Lesson 15-16 Part I Flashcards
1
Q
rostral
A
toward the forehead
2
Q
caudal
A
toward the spinal cord
3
Q
cerebrum
A
largest part of the brain, 83% of brain volume
4
Q
name all the parts of the cerebrum (5)
A
- cerebral hemispheres
- gyri
- sulci
- longitudinal cerebral fissure
- corpus callosum
5
Q
cerebral hemispheres
A
pairs of half globes of the cerebrum
6
Q
gyri
A
thick folds on the cerebrum surface
7
Q
sulci
A
shallow grooves between gyri
8
Q
longitudinal cerebral fissure
A
the deep groove that separates cerebral hemispheres
9
Q
corpus callosum
A
thick nerve bundle at the bottom of the longitudinal fissure that connects hemispheres
10
Q
cerebellum
A
second largest part of the brain; separated from cerebrum by transverse cerebral fissure; also has fissures, sulci, gyri
11
Q
the cerebellum is separated from the cerebrum buy the _____ _____ _____
A
transverse cerebral fissure
12
Q
brainstem
A
smallest portion of the brain
13
Q
what does the brainstem include?(3)
A
midbrain, pons, and medulla oblongata
14
Q
gray matter
A
contains nerve cell bodies, dendrites, and unmyelinated axons, synapses
15
Q
cortex
A
surface layer of gray matter in the cerebrum and cerebellum
16
Q
nuclei
A
deeper masses of gray matter, surrounded by white matter
17
Q
white matter
A
bundles of myelinated nerve fibers that connect one part of the brain to another and to the spinal cord
18
Q
what is white matter composed of?
A
tracts, bundles of myelinated nerve fibers
19
Q
the nervous system developed from the _____, the outermost tissue layer of the embryo
A
ectoderm
20
Q
by the fourth week, the neural tube that was formed from the ectoderm exhibits three primary vesicles at its anterior end:
A
- forebrain (prosencephalon)
- midbrain (mesencephalon)
- hindbrain (rhombencephalon)
21
Q
by the fifth week, the forebrain divides into two vesicles:
A
telencephalon and the diencephalon
22
Q
by the fifth week, the midbrain…
A
remains undivided and retained the name mesencephalon
23
Q
by the fifth week, the hindbrain divides into two vesicles:
A
metencephalon and myelencephalon
24
Q
meninges
A
the three membranes surrounding the brain and spinal cord that lie between the nervous tissue and bone
25
from outermost to innermost, the meninges are called...
- dura mater
- arachnoid mater
- pia mater
26
what do meninges do?
protect the brain and provide a structural framework for its arteries and veins
27
the dura mater is composed of two layers:
periosteal layer and meningeal layer
28
dura mater: periosteal layer
equivalent to the periosteum of cranial bones
29
dura mater: meningeal layer
continues into vertebral canal and forms the dural sheath around the spinal cord
30
dural sinues
spaces located where periosteal and meningeal layers separate
31
_____ _____ _____ and _____ _____ collect blood circulating through the brain
superior sagittal sinus, transverse sinus
32
where is the dura mater attached to bone? (4)
- foramen magnum
- sella turcica
- crista galli
- sutures of the skull
33
falx cerebri
separates the two cerebral hemispheres
34
tentorium cerebelli
separates cerebrum from cerebellum
35
falx cerebelli
separates left and right halves of the cerebellum
36
arachnoid mater
transparent membrane over the brain surface
37
the _____ _____ separates the arachnoid mater from the pia mater below it
subarachnoid space
38
the subarachnoid space is filled with _____ _____ and blood vessels
cerebrospinal fluid
39
pia mater
very thin membrane, not usually visible without a microscope that is on the surface of the brain/spinal tissue
40
characteristics of the pia mater (2)
- follows the contours of the brain
- follows arteries as they penetrate into the cerebrum
41
meningitis
inflammation of the meninges; serious disease of infancy and childhood
42
what is meningitis caused by?
bacterial or viral invasion of the CNS through the nose and throat, mostly affecting the pia and arachnoid mater
43
what are signs and symptoms of meningitis? (7)
- swelling of the brain
- enlargement of the ventricles
- hemorrhage
- high fever
- stiff neck
- drowsiness
- intense headache
44
how do they diagnose meningitis?
