Anatomy & Physiology Flashcards
(124 cards)
1
Q
What are the CNS/PNS origins?
A
Neuroectoderm, Neural crest & mesoderm
2
Q
What cells originate from Neuroectoderm?
A
- CNS neurons
- Ependymal cells
- Oligodendroglia
- Astrocytes
3
Q
What are Ependymal cells?
A
Inner lining of ventricles that make CSF
4
Q
What cells originate from Neural crest?
A
PNS neurons & Schwann cells
5
Q
What cells originate from Mesoderm?
A
Microglia
6
Q
What are Neurons?
A
Signal-transmitting cells of the nervous system
Permanent cells–do NOT divide in adulthood
7
Q
Which cells do Neurons signal-relay w/?
A
- Dendrites (receive input)
- Cell bodies
- Axons (send output)
8
Q
What does Nissl substance stain?
A
RER in cell bodies & dendrites
RER is NOT in axons
9
Q
What does an axon undergo when it is injured?
A
Wallerian degeneration
10
Q
What is Wallerian degeneration?
A
Degeneration distal to the injury & axonal retraction proximally
11
Q
What does Wallerian degeneration allow for?
A
Potential regeneration of axon if in PNS
12
Q
What do Astrocytes do?
A
- Physical support
- Repair K+ metabolism
- Removal of excess neurotransmitter
- Maintenance of BBB
13
Q
What do Astrocytes do in response to injury?
A
Reactive gliosis
14
Q
What is the marker for Astrocytes?
A
GFAP
15
Q
What are Microglia?
A
CNS phagocytes w/ Mesodermal origin
16
Q
Do microglia stain w/ Nissl stains?
A
No
17
Q
What is the histology of Microglia?
A
Small irregular nuceli & relatively little cytoplasm
18
Q
What do Microglia do?
A
Scavenger cells of the CNS
Respond to tissue damage by differentiating into large phagocytic cells
19
Q
What happens to HIV-infected microglia?
A
Microglia fuse to from multinucleated giant cells in the CNS
20
Q
What is Myelin?
A
Wraps & insulates axons→ Inc space constant & inc conduction velocity of signals transmitted down axons
21
Q
What does Myelin result in?
A
Saltatory conduction of AP b/w nodes of Ranvier where there are high conc of Na+ channels
22
Q
What are the Myelin cells of the CNS?
A
Oligodendrocytes
23
Q
What are the Myelin cells of the PNS?
A
Schwann cells
24
Q
What are oligodendroglia?
A
Each oligodendrocytes myelinates multiple CNS axons (up to 50 each)
25
What do Oligodendroglia look like on a Nissl stain?
Appear as small nuclei w/ dark chromatin & little cytoplasm
26
What is the predominate glial cell in white matter?
Oligodendroglia
27
What do Oligodendroglia look like on H&E stain?
Fried eggs
28
When can Oligodendroglia be destroyed?
Multiple Sclerosis
29
How man axons do Schwann cells myelinate?
1 PNS axon
30
What do Schwann cells promote?
axonal regeneration
31
When can Schwann cells be destroyed?
Guillain-Barre syndrome
32
What is Acoustic neuroma?
Type of Schwannoma
33
Where are Acoustic neuromas usually located?
Internal acoustic meatus (CN VIII)
34
What are free nerve endings?
* C--slow, unmyelinated fibers
* A delta--fast, myelinated fibers
35
Where are free nerve endings located?
All skin, epidermis, some viscera
36
What do free nerve endings sense?
Pain & temp
37
What are Meissner's corpuscles?
Large, myelinated fibers
Adapt quickly
38
Where are Meissner's corpuscles located?
Glabrous (hairless) skin
39
What do Meissner's corpuscles sense?
Dynamic, fine/light touch
Position sense
40
What are Pacinian corpuscles?
Large, myelinated fibers
41
Where are Pacinian corpuscles located?
Deep skin layers, ligaments & joints
42
What do Pacinian corpuscles sense?
