Exam 4 Flashcards
(111 cards)
1
Q
neural tube development
A
thickening of ectoderm called neural plate at 3 wks
invagination of neural plate forms neural groove and
neural folds
the fusing of neural folds creates the neural tube at 4
wks
migrating neural folds cell forms neural crest
differentiates into anterior and posterior end
2
Q
primary brain vesicles
A
prosencephalon (forebrain)
mesencephalon (midbrain)
rhombencephalon (hindbrain)
3
Q
secondary brain vesicles
A
telencephalon (cerebrum) diencephalon brainstem metencephalon (pons and cerebellum) myelencephalon (medulla)
4
Q
characteristics of brain ventricles
A
hollow chambers filled with CSF and lined with
ependymal cells
arise from expansions of embryonic neural tube
continuous with another and central canal and spinal
cord
5
Q
lateral ventricle (horns)
A
paired ventricles deep within the cerebrum
C-shaped
6
Q
third ventricle (birds head)
A
located in the diencephalon communicate with the lateral ventricles via the intraventricular foramen
7
Q
fourth ventricle (diamond)
A
hindbrain dorsal to the pons and superior to medulla
communicated with the third ventricle via the cerebral
aqueduct
continuous with central canal and spinal cord
8
Q
characteristics of cerebrum
A
the most superior part of the brain
83% of total brain mass
grey matter on the outside
white matter on inside
9
Q
lobes of cerebrum
A
frontal, parietal, occipital, temporal, insula
10
Q
longiitudinal fissure
A
separates the left and right cerebral hemispheres
11
Q
transverse fissure
A
cerebrum from cerebellum
12
Q
central sulcus
A
frontal and parietal lobes
13
Q
lateral sulcus
A
temporal from frontal and parietal
14
Q
parieto-occipital
A
parietal and occipital
only seen in midsaggital section
15
Q
characteristics of the cerebral cortex
A
2-4 mm thick, convoluted
40% of total brain mass
grey matter
the conscious mind, perceive, communicate, remember, understand, voluntary movement
16
Q
cerebral lateralization
A
hemispheres are not symmetrical have specializations
17
Q
primary (somatic) motor cortex
A
precentral gyrus of frontal lobe
conscious control of voluntary movement
18
Q
premotor area
A
anterior to precentral gyrus
control repetitious or patterned learned motor skills
typing, playing instruments
19
Q
Broca’s area
A
inferior to left frontal lobe
motor speech area controlling muscles used in speech
20
Q
primary somatosensory cortex
A
postcentral gyrus of the parietal lobe
information from somatic sensory receptors and proprioceptions
21
Q
somatosensory association cortex
A
posterior to the postcentral gyrus
integrate sensory inputs to comprehend objects being felt
22
Q
primary visual area
A
posterior occipital lobe
vision (info from the retina)
23
Q
olfactory cortex
A
medial aspect of temporal lobe
smell (olfactions)
24
Q
primary auditory cortex
A
the superior aspect of the temporal lobe
sound
25
prefrontal cortex
anterior to the frontal lobe
| higher intellectual activity, personality, judgment, and planning
26
posterior association area
parts of temporal, parietal, and occipital
| awareness of yourself in surroundings
27
Wernicke's area
left posterior temporal lobe
| understanding written and spoken language
28
sensroy and motor homunculus
entire body spatially represented primary sensory and primary motor areas
the left side of the brain controls the right side of the body
29
cerebral white matter
deep to the grey matter
| composed of myelinate and unmyelinated axons bundles into tracts
30
commissural fibers
connect corresponding cortical areas of the hemispheres
| largest is the corpus callosum
31
association fibers
connect different parts of the same hemispheres
32
projection fibers
connect higher and lower brain structures
runs through the internal capsule between the thalamus and basal nuclei
create corona radiata
33
basal ganglia
masses of grey matter deep within cerebral white matter in each hemisphere
regulate attention and cognition
motor control
34
lentiform nucleus
puntamen and globus pallidus
| laterally to internal capsule
35
caudate nucleus
a comma-shaped nucleus that arches superiorly over the diencephalon
36
corpus striatum
lentiform and caudate nucleus
37
characteristics of diencephalon
the central core (grey matter) of the forebrain
surrounded by cerebral hemispheres
3-paired structures surrounding 3rd ventricle
38
thalamus
contains over 20 nuclei
major sensory integration and relay station
all sensory fibers except smell synapse here
39
hypothalamus
the main visceral control center of the body, maintain homeostasis
heart rate, BP, digestive, pupil size, body thermostat, pleasure, fear, rage, sex drive
regulate food intake, water balance, thirst, sleep-wake cycles
