brain (major structures and functions) Flashcards
1
Q
what does the CNS first start out as? (brain embryology)
A
the neural tube
2
Q
what is the lumen of the neural tube?
what is it filled with?
what does it become?
A
- neurocoel
- fluid
- eventually forms the brains ventricles
3
Q
what 3 regions form at 4 weeks?
A
- prosencephalon
- mesencephalon
- rhombencephalon
4
Q
what does the prosencephalon form?
A
- telencephalon
- diencephalon
5
Q
what does the telencephalon form?
A
the cerebrum and the lateral ventricle
6
Q
what does the diencephalon form?
A
the hypothalamus, thalamus, and the epithalamus
also the third ventricle
7
Q
what does the mesencephalon form?
A
it becomes the midbrain
8
Q
what does the rhombencephalon form?
A
- metencephalon
- myelencephalon
9
Q
what does the metencephalon form?
A
the pons and cerebellum
10
Q
what does the myelencephalon form?
A
the medulla oblongata
11
Q
what are the major regions of the brain? (6)
A
- medulla
- pons
- midbrain
- diencephalon
- cerebellum
- cerebrum
12
Q
general functions of the medulla oblongata
A
- relays info to the thalamus and the brainstem
- HR, BP, and digestion regulation
13
Q
general functions of the pons
A
- relays info to the cerebellum and the thalamus
- somatic and visceral motor center regulation
14
Q
pons (professor’s notes)
A
contains higher respiratory control centers
- apneustic
- pneumotaxic
15
Q
apneustic pons
A
inhibits exhalation for inhalation
16
Q
pneumotaxic pons
A
inhibits inhalation for exhalation
17
Q
medulla (prof’s notes)
A
the medulla relays communication between the midbrain and the cerebellum
ex… you can’t maintain balance if your eyes are closed
balance = comes from cerebellum
eyes closed = comes from superior colliculi
18
Q
general functions of the mesencephalon (midbrain)
A
- processes visual and auditory data
- maintains consciousness
- helps with reflexive somatic motor responses
visual = superior colliculi
auditory = inferior colliculi
19
Q
midbrain (prof’s notes)
A
the reticular formation of the midbrain helps with maintaining consciousness
ex… when we’re walking down a dark alley and we’re scared, we become very alert
this is also an example of reverberation
20
Q
general functions of the diencephalon
A
contains…
1. thalamus
2. epithalamus
3. hypothalamus
21
Q
thalamus functions
A
- relays info from the cerebrum
- center for sensory information relaying
the spinothalamic tract runs through here
22
Q
epithalamus functions
A
- contains the pineal gland
the pineal gland secretes hormones like melatonin and controls the secretion of FSH and LH from the pituitary gland
23
Q
hypothalamus functions
A
- involved in emotions, thirst, and habitual activity
- involved in temperature control
- involved in circadian rhythm control
24
Q
circadian rhythm control (prof’s notes)
A
in the morning, melatonin decreases and cortisol increases
the opposite is true for when you go to sleep
25
hypothalamus (prof's notes)
the hormones released by the hypothalamus often control the release of hormones of the anterior pituitary gland
ex... corticotropic releasing hormone from the hypothalamus controls the release of cortisol from the ant. pituitary gland
26
general functions of the cerebellum
1. coordinates complex somatic motor patterns
2. adjustment of somatic motor centers for smooth movement
27
cerebellum (prof's notes)
this basically controls balance and coordination
ex... to test balance, have one walk in a straight line
recall that communication with the corpus quadrigemina is maintained by the medulla
this also contains the vasomotor center (VMC) for blood vessel diameter control
28
general functions of the cerebrum
1. conscious SKM regulation
2. conscious thought
3. intellectual thinking
4. memory
29
cerebrum (prof's notes)
contains the cortex which is grey matter
the junction between the grey and white matter are the pyramidal cells
the hippocampal gyrus is responsible for memory
30
what is the function of the ventricular system of the brain?
to filter and move CSF which brings nutrients and removes waste from the CNS
31
the 4 brain ventricles
1. lateral ventricles (2x)
2. third ventricle
3. fourth ventricle
32
septum pellucidum
separates the 2 lateral ventricles
33
lateral ventricle horns
1. anterior horn
2. posterior horn
3. inferior horn
34
pathway of CSF through ventricles
1. CSF is made by the choroid plexus
2. CSF is in the lateral ventricles
3. goes through interventricular foramen to the third ventricle
4. goes through the cerebral aqueduct to the fourth ventricle
35
fourth ventricle to the spinal cord
the lateral and median apertures let CSF into the subarachnoid space which CSF then enters the central canal
36
what are the two layers of the dura mater?
