Central Nervous System Flashcards
(69 cards)
1
Q
Functions of the spinal cord
A
- Conduction
- Neural integration
- Locomotion
- Reflexes
2
Q
Anatomy of spinal cord
A
- travels down to L1
- 31 pairs of spinal nerves
- know location of central canal, gray commisure, dorsal horn, ventral horn, lateral horn, dorsal root ganglion, ventral column, dorsal column, lateral column, gray matter, and white matter.
3
Q
Ascending tract
A
- goes up the spinal cord
- sensory information
- orginates from out in the body
- Travels to medulla (decussates here)
- Attaches to 2nd neuron receptor
- Travels up to the thalamus
- Thalamus interprets message and either leaves it there or passes it on to the brain
- destination is the somatosensory cortex
- decussates at medulla oblongata
- synapses at medulla/thalamus
4
Q
Descending tract
A
- motor/muscle contraction
- orginates from the motor cortex
- travels down either the anterior or lateral column
- destination is the muscles
- 2 neurons
- decussates at the medulla for the lateral column and the spinal cord for the anterior column
5
Q
Meninges
A
Fibrous membranes that separate the soft tissue of the Central Nervous System
6
Q
The 3 meninges and the spaces between
A
Epidural space Dura mater Subarachnoid space Arachnoid mater Cerebral spinal fluid Pia mater
7
Q
Nerve
A
Bundle of axons in peripheral nervous system
Surrounded by epineurium
Mixed-both sensory and motor info
Contains blood vessels and Schwann cells
8
Q
Ventral root
A
The branch of spinal nerve that emerges from the ventral side of the spinal cord that carries motor (efferent) nerve fibers
9
Q
Dorsal root
A
Emerges from the dorsal side of the spinal cord that carries after end (sensory) nerve fibers.
Contains dorsal root ganglion
10
Q
Number of pairs of spinal nerves on cervical section
A
8
C1-C8
11
Q
Number of pairs of spinal nerves in thoracic section
A
12
T1-T12
12
Q
Number of pairs of spinal nerves in lumbar section
A
5
L1-L5
13
Q
Number of pairs of spinal nerves in sacral section
A
5
S1-S5
14
Q
Number of pairs of spinal nerves in coccygeal section
A
1
C0
15
Q
Define nerve plexus
A
The anterior Rami branch and anastomose merge repeatedly to form 5 nerve plexuses
- cervical plexus
- brachial plexus
- lumbar plexus
- sacral plexus
- coccygeal plexus
16
Q
Cervical plexus
A
Neck
C1-C5
Supplies neck and phrenic nerve to diaphragm
17
Q
Brachial plexus
A
Near shoulder
C5-T1
Supplies upper limb and some of shoulder and neck
Median nerve-carpal tunnel syndrome
18
Q
Lumbar plexus
A
Lower back
L1-L4
Supplies abdominal wall, anterior thigh, and genitalia
19
Q
Sacral plexus
A
Pelvis
L4, L5, and S1-S4
Supplies remainder of lower trunk and lower limb
20
Q
Coccygeal plexus
A
S4, S5, and C0
21
Q
Somatic reflexes
A
Reflexes of the skeletal muscle
Enact the reflex arc
22
Q
Reflex arc
A
- Somatic receptors
-in skin, muscles, or tendons - Afferent nerve fibers-spinal cord
-carry info from receptors to posterior horn of spinal cord or brain stem - Integrating center-move inter neurons
-a point of synaptic contact between neurons in gray matter of spinal cord or brain stem. Determines whether efferent neurons issue signals to muscles. - Efferent nerve fibers-body/skeletal muscle
-carry motor impulses to skeletal muscle - Effectors-skeletal muscle
-somatic effectors carry out response
(Receptor>nerve>integrating center>nerve>effector)
23
Q
Monosynaptic reflex
A
- afferent sensory fibers from spinal cord synapse directly to the efferent motor neuron that return to the muscle.
- only one synapse between afferent and efferent neurons
- include stretch reflex
- faster
24
Q
Polysynaptic reflex
A
- neurons include: afferent sensory neuron, efferent motor neuron, 2 or more inter neurons
- due to delay of signal, efferent organ receives prolonged output from the spinal cord
- slower
25
Decussation/crossing over
As fibers pass up or down the brain stem and spinal cord they cross over from left to right and vice versa. Input received from the right side of the body crosses over and reaches the left side of the brain.
26
Spinothalamic tract
Carries information for pain, temperature, pressure, tickle, itch, and light touch.
27
Gracile fasciculus and cuneate fasciculus
- gracile fasciculus-upper trunk
- cuneate fasciculus- loser trunk
- pain, touch, balance, vibration
- first order neuron travels up to the medulla
- second order neuron decussates, travels to the thalamus
- their order neuron travels to the cortex
28
Corticospinal tract
- carries motor information down the lateral and anterior columns of the spinal cord
- lateral corticospinal tract: fibers decussate at the medulla
- anterior corticospinal tract: fibers remain uncrossed until lower in the spinal cord
29
Longitudinal fissure
Deep median groove that separates left and right hemisphere of brain
30
Sulci (sulcus)
Shallow grooves
| Central and lateral sulcus
31
Gyri (gurus)
Thick fold of the brain
32
Forebrain, midbrain, hindbrain
Vesicles of the brain
33
Diencephalon
Contains thalamus, hypothalamus, and pineal gland (epithalamus)
34
Meninges of the brain
Dura mater
-periosteal layer (part of the periosteal of bone of the skull)
Arachnoid mater
Pia mater
35
White matter in the Brain
Bundles of axons
Forms inner layer deep to cortical gray matter
Tracts-connect brain regions
36
Gray matter in the brain
Seat of neuron cell bodies, dendrites, and synapses.
