhibition of alpha motor neurons
- happen at tendon; prevents excessive tension to tendons
18
Q
withdrawal reflex event;
A
- pain receptors detect a painful stimulus
- sensory neurons conduct action potentials to the spinal cord
- sensory neuron synapses with an excitatory interneuron
- excitatory interneuron synapses with an alpha motor neuron
- muscle contracts
- a body part is withdrawn from the painful stimulus
19
Q
region of the spinal cord where it tapers to a point;
A
medullaris
20
Q
5 plexus;
P.411
A
- cervical 4
- brachial 5 (C5-T1)
- lumbar 4 (L1-L4)
- sacral 5 (L5-S4)
- coccygeal 2 (S5-Co)
21
Q
Golgi tendon reflex;
P.407
A
- promotes muscle relaxation
- involves an inhibitory interneuron
- inhibits contraction to prevent excessive damage to tendons
22
Q
dura mater
A
thickest layer of the meninges
23
Q
arachnoid mater
A
thin, web-like layer of the meninges
24
Q
pia mater
A
thin layer of meninges bound tightly to the surface of the spinal cord
25
subarachnoid space is filled with;
- blood vessels
| - cerebrospinal fluid
26
subdural space
- space containing serous fluid
| - space between dura and arachnoid
27
epidural space
- a space separates wall of the vertebral canal and the dura mater
- contains spinal nerve roots, blood vessels, areolar connective tissue and adipose tissue
28
reflex of opposite limb when one limb flexor muscle contracts;
crossed extensor reflex
29
bundle of ______ (axons) is surrounded by ________.
fascicle
| perineurium
30
Tibial nerve and common fibular nerve form;
sciatic nerve
| = the largest peripheral nerve
31
smallest, simplest portion of nervous system receives a stimulus and produces response;
reflex arc
32
withdrawal reflex
- promotes the removal of a body part from a painful stimulus
- contains pain receptor
- excitatory interneuron synapses with an alpha motor neuron
33
brain and spinal cord is surrounded by connective tissue called;
meninges
34
spinal reflex can;
- be influenced by descending tracts
| - interact with ascending tracts
35
basic unit of nervous system is;
neuron
36
ventral rami (ramus);
- form intercostal nerves
| - innervate the intercostal muscles and the skin over the thorax
37
deepest meningeal layer tightly attached to the spinal cord and brain is;
pia mater
38
phrenic nerve;
cervical plexus
| - innervates diaphragm
39
axillary nerve;
shoulder
- teres minor
- deltoid
40
radial nerve;
posterior arm, forearm, hand
41
ulnar nerve
medial side of hand (half)
42
median nerve innervate;
- palmaris longus
- flexor carpi radialis
- flexor policis longus
43
what is Golgi tendon organs?
nerve endings in tendons
44
dorsal roots contain;
- sensory axons
| - unipolar neurons
45
ventral roots contain;
motor axons & multipolar neurons (that innervate skeletal muscle)
46
spinal nerve has;
both sensory and motor
| axons/axons of both unipolar and multipolar neurons
47
lateral horn contains;
cell bodies of multi-polar neurons of the autonomic system: smooth muscle, cardiac muscle, glands, involuntary ( parasympathetic & sympathetic)
48
spinal reflexes can;
- be influenced by descending tracts
| - interact with ascending tracts
49
monosynaptic reflex;
sensory neurons synapse directly with motor neurons
50
polysynaptic reflex;
- complex pathway
| - 1 or more interneurons between the sensory and motor neurons
51
reciprocal innervation;
relaxation of extensor muscle while opposing flexor muscle contract
52
ventral rami;
innervate intercostal muscles and skin over thorax
53
white matter consists;
myelinated axons
54
gray matter consists;
- cell bodies of neurons
- dendrites
- Myelinated axons
55
area of skin supplied with sensory innervation by spinal nerves;
= dermatome / dermatomal map
56
dorsal root contain;
sensory axons
57
ventral root contain;
motor axons
58
PNS General disorders;
Anesthesia - loss of sensation
- hyperesthesia : sensitivity to pain, light, pressure
- paresthesia : tingling, burning
- Neuralgia : nerve inflammation, stabbing pain
- sciatica : radiating paying back of thigh/leg
59
PNS Infections
- herpes : herpesvirus / inflammation of skin
- shingles / herpes zoster : one spot/certain receptor
- poliomyelitis : infantile paralysis
60
PNS genetic and autoimmune disorders
- myasthenia gravis = result in fatigue and muscular weakness due to inadequate ACh receptors
61
What is reflex?
Basic unit of nervous system and simplest portion of receiving stimulus and producing response.