examining the cerebral spinal fluid obtained by lumbar puncture (spinal tap)
45
ventricles
four internal, fluid-filled chambers of the brain
46
lateral ventricles
one in each cerebral hemisphere
47
third ventricle
narrow medial space beneath corpus callosum
48
fourth ventricle
small triangular chamber between pons and cerebellum
49
interventricular foramen
pore that connects lateral ventricles to the third ventricle
50
cerebral aqueduct
tube running through the midbrain that connects third ventricle to the fourth ventricle
51
central canal
tube that connects to the fourth ventricle and runs through the center of the spinal cord
52
cerebrospinal fluid (CSF)
clear, colorless liquid that fills the ventricles, canals of the CNS and bathes its external surface
53
ependymal cells
neuroglia that line ventricles and cover the choroid plexus; produce CSF
54
how does the production of CSF begin?
filtration of blood plasma through capillaries of the brain
55
what happens after blood plasma is filtered for CSF?
ependymal cells modify the filtrate; compared to plasma, CSF has more sodium and chloride, less potassium, calcium, glucose, and very little protein
56
choroid plexus
spongy mass of blood capillaries on the floor of each ventricle
57
how is CSF pushed through the CNS?
driven by its own pressure, beating of ependymal cilia, and pulsation of the brain produced by each heartbeat
58
CSF path through the ventricles (4)
1. secreted in lateral ventricles
2. through the intervertebral foramina into the third ventricle
3. down the cerebral aqueduct into the fourth ventricle
4. third and fourth ventricles add more CSF along the way
59
all CSF ultimately escapes through _____ pores that lead into the _____ _____ of the brain and spinal cord surface
three, subarachnoid space
60
what are the three pore CSF escapes through
- median aperture
- two lateral apertures
61
CSF is reabsorbed by _____ _____, extensions of the arachnoid meninx
arachnoid granulations
62
arachnoid granulations
extensions of the arachnoid meninx that protrude through the dura mater into the superior sagittal sinus
63
functions of the CSF: buoyancy
- allows brain to attain considerable size without being impaired by its own weight
- if brain rested on the cranium floor, pressure would kill the nervous tissue
64
functions of the CSF: protection
- protects brain from striking cranium when head is jolted
- shaken baby syndrome and concussion still occur from severe jolting
65
functions of the CSF: chemical stability
- flow of CNS rinses away metabolic wastes from nervous tissue and homeostatically regulates the chemical environment
66
the brain is supplied with blood by the _____ _____ _____ and _____ _____
internal carotid arteries, vertebral arteries
67
brain barrier system (BBS)
regulates what substances can get from the bloodstream into the tissue fluid of the brain
68
the brain barrier system is selectively permeable...
highly permeable to water, glucose, amd lipid-soluble substances like oxygen, CO2, alcohol, caffein, nicotine, and anesthetics
slightly permeable to sodium, potassium, chloride, wate products like urea, and creatinine
69
two points of entry to the brain must be guarded:
- blood capillaries throughout the brain tissue, guarded by the blood-brain barrier
- capillaries of the choroid plexus, guarded by the blood-CSF barrier
70
blood-brain barrier
protects the brain at the blood capillaries
consists of tight junctions between endothelial cells that form the capillary walls
71
blood-CSF barrier
protects the brain at the choroid plexus
formed by tight junctions between ependymal cells
72
stroke (cerebral vascular accident, CVA)
sudden death of brain tissue due to interruption of blood supply; second greatest cause of death
73
hemorrhagic stroke
rupture of a cerebral or subarachnoid blood vessel
74
ischemic stroke
obstruction of a blood vessel by a blood clot of lipid deposit
75
medulla oblongata
adult brain region that develops from embryonic myelencephalon
76
functions of the medulla oblongata (5)
- relays info to/from the brain and spinal cord
- coordinates complex autonomic reflexes
- controls visceral functions
- contains autonomic centers that control heart rate, blood pressure, respiration, and reflexes
- contains sensory and motor nuclei for cranial nerves
77
pons
adult brain region that develops from the embryonic metencephalon
78
characteristics of the pons (4)
1. sensory and motor nuclei of cranial nerves V, VI, VII, and VIII
2. nuclei involved with respiration
3. nuclei that process and relay information to and from the cerebellum
4. ascending, descending, and transverse tracts link nuclei of pons with the opposite cerebellar hemisphere
79
_____ _____ and _____ _____ function to modify respiratory rhythmicity
apneustic center, pneumotaxic center
80
the _____ _____ in the pons contains additional nuclei concerned with sleep, respiration, and posture
