Spinal Cord and Nerves Flashcards
(111 cards)
1
Q
The spinal cord contains what?
A
Neural circuits
2
Q
What does the spinal cord do?
A
Controls some of the quickest reactions to environmental changes.
3
Q
The site for integration of neuronal stimulation is where?
A
Spinal Cord
4
Q
What does the spinal cord relay?
A
Sensory nerve impulses
5
Q
What is the outer layer of meninges?
A
Dura Mater
6
Q
Where is outer layer of the meninges located?
A
Epidural space
7
Q
What is the middle layer of the meninges?
A
Arachnoid Mater
8
Q
Where is the middle layer of the meninges located?
A
Subarachnoid space with cerebrospinal fluid.
9
Q
What is the inner layer of meninges?
A
Pia mater
Delicate
10
Q
Where is the inner layer of the meninges located?
A
Coccygeal and Denticulate ligaments.
11
Q
What are meninges?
A
Connective tissue coverings that encircle the spinal cord and brain.
12
Q
What is outer layer of meninges composed of?
A
Dense irregular connective tissue.
13
Q
What is the middle layer of meninges composed of?
A
It’s an avascular covering composed of delicate collagen fibers and some elastic fibers.
14
Q
What is the layer between the dura mater and the arachnoid mater?
A
Subdural space
15
Q
What are denticulate ligaments?
A
Thickenings of the Pia mater suspend the spinal cord in the middle of the dural sheath.
16
Q
What shape is the spinal cord?
A
Oval
17
Q
Where does the spinal cord extend from?
A
The medulla oblongata to the superior border of the second lumbar vertebra.
18
Q
What is the length of the adult spinal cord?
A
42-45 cm
19
Q
What are the two conspicuous enlargements in the spinal cord?
A
Cervical enlargement
Lumbar enlargement
20
Q
What is the tapering end of the spinal cord inferior to the lumbar enlargement called?
A
Conus Medullaris
21
Q
Where does the tapering end of the spinal cord end?
A
Ends at the level of the intervertebral disc between the first and second lumbar vertebrae.
22
Q
What is the extension of the Pia mater?
A
Filum Terminale
23
Q
What does the film terminals fuse with?
A
Arachnoid mater and dura mater, anchors the spinal cord to the coccyx.
24
Q
What are spinal nerves?
A
Paths of communication between the spinal cord and specific regions of the body.
25
What does each pair of spinal nerves have?
Spinal segment
26
How many pairs of cervical nerves are there?
8
27
How many pairs of sacral nerves are there?
5
28
How many pairs of coccygeal nerves are there?
1
29
What connects the spinal nerve to the segment of the cord?
Rootlets
30
The posterior (dorsal) root conduct nerve impulses for what?
Sensory receptors in the skin, muscles, and internal organs into the central nervous system.
31
The anterior (ventral) root contains neurons for what?
Motor neurons, which conduct nerve impulses from the CNS to effectors (muscles and glands)
32
What contains the cell bodies of sensory neurons?
Posterior (dorsal) root ganglion
33
What is formed by roots of the lumbar, sacral and coccygeal nerves around the film terminale?
Cauda Equina
34
What is the outer layer of the spinal cord?
White Matter
35
What is the inner layer of the spinal cord?
Gray Matter
36
What does white matter consist of?
Myelinated axons of neurons
37
What are the three regions of the white matter?
Anterior White columns
Posterior White columns
Lateral White columns
38
What are tracts?
Bundle of axons, which may extend long distances up or down the spinal cord.
39
What direction do sensory tracts go?
Conduct nerve impulses toward the brain
40
What direction do motor tracts go?
Carry nerve impulses from the brain to the target tissue.
41
What is gray matter shaped as?
An H or butterfly in the center of the spinal cord.
42
What does gray matter consist of?
Dendrites and cell bodies of neurons, unmyelinated axons, and neuroglia.
43
What forms the crossbar of the H?
Gray Commissure
44
What is the central canal filled with?
Cerebrospinal fluid
45
What is the central canal continuous with at the superior end?
The fourth ventricle in the medulla oblongata
46
What receives input from receptors via sensory neurons?
Sensory nuclei
47
What provides output to effector tissues via motor neurons?
Motor Nuclei
48
What connects the white matter of the right and left sides of the spinal cord?
Anterior White Commissure
49
What is gray matter subdivided into?
Horns
50
What horn contains cell bodies and axons of interneurons and neurons of incoming sensory neurons?
Posterior Gray Horn
51
What contains the somatic motor nuclei and provides impulses for contraction of skeletal muscle?
Anterior Gray Horn
52
What lateral gray horns contain what?
The Sympathetic motor nuclei. Only in the thoracic and upper lumbar segments.
53
The spinal nerve is a ______ _______.
Mixed Nerve
54
Endoneurium is wrapped around.....
individual axons within a nerve, whether myelinated or unmyelinated.
55
Perineurium is wrapped around......
wrapped groups of axons with their endometrium in bundles.
56
What are the bundles of neurons called?
