Lab 1- Nervous Tissue Flashcards
(92 cards)
1
Q
Cell body
A
Constitues nucleus and cytoplasm.
2
Q
Nucleus
A
DNA-containning structure of cell body.
3
Q
Axon hillock
A
Conic area of origin of axon.
4
Q
Dendrite
A
Branching extensions of cell body providing structural pathway for afferent info.
5
Q
Axon
A
Structural pathway for efferent info.
6
Q
Neurolemmocyte (Schwann cell) and Myelin Sheath
A
Cell that surround and myelinated axons in PNS.
-Myelin: insulates and rapid transmission of impulses.
7
Q
Nodes of Ranvier (neurofibril nodes)
A
Gap in myelin sheath allows formation of new AP, increases rate of impulse transmission.
8
Q
Telodendria
A
Distal branching of neural axon.
9
Q
Axon terminals = synaptic end bulbs
A
Axon terminates, communicates with subsequent cells.
neurotransmitters
10
Q
What is another word for sensory neuron?
A
Afferent
11
Q
What is another word for motor neuron?
A
Efferent
12
Q
What type of neuron is between sensory and motor neurons?
A
Interneurons (association neurons)
13
Q
Epineurium
A
Covering of entire nerve.
14
Q
Perineurium
A
surrounds group of nerve fibers forming a fascicle.
15
Q
Endoneurium
A
Wrapping of each nerve fiber.
16
Q
Fascicle
A
Small bundle of nerve fibers.
17
Q
Axon
A
long & single nerve-cell process.
18
Q
Myelin sheath
A
Fatty white substance surrounding axon.
19
Q
Tract
A
Collections of axons in CNS.
20
Q
Nerve
A
Collections of axons in PNS.
21
Q
Ganglia
A
Collections of neuron cell bodies in PNS.
22
Q
Nucleus/nuclei
A
Collections of neuron cell bodies in CNS.
23
Q
Cerebrospinal fluid (CSF) is found in the subarachnoid space, which is between the ________ and ________.
A
Arachnoid mater & Pia mater.
24
Q
The epidural space is between ________ and ______.
A
Vertebra & Dura mater.
25
Ventral root
(anterior root)
| Efferent = motor
26
Dorsal root
(posterior root)
| Afferent = sensory
27
Dorsal root ganglion
(posterior root ganglion)
| swelling of lateral SC containing sensory neuron cell bodies.
28
Spinal nerve
Merging of ventral and dorsal roots. (mixed nerve)
29
Does the dorsal root contain sensory or motor neurons?
Sensory
30
Does the ventral root contain sensory or motor neurons?
Motor
31
What is in the dorsal root ganglion?
collection of cell bodies in PNS.
32
What is gray matter composed of?
cell bodies & unmyelinated axons.
33
In which two spinal cord regions are the lateral gray horns present?
Thoracic & Lumbar.
34
What do the ascending tracts of the white columns convey?
Sensory info.
35
What do the descending tracts of white columns convey?
Motor info.
36
Name 2 diseases that cause destruction of the anterior horn motor neurons.
- Polio
| - ALS
37
Polio
initial flu like symptoms
38
ALS
unable to initiate and control muscle movement.
39
How many pairs of spinal nerves are there?
31
40
how many cervical?
8
41
how many thoracic?
12
42
how many lumbar?
5
43
how many sacral?
5
44
how many coccygeal?
1
45
Are spinal nerves sensory, motor or both?
Both
46
Describe how cervical spinal nerves are named/numbered.
numbered/named by the vertebrae below
| -except for C8 (between C7 & T1)
47
Describe how thoracic, lumbar, sacral, and coccyx spinal nerves are named/numbered.
Named after vertebra above.
48
The spinal nerves then branch and become ______.
Dorsal ramus and ventral ramus.
49
Posterior (dorsal) innervate ________.
The back
50
Anterior (ventral) rami will branch and anastomose to form________.
Nerves that go to appendages.
51
brachial Plexus C5-T1
1. Axillary nerve (C5-C6)
2. Radial nerve (C5-T1)
3. Musculocutaneous nerve (C5-T1)
4. Median nerve (C6-T1)
5. Ulnar nerve (C8-T1)
52
Which 2 muscles does the axillary nerve innervate?
Deltoid & Teres minor
53
hat is the sensory distribution of the axillary nerve?
Skin of shoulder
54
The musculocutaneous nerve innervates the _______ muscles of the arm.