40
epithalamus
contains pineal gland that releases melatonin
| sleep-inducing signal, regulate sleep-wake cycles
41
cerebral peduncles
composed of corticospinal motor tracts
42
periaqueductual grey matter
pain suppression and links the amygdala to fight or flight pathways
43
corpora quadrigemina
superior colliculi: visual reflex center, coordinate head, and eye movement
inferior colliculi: auditory reflex center, turn head towards the sound
44
substantia nigra
makes dopamine
| degeneration causes Parkinson's disease
45
red nucleus
deep to substantia nigra
| affect limb flexion
46
pons
composed of conduction tracts
connect the higher brain to the spinal cord via deep projection fibers
superficial fibers connect pons to the cerebellum
respiratory centers, control normal breathing rhythms
47
medulla oblongata
pyramids
cardiovascular center-adjusts force and rate of heart, regulate BP
respiratory center: respiratory rhythm, control rate, and depth of breathing
visceral centers: regulate vomit, hiccupping, swallowing, couching, sneezing
48
cerebellum
11% of brain mass
coordinate complex movements, maintain posture balance
activity is subconscious
cognition, language, problem-solving
49
functional brain systems
networks of neurons that work together but span large distances and are difficult to localize
50
limbic system
emotional or affective brain
| encircles the upper part of the brainstem
51
cingulate gyrus of the limbic system
express motion via gestures, resolving mental conflicts when frustrated
52
hippocampus
storage and retrieved of long term memory
53
amygdala
recognize the angry or fearful facial expression, assess danger, elicits fear response
54
the hypothalamus in the limbic system
output runs through here
| clearinghouse for visceral and emotional responses
55
anterior thalamic nuclei
sensory relay station
56
mammillary body
olfactory relay station
57
reticular activating system
all ascending sensory tracts synapse here to keep us conscious and awake
filters out unnecessary stimuli
LSD interferes and causes sensory overload
inhibited by sleep center of the hypothalamus, depressed by alcohol, sleeping pills, and tranquilizers
58
dura mater
```
outermost layer
double layer of fibrous connective tissue except where it forms dural venous sinus
limits brain movement
falx cerebri: longitudinal fissures
falx cerebelli: vermis of cerebellum
tentorium cerebelli: transverse fissure
```
59
arachnoid mater
middle web-like layer
| contains largest blood vessels, serving brain
60
pia mater
innermost intimate with nervous tissue
61
cerebral spinal fluid
contains less protein than plasma
more Na, Cl, H than blood
less Ca and K than blood
62
production of CSF
made by specialized capillaries in ventricles called choroid plexus
capillaries are fenestrated allowing the tissue to pass
covered with pia mater and ependymal cells connected via tight junctions
tissue fluid leaks out into intercellular spaces
63
trace flow of CSF
lateral ventricles - interventricular foramen - third ventricle - cerebral aqueduct - fourth ventricle - central canal of the spinal cord or median and lateral apertures - subarachnoid space - arachnoid villi - superior sagittal sinus
64
blood-brain barriers
the protective mechanism that helps maintain a stable environment from brain
what can pass: glucose, amino acid, electrolyte, fats, oxygen, CO2, alcohol, nicotine, anesthesia
what cannot pass: bloodborne metabolic wastes, proteins, toxins, most drugs
65
trace blood from the aorta to cerebral arteries
aorta from heart, brachiocephalic artery, into common carotid artery ( right and left),
SEE IMAGE
66
why is the circle of Willis important
provides blood from between the posterior and anterior of the brain
67
structural organization of nerves
endoneurium-around axon
perineurium- around nerve fascicles
epineurium- around entire nerve
68
CN 1 olfactory
olfactory receptor cells to the primary olfactory cortex
| olfaction (sensory only, SVA)
69
CN 2 optic
the retina of the eye to the primary visual cortex
| vision (sensory only SSA)
70
CN 3 oculomotor
ventral midbrain to eye
motor to extrinsic eye muscles (GSE)
parasympathetic to iris of eyes (GVE)
71
CN 4 trochlear
dorsal midbrain to extrinsic eye muscle
| motor to extrinsic eye muscle (GSE)
72
CN 5 trigeminal
face to pons and back
primary sensory nerve from face and head (GSA)
motor to the muscle of mastication (GSE)
73
CN 6 abducens
pons to extrinsic eye muscle
| motor to extrinsic eye muscle (GSE)
74
CN 7 facial
pons to face
motor to the muscles of facial expression (GSE)
parasympathetic to lacrimal and salivary glands (GVE)