Vibration & pressure
43
What are Merkel's discs?
Large, myelinated fibers
Adapt slowly
44
Where are merkel's discs located?
Hair follicles
45
What do Merkel's discs sense?
pressure, deep static touch & position sense
46
What is Endoneurium?
Invests single nerve fiber layers
| (Inner)
47
What is the inflam infiltrate in Guillian-Biarre?
Endoneurium
48
What is Perineurium?
Surrounds a fascicle of nerve fibers
| (around)
49
What must be rejoined in microsurgery for limb reattachment?
Perineurium
50
What is Epineurium?
Dense connective tissue that surrounds entire nerve (fasicles & BV)
(outer)
51
What are the different kinds of neurotransmitters?
* NE
* Dopamine
* 5-HT
* ACh
* GABA
52
How does NE change in disease?
* Inc in anxiety
* Dec in depression
53
Where is NE synthesized?
Locus creuleus (pons)
54
What is Locus ceruleus involved in?
Sress & panic
55
How does Dopamine change in dz?
* Inc in Schizophrenia
* Dec in Parkinson's
* Dec in depression
56
Where is Dopamine synthesized?
Ventral tegmentum & SNc (midbrain)
57
How does 5-HT change in dz?
Dec in anxiety & depression
58
Where is 5-HT synthesized?
Raphe nucleus (pons)
59
How does ACh change in dz?
* Dec in Alzhemier's
* Dec in Huntington's
* Inc inc REM sleep
60
Where is ACh synthesized?
Basal nucleus of Meynert
61
How does GABA change in dz?
Dec in anxiety & Huntington's
62
Where is GABA synthesized?
Nucleus accumbens
63
What are Nucleus accumbens & septal nucleus involved in?
Reward center, plesure, addiction & fear
64
What is the Blood Brain Barrier?
Prevents circulating blood substances from reaching the CSF/CNS
65
What are the 3 structures that form the BBB?
* Tight junctions b/w nonfenestrated capillary endothelial cells
* Basement membrane
* Astrocyte foot processes
66
How does glucose & aa cross the BBB?
Slowly by carrier mediated transport mech
67
How do nonpolar/lipid-soluble substances cross the BBB?
Rapidly via diffusion
68
What causes vasogenic edema?
Infarction &/or neoplasm destroys endothelial cell tight junctions
69
What inputs/outputs permeate the BBB?
Hypothalamic
70
What is the purpose of the BBB?
Prevent bacterial infection from spreading to CNS & restrict drug delivery to the brain
71
Hypothalamus wears **TAN HATS**
* **T**hirst & water balance
* **A**denohypophysis control (reg ant pit)
* **N**eurohypophysis releases hormones
* **H**unger
* **A**utonomic regulation
* **S**exual urges
72
Inputs to the hypothalamus
* OVLT (sense changes in osmolarity)
* Area postrema (responds to emetics)
* Areas no protected by BBB
73
What lines areas not protected by the BBB?
Fenestrated capillaries that allow molecules to pass
74
What makes ADH?
Supraoptic nucleus of the Hypothalamus
75
What makes oxytocin?
Paraventricular nucleus of the Hypothalamus
76
Where are ADH & oxytocin stored & released?
Posterior pituitary
77
What does the Lateral area control?
Hunger
78
What happens if the Lateral area is destroyed?
Anorexia or failure to thrive (infants)
79
The Lateral area is ______ by Leptin
Inhibited
80
What does the Ventromedial area control?
Satiety
81
What happens if the Ventromedial area is destroyed?
Hyperphagia
ex) craniopharyngioma
82
The Ventromedial area is _______ by Leptin
Stimulated
83
What does the Anterior Hypothalamus control?
Cooling
PNS
84
What does the Posterior hypothalamus control?
Heating
SNS
85
What happens if the Posterio hypothalamus is destroyed?
Become poikioltherm
| (cold blooded)
86
What does the suprachiasmatic nucleus control?
Circadian rhythm
87
The Neurohypophysis (post pit) receives hypothalamic axonal projections from ___ & \_\_\_.