Flexor
55
What is the sensory distribution of the musculocutaneous nerve?
Lateral surface of forearm.
56
What is the sensory distribution of the radial nerve?
Posterolateral hand including first digit.
57
The median nerve innerevates the ______ muscles of the forearm.
flexor
58
What is the sensory distribution of the median nerve?
Anterolateral surface of hand & posterior 2nd, 3rd, 1/2 of 4 digits.
59
The median nerve goes though the ______ tunnel of the wrist.
Carpal
60
What is the sensory distribution of the ulnar nerve?
Anterolateral and postero medial surface of hand, 1/2 of 4th & 5th digits.
61
Lumbar Plexus (T12-L4)
1. Femoral nerve (L2-L4)
| 2. Obturator nerve (L2-L4)
62
What does the femoral nerve innervate?
```
sensory = anterior medial thigh
motor = Quadriceps
```
63
What the the obturator nerve innervate?
```
Sensory = medial surface of thigh.
Motor = adductors of hip
```
64
Sacral Plexus (L4-S4)
1. Sciatic nerve (L4-S3)
- tibial nerve: posterior muscles of leg
- common fibular nerve: lateral and anterior muscles of the leg. innervates the buttock, lower limb, pelvis, perineum.
65
Sympathetic chain
1. Sympathetic chain ganglion
2. Rami communicates
- White ramus (preganglionic)
- Gray ramus (postganglionic)
66
What is a reflex?
An action that is performed as a response to a stimulus and without conscious thought.
67
Receptor
site of stimulus
68
Sensory neuron q
Transmits the afferent impulse to the CNS.
69
Control (integration) center
in the CNS where the sensory info is received and transferred to the motor neurons.
70
Motor neuron
Conducts efferent impulses from the integration center to an effector.
71
Effector
Muscle fiber or gland that responds to the efferent impulse.
72
What is an innate reflex? example
Connections that form between neurons during development.
| EX: blinking, swallowing
73
What is an acquired reflex? example
Learned overtime
| EX: riding a bike
74
What is a visceral (autonomic) reflex?
Controls actions of smooth muscle, glands, and adipose tissue.
EX: digestion, blood pressure
75
What is a somatic reflex?
control skeletal muscle contractions (include superficial stretch reflexes)
76
What is a spinal reflex?
important interconnections and processing events occur in spinal cord.
77
What is a cranial reflex?
integration center located in brain
| EX: pupil dilation, salivating
78
Describe monosynaptic reflexes
(fast) simplest reflex arc, sensory neuron synapses directly on a neuron.
79
Describe reflexes
Complexed with 1 or more interneuron between sensory and motor neurons. Interneurons involved can control several muscle groups and produce either excitatory or inhibitory polysynaptic potentials.
80
Describe a stretch reflex
(posture) stretching of a muscle activates a muscle spindle. Impulse transmitted by afferent fibers to spinal cord. Motor neurons in spinal cord cause stretched muscle to contract. Integration center causes antagonist muscle to relax (reciprocal inhibition).
Monosynaptic reflex: decreased reflexes should lead to suspicion that reflex arc has been affected. possible sensory nerve fiber or spinal cord gray matter (motor fibers), LMN lesions.
81
What is a muscle spindle?
bundle of specialized skeletal muscle fibers that act as sensory receptors.
82
ankle jerk (monosynaptic)
test spinal nerves S1 and S2
83
```
Knee jerk (patellar reflex)
(monosynaptic)
```
test spinal nerves L2, L3, L4
84
Biceps jerk
Test spinal nerves C5 and C6
85
What conditions would diminish reflexes?
Hyporeflexia
86
What conditions would cause increased reflexes?
Hyperreflexia
87
What is a tendon reflex?
causes muscle to relax
| -monitors external tension produced during muscular contraction, prevents tearing or breaking if tendons.
88
Is the tendon reflex monosynaptic or polysynaptic?
Polysynaptic
89
What is a Golgi tendon organ?
stretch receptor in tenon
90
Describe a withdrawal reflex?
flexor reflex- pain receptors activated causing automatic withdrawal of threatened body part.
91
What is reciprocal inhibition?
Interneurons in spinal cord prevent stretch reflex in antagonistic muscles.
92
Describe the crossed extensor reflex (ipsilateral and contralateral)
Complex reflex- maintains upright position if pain is generated in lower extremity. Pull foot back, the other leg responds to hold you upright. (step on glass)