taste from anterior 2/3 tongue (SVA)
75
CN 8 vestibulocochlear
vestibular branch; equilibrium (SSA)
| cochlear branch: hearing (SSA)
76
CN 9 glossopharyngeal
medulla to throat
motor to tongue and pharynx (GSE)
parasympathetic to salivary glands (GVE)
taste and general sensation from the tongue (SVA and GSA)
77
CN 10 vagus
medulla to neck, thorax, abdomen
parasympathetic fibers to thoracic and abdominal organs (GVE)
taste from the posterior tongue (SVA)
sensory from thoracic, abdominal viscera (GVA)
78
CN 11 accessory
cranial and spinal root to cranial roots join vagus and spinal roots to muscles
motor to the trapezius, sternocleidomasotid and pharynx (GSE)
79
CN 12 hypoglossal
medulla to tongue
| motor to the tongue, speech, and chewing (GSE)
80
characteristics of the spinal cord
two-way conduction pathway to and from the brain
reflex and integration center
from the foramen magnum to L2
protected by the vertebral column and meninges
31 pairs of spinal nerves
81
cervical enlargement of spin
where nerves for the brachial plexus arise
82
lumbar enlargement of spinal cord
where nerves for the lumbosacral plexus arise
83
structure of the spinal cord
```
grey matter in a butterfly shape
central canal
posterior/dorsal horns-sensory neurons
anterior/ventral horns-somatic motor neurons
lateral horns-autonomic motor neurons
white matter contains nerve tracts
```
84
the white matter of the spinal cord
ascending tracts carry afferent impulses to the brain
descending tracts carry efferent impulses away
commissural fibers cross the spinal cord to opposite sides
columns
85
trace a reflex
see image
86
reflex
rapid, unpredictable autonomic motor reaction to a stimulus
same response
unlearned, involuntary
integrated into the spinal cord
87
somatic reflex
voluntary (skeletal muscle)
88
visceral reflex
involuntary (smooth, cardiac muscles, glands)
89
innate reflex
born with it
90
acquired reflex
learned
91
spinal reflex
integrated into the spinal cord
92
cranial reflex
integrated into brain
93
monosynaptic reflex
1 sensory neuron and 1 motor neuron
stretch reflex/stretch is the stimulus
maintain muscle tone
knee jerk
94
polysynaptic reflex
```
1 sensory, 1 motor, and 1 interneuron
pain is the stimulus
rapid withdrawal of the limb
protective in nature
flexor withdraw
```
95
mechanoreceptors
physical stimuli including stretch
96
thermoreceptors
temperature
97
photoreceptors
light
98
chemoreceptors
chemicals
99
nociceptors
pian
100
proprioceptors
joint sense
101
dorsal column-medial lemniscal pathways
fasciculus cuneatus and fasiculus gracillis
fine touch, pressure, proprioceptions
1st order neuron have sensory receptor in the skin, enter the spinal cord and ascend to the medulla to synapse with 2nd order neuron
2nd order neuron decussate in the medulla and ascend to thalamus to synapse with 3rd neuron and directed to the postcentral gyrus of the cerebral cortex
102
lateral spinothalamic tract
pain and temperature
103
anterior spinothalamic tract
coarse touch and pressure
1st order neuron sensory receptors in the skin, enter the spinal cord via dorsal root and synapse with 2nd order
2nd order decussate and ascend in anterior and lateral white columns to thalamus to synapse with 3rd order
3rd order directed to the postcentral gyrus
104
anterior and posterior spinocerebellar tracts
proprioception for unconscious skeletal muscle coordination
1sr order have sensory receptors in skeletal muscle and tendons, enter the spinal cord via dorsal root and synapse with 2nd order
2nd order ascend in anterior and lateral column and end in the cerebellar cortex
105
lateral corticospinal tract
motor to skeletal muscle
upper motor neuron originates in the precentral gyrus and descends to the medulla where 80% decussate in pyramids and descend in a lateral white column
synapse with a lower motor neuron in the anterior horn
106
anterior corticospinal tract
motor to skeletal muscle
upper motor neuron originates in the precentral gyrus and descends in the anterior white column to a spinal level which exits and decussates
upper motor neuron synapses with lower motor neuron in ventral horn
107
extrapyramidal pathways
tectospinal tract: coordinate head and eye movements along superior colliculi
vestibulospinal and reticulospinal: maintain balance by varying the tone postural muscle
rubrospinal: control flexor muscle
108
paralysis
loss of motor function
109
flaccid paralysis
damage to ventral or anterior root cells/lower motor neuron damaged
no stimulation no movement
denervation atrophy
110
spastic paralysis
damage to upper motor neuron, muscles can be stimulated by spinal reflexes, AP to muscles, less atrophy
111
paresthesis
sensory loss