Forms surface layer (cortex) over cerebrum and cerebellum
Forms nuclei deep within the brain
37
Ventricle
Fluid filled chamber of the brain
4 internal chambers of the brain
-2 lateral- one in each cerebral hemisphere
-3rd ventricle- single narrow medical space beneath corpus callosum
-4th ventricle- small triangular chamber between pons and cerebellum
38
Choroid plexus
Spongy mass of blood capillaries on the floor of each ventricle
Ependymal cells are neuralgia that lines the ventricles and covers choroid plexus
39
Cerebral spinal fluid circulation
1. CSF formed
2. Lateral ventricle
3. Intraventricular foramen
4. Third ventricle
5. Cerebral aqueduct
6. Fourth ventricle
7. Lateral median apetures
8. Subarachnoid space
9. Arachnoid granulation
10. Dural sinuses
11. Blood
12. Filtered through choroid plexus
Repeat.
40
Production of cerebral spinal fluid
Production begins with the filtration of blood plasma through the capillaries of the brain.
-ependymal cells modify the filtrate, so CSF has more sodium and chloride than plasma, but less potassium, calcium, glucose, and very little protein.
100-160 mL normally present at 1 time
41
Functions of CSF
Helps brain to be buoyant, provides protection, and helps with chemical stability
42
Insula
Mass of cortex deep below lateral sulcus
Plays a role in sensations like taste, pain, visceral sensation, consciousness, emotional responses, empathy, and cardiovascular homeostasis
43
Reticular formation
Network of nerve pathways up and down the brain stem
-gray matter goes all around the brain
Somatic motor control, cardiovascular control, pain, sleep, consciousness, and habituation.
44
Basal nuclei
Masses of gray matter deep in the cerebrum
Intentional movement, repetitive movement, and practiced behaviors
Secretes dopamine to stimulate/inhibit motor pathways
45
limbic System
Cingulate gyrus, hippocampus, amygdala, frontalis/temporal lobe, and thalamus.
Emotion, learning, and memory
46
Cranial nerve I
Olfactory
Smell
Sensory
47
Cranial nerve II
Optic
Vision
Sensory
48
Cranial nerve III
Oculomotor
Eyeball
Motor
49
Cranial nerve IV
Trochlear
Eyeball movement only
Motor
50
Cranial nerve V
Trigeminal
Mixed
Sensory-eye, face, scalp, mouth
Motor-chewing
51
Cranial nerve VI
Abducens
Eyeball movement only
Motor
52
Cranial nerve VII
Facial
Mixed
Sensory-taste
Motor-facial expressions, swallowing, salivary glands, and tears
53
Cranial nerve VIII
Vestibulacochlear
Mixed
Sensory-cochlear-hearing
Motor-vestibula-balance
54
Cranial nerve IX
Glossopharyngeal
Mixed
Sensory-taste
Motor-swallowing and salivary glands
55
Cranial nerve X
Vagus
Mixed-vm-EVERYTHING
Sensory-esophagus and ear
Motor- speech and swallowing
56
Cranial nerve XI
Accessory
Motor
Speech, swallowing, neck and shoulder muscle
57
Cranial nerve XII
Hypoglossal
Motor
Tongue, speech, chewing, and swallowing
58
Sensation
- primary sensory cortex
- sensory input received
- association areas
- sensory input received
- special senses
- limited to head
- vision, hearing, equillibrium, taste, and smell
- general senses
- around the body
- touch, pressure, temperature
59
Chemoreceptors
Chemicals
60
Thermoreceptors
Temperature
61
Mechanoreceptors
```
Mechanical stress
(Sense of touch and BP)
```
62
Photoreceptors
Light
| Sight
63
Nocireceptors
Pain
64
Proprioreceptors
Space
| Learning, standing
65
Visceral reflexes
-unconscious, automatic, stereotyped responses to stimulation
-reflex arc
1. Receptors-nerve endings that detect stretch, tissue damage, blood chemicals, body temp, and other internal stimuli
2. Afferent neurons- leading to CNS
3. Inter neurons- in CNS- integrator
4. Efferent neurons- carry motor signals away from CNS
Slower
Regulate heart rate, bl, air flow, temp, digestion, urination, and defecation.
66
Sympathetic
Stress/excitatory inducing (fight or flight)
Short preganglion
Long postganglion
3 routes:
-spinal nerve>ganglia>spinal nerve>effector
-sympathetic nerve>ganglia>sympathetic nerve>effector
-splanchnic>separate ganglion>effector
67
Parasympathetic
```
Relaxing effect on the body
Long preganglionic fiber
Short postganglionic fiber
Normal/digesting branch
Close to organ it’s traveling to
Secretes ACh
```
68
Acetylcholine (ACh)
```
Cholinergic fiber
Muscarthic receptor
-mostly excitatory can be inhibitory
Nicotinic receptor
-always excitatory
-all preganglion neurons secrete ACh
-parasympathetic postganglions secrete ACh
```
69
Norepinephrine (NE)
```
Adrenergic fiber
Alpha-adrenergic receptor
-Ca+/CAMP as 2nd messenger
-most are excitatory
Beta-adrenergic receptor
-CAMP as 2nd messenger
-most are inhibitory
```