Fascicles
57
What is the outermost covering over the entire nerve called?
Epineurium
58
What ramus supplies muscles and skin of the back?
Posterior ramus
59
What does anterior ramus supply?
Supplies the muscles and structures of the upper and lower limbs and the skin of the lateral and anterior surfaces of the trunk.
60
What supplies the structures within the cavity?
Meningeal branch
61
The Rami Communicants is a component of what?
The autonomic nervous system
62
The white ramus, contains _________, sympathetic preganglionic axons.
Myelinated
63
The gray ramus, contains ___________, sympathetic postganglionic axons.
Unmyelinated
64
What are plexuses formed by?
The anterior rami of spinal nerves
| Except for thoracic nerves T2-T12.
65
Name the principle plexuses
Cervical plexus
Brachial plexus
Lumbar plexus
Sacral plexus
66
The cervical plexus is formed by nerves from where?
The anterior rami of the first four cervical nerves.
67
What does the cervical plexus supply?
The skin and muscles of the head, neck and superior part of the shoulders and chest.
68
Lesser Occipital nerve C2
Skin of the scalp posterior and superior to the ear
69
Great auricular nerve (C2 and C3)
Skin Anterior, inferior and over ear, and over parotid glands.
70
Transverse cervical (C2-C3)
Skin over anterior and lateral aspect of neck
71
Supraclavicular (C3-C4)
Skin over superior portion of chest and shoulder
72
What arises from the cervical plexus?
Phrenic nerves
73
What do the phrenic nerves supply?
Motor fibers to the diaphragm.
74
The brachial plexus is formed from nerves from where?
C5-C8 and T-1
75
What does the brachial plexus divide into?
```
Roots
Trunks
Divisions
Cords
Branches
```
76
Axillary nerve
Supplies the deltoid and trees minor muscles
77
Musculocutaneous nerve
Supplies the anterior muscles of the arm
78
Radial Nerve
Supplies the muscles on the posterior aspect of the arm and forearm.
79
Median Nerve
Supplies most of the muscles of the anterior forearm and some of the muscles of the hand.
80
Ulnar nerve
Supplies the anteromedial muscles of the forearm and most of the muscles of the hand.
81
Where does the Lumbar plexus originate from?
L1-L4
82
What does the lumbar plexus supply?
The anterolateral abdominal wall, external genitals, and part of the lower limb.
83
Femoral Nerve
Supplies flexor muscles of hip join and extensor muscles of knee joint, skin over anterior and medial aspect of thigh and medial side of leg and foot.
84
Obturator Nerve
Adductor muscles of hip joint; skin over medial spect of thigh.
85
The Sacral plexus is formed by anterior rami from what spinal nerves?
L4-L5, and S1-S4.
86
What does the sacral plexus supply?
Butt, perineum and lower limbs
87
What is the largest nerve in the body?
Sciatic nerve
88
Where does sciatic nerve split?
Level of the knee into tibial and common fibular nerves.
89
What is the coccygeal plexus formed by?
S4-S5, and coccygeal nerves
90
The compression or irritation of the sciatic nerve is referred to as?
Sciatica
91
What are dermatomes?
Areas of the skin that provides sensory input to the CNS via one pair of spinal nerves.
92
Sensory input travels along the _________ _______ ______, towards the brain.
White matter tracts
93
What area of the spinal cord receives and integrates incoming and outgoing information?
Gray Matter
94
Ascending tracts convey _________ sensation from spinal cord to the brain.
Sensory
95
What conducts cutaneous sensation from receptors to the brain and spinal cord?
1st dorsal root ganglia
96
What transmits impulses to the thalamus and cerebellum?
2nd in the dorsal horn of spinal cord or in medullary nuclei
97
What conducts impulses to sensory cortex of the cerebrum cortes or cerebellum?
3rd in Thalamus
98
What tract ascends and ends in the medulla?
Posterior column
99
What posterior column ascends from the lower limb?
Gracile fascicules
100
What posterior column ascends from the upper limb?
Cuneate fasciculus
101
What tract carries pain and temperature sensation to the thalamus?
Spinothalamic tract
102
What is a fast, involuntary, unplanned sequence of actions that occurs in response to a particular stimulus?
Reflex
103
A spinal reflex takes place where?
The spinal cord, gray matter.
104
Where does a cranial reflex occur?
The brain stem.
105
An example of the cranial reflex is....
Tracking movement of your eyes.
106
What is the reflex associated with the contraction of skeletal muscles?
Somatic reflexes
107
What reflex is associated with the response of smooth muscle, cardiac muscle, and glands?
Autonomic reflexes
108
What is a reflex?
A neural pathway followed by nerve impulses that produce a reflex.
109
What are the five functional components of a reflux?
```
Sensory Receptor
Sensory neuron
Integrating center
Motor Neuron
Effector
```
110
What is an effector?
The part of the body that responds to the motor nerve impulse, such as a muscle or gland.
111
What is the integrating center?
A single synapse between a sensory neuron and a motor neuron.