Supraoptic (ADH) & paraventricular (oxytocin) nuclei
88
What is the adenohypophysis?
Anterior Pituitary
89
What is the Thalamus?
Major relay for all ascending sensory info except olfaction
90
What are the 5 major Thalamic nuclei?
* Ventral Posterior Lateral
* Ventral Posterior Medial
* Lateral Geniculate
* Medial Geniculate
* Ventral Lateral
91
What is the input for the Ventral Posterior lateral (VPL) nucleus?
Spinothalamic & dorsal columns/medial lemniscus
92
What info does the VPL interpret?
* Pain
* Temp
* Pressure
* Touch
* Vibration
* Proprioception
93
Where is the destination for VPL nucleus info?
1° somatosensory cortex
94
What is the input for the Ventral Posterior Medial (VPM) nucleus?
Trigeminal & gustatory pathway
95
What infodo the VPM interpret?
Face sensation & taste
96
Where is the destination for VPM nucleus info?
1° somatosensory cortex
97
What is the input for the Lateral Geniculate nucleus (LGN)?
CN II
98
What info does the LGN interpert?
Vision
99
What is the destination for LGN info?
Calcarine sulcus
100
What is the input for the Medial Geniculate nucleus (MGN)?
Superior olive & inferior colliculus of tectum
101
What info does the MGN interpret?
Hearing
102
What is the destination for MGN info?
Auditory cortex of temporal lobe
103
What is the input for the Ventral Lateral nucleus (VLN)?
Basal ganglia
104
What info does the VLN interpret?
Motor
105
What is the destination for VLN info?
Motor cortex
106
What is the Limbic system?
Collection of neural structures involved in emotion, LT memory, olfaction, behavior modulation & ANS function
107
What structures are the included in the Limbic system?
* Hippocampus
* Amygdala
* Fornix
* Mammillary bodies
* Cingulate gyrus
108
What is the Limbic system responsible for?
* Feeding
* Fleeing
* Fighting
* Feeling
* Sex
109
What does the Cerebellum do?
Modulates movement
Aids in coordination & balance
110
What is the input to the Cerebellum?
* Contralateral cortex via middle cerebellar peduncle
* Ipsilateral proprioceptive info via interior cerebella peduncle from the SC
111
What are the input nerves to the Cerebellum?
Climbing & mossy fibers
112
What is the output of the Cerebellum?
* Sends info to contralateral cortex to modulate movement
* Deep nuclei (lateral→ medial): Denate, Emboliform, Globose, Fastigial
113
What are the output nerves of the Cerebellum?
Purkinge fibers send info to deep nuclei of cerebellum which in turns sends info to the contralateral crotex via the superior cerebellar peduncle
114
What does the Lateral Cerebellum control?
Voluntary movement of extremeties
115
What happens when the lateral cerebellum is injured?
Propensitiy to fall forward on ipsilateral side
116
What does the Medial Cerebellum control?
Balance & truncal coordination
117
What does the Basal ganglia do?
Important in voluntary movements & making postural adjustments
118
What is the input to the Basal ganglia?
Cortex
119
What is the output of the basal ganglia?
Provides negative feedback to cortex to modulate movement
120
What is the Striatum of the Basal ganglia composed of?
Putamen (motor) & Cudate (cognitive)
121
What is the Lentiform of the Basal ganglia composed of?
Putamen & globus pallidus
122
What does the Excitatory pathway of the Basal ganglia do?
Cortical inputs stim the striatum→ stim the release of GABA→ disinhibits the thalamus via the GPi/SNR
(Inc motion)
123
What does the Inhibitory pathway of the Basal ganglia do?
Cortical inputs stim the striatum→ disinhibits STN via GPe→ STN stim GPi/SNr to inhibit the thalamus
(Dec motion)
124
What is the role of Dopamine in the basal ganglia?
Dopamine binds to D1→ stim the excitatory pathway & D2→ inhibiting the inhibitory pathway→ Inc motion