reticular formation
81
midbrain
brain region that develops from the embryonic mesencephalon; short segment of the brainstem that connects hindbrain to forebrain
82
midbrain: cerebral aqueduct
surrounded by central (periaqueductal) gray substance involved in pain awareness
83
tectum
roof-like part of the midbrain posterior to cerebral aqueduct
84
tectum: superior colliculi
two; visual attention, tracking moving objects, and visual reflexes
85
tectum: inferior colliculi
two; relays signals from inner ear to thalamus and other parts of the brain, auditory reflexes
86
tegmentum
connections go to and from the cerebellum for motor control
87
substantia nigra
dark nucleus pigmented with melanin; motor center that relays inhibitory signals to thalamus and basal nuclei, suppressing unwanted body movements
88
reticular activating system (RAS)
component of the reticular formation in the midbrain important for alertness and attentiveness
89
habituation
when the RAS modulates activity in the cerebral cortex so that it ignores repetitive, inconsequential stimuli
90
the reticular formation also has the following functions (2)
pain modulation, and sleep and consciousness
91
an injury here can cause an irreversible coma
reticular activating system
92
cerebellum
largest part of hindbrain; second-largest part of the brain as a whole; contains more than half of all brain neurons
93
granule cells
found in cerebellum; most abundant type of neuron in the entire brain
94
purkinje cells
large cerebellar neurons: axons project to deep nuclei to synapse with neurons that lead to the brainstem
95
the right and left _____ _____ are connected by a bridge called the _____
cerebellar hemispheres, vermis
96
folia
superficial cortex of grey matter with folds; cerebellum
97
abor vitae
branching white matter of the cerebellum
98
functions of the cerebellum (2)
- motor coordination and locomotor ability
- sensory, linguistic, emotional, and other non-motor functions
99
ataxia
clumsy, awkward gait
100
damage to what portion of the brain can cause ataxia?
cerebellum
101
diencephalon had three major components
- thalamus
- hypothalamus
- epithalamus
102
damage to what portion of the brain causes desynchronization between hemispheres and can lead to epilepsy/seizures?
thalamus
103
what does the thalamus do?
synchronizes electrical activity between the two cerebral hemispheres
104
thalamus: gateway to the cerebral cortex
- nearly all input to the cerebrum synapses in thalamic nuclei
- processes information on its way to the cerebral cortex
- not all info passes along; thalamus screens out most of the info it receives
105
thalamus: key role in motor control
- relays signals from the cerebellum to cerebrum
- provides feedback loops between cerebral cortex and basal nuclei
106
thalamus: involved in memory and emotion
limbic system includes some of the anterior thalamic nuclei
107
hypothalamus
forms part of the walls and floor of the third ventricle; extends anteriorly to the optic chiasm and extends posteriorly to mammillary bodies; processes olfactory and other sensory info and controls reflex eating movements
108
the hypothalamus attaches to the _____ _____ through a stalk-like structure called the _____
pituitary gland, infundibulum
109
the major control center of autonomic nervous system and endocrine system
hypothalamus
110
seven functions of the hypothalamic nuclei
1. hormone secretion
2. autonomic effects
3. thermoregulation
4. food and water intake
5. sleep and circadian rhythms
6. memory
7. emotional behavior and sexual response
111
hypothalamic nuclei: hormone secretion
- controls anterior pituitary, thereby regulating growth, metabolism, reproduction, and stress responses
- produces posterior pituitary hormones for labor contractions, lactation, and water conservation
112
hypothalamic nuclei: autonomic effects
- major integrating center for autonomic nervous system
- influences heart rate, blood pressure, gastrointestinal secretions, mobility, etc.
113
hypothalamic nuclei: thermoregulation
hypothalamic thermostat monitors body temperature, activates mechanisms to adjust temperature if necessary
114
hypothalamic nuclei: food and water intake
- regulates hunger and satiety; responds to hormones influencing hunger, energy expenditure, and long term control of body mass
- osmoreceptors monitor osmolarity of the blood, and can stimulate production of antidiuretic hormone (ADH) to help conserve water
115
hypothalamic nuclei: sleep and circadian rhythms
suprachiasmatic nucleus controls 24-hour rhythm
116
hypothalamic nuclei: memory
mammillary nuclei relay signals from hippocampus to thalamus
117
hypothalamic nuclei: emotional behavior and sexual response
anger, aggression, fear, pleasure, contentment, sexual drive
118
pineal gland
an endocrine gland located in the epithalamus; produces/secretes the hormone melatonin which is important in the day/night cycle and reproductive function