1. endosteal
2. meningeal
these layers surround the dural sinus
the endosteal layer is directly attached to the skull
37
what are the four dural folds?
1. falx cerebri
2. tentorium cerebelli
3. falx cerebelli
4. diaphragma sellae
38
what does the falx cerebri separate?
it separates the two hemispheres of the cerebrum by folding into the longitudinal fissure
39
what does the tentorium cerebelli separate?
it separates the cerebrum from the cerebellum by folding into the transverse fissure
40
what does the falx cerebelli separate?
it separates the two cerebellar hemispheres
41
what does the diaphagma sellae separate
it protects the pituitary gland from in the sella turcica
42
what do the arachnoid granulations do?
they maintain CSF volume and pressure by dumping excess CSF into the dural veinous sinuses
veinous sinuses bring blood to the jugular vein
43
high CSF pressure pathology (prof's notes)
high CSF pressure presents with projectile vomiting, headaches and blurry vision
these are signs of meningitis
44
what can pass through the blood brain barrier?
1. lipid soluble material
2. 3rd generation antibiotics
45
the BBB is continuous throughout the brain except for the following three areas?
1. parts of the hypothalamus
2. pineal gland
3. parts of the 3rd and 4th ventricles
46
what are medulla's relay functions?
since the medulla is continuous with the brain stem and spinal cord, all communication passes through the medulla
47
what are the 5 cranial nerves that innervate the medulla
CN's 8, 9, 10, 11, and 12
*the cochlear branch of CN 8 only
12 = hypoglossus
11 = accessory
10 = vagus
9 = glossopharyngeal
8 = vestibulocochlear
48
what are the nuclei relay stations of the medulla
1. olivary nuclei --> cerebellum relay
2. nucleus gracilis and nucleus cuneatus --> somatic sensory relay to thalamus
49
what is the pyramidal decussation
the pyramids of the medulla is the region of cross over form motor neurons
50
what are the major reflex centers of the medulla? (think HR and RR)
1. cardiovascular centers
2. respiratory centers
51
what are the two cardiovascular centers?
1. CIC (inhibitor)
2. CAC (accelerator)
both centers provide nervous system control to increase or decrease the heart rate
52
what cranial nerves innervate the pons? (4x)
CN's 5, 6, 7, and 8
5 = trigeminal
6 = abducens
7 = facial
8 = vestibular branch
53
what do cerebellar peduncles do?
they are the nuclei of the pons that relays to the cerebellum
54
aside from the corpus quadrigemina (superior and inferior colliculi) what else is part of the mesencephalon (midbrain)
1. red nucleus
2. substantia nigra
3. cerebral peduncles
55
red nucleus function
integrates info between the cerebrum and cerebellum
56
substantia nigra function
regulates motor output of the basal nuclei
this tissue can affected in parkinsons
57
cerebral peduncles
consists of ascending and descending fibers (think spinothalamic and corticospinal)
58
substantia nigra and parkinsons
the substantia nigra controls muscle tone and fine movement which can affected by parkinsons
59
what does the hypothalamus consist of?
1. the infundibulum (pituitary stalk)
2. mammillary body
60
what does the hypothalamus do?
1. subconscious SKM control
2. HR, BP, RR, and digestive control
3. secretion of hormones (supraoptic nucleus)
4. emotion
5. behavior
6. thirst
7. temp control
8. circadian rhythm (suprachiasmatic nucleus)
61
what is the function of the mamillary bodies?
they are involved in feeding control
ex... swallowing, licking ice cream
62
what are the structures and contents of the cerebellum?
1. vermis
2. folia
3. arbor vitae
4. purkinje cells
63
what are purkinje cells?
these are cells analogous to the pyramidal cells of the cerebrum
they are at the junction between grey and white matter
64
what are the 3 cerebellar peduncles?
each cerebellar peduncle facilitates cerebellum communication with different parts of the brain stem
1. superior --> to the midbrain
2. middle --> to the pons
3. inferior --> to the medulla
65
what lies behind the lateral sulcus?
the insula which processes taste and smell
66
what does the frontal lobe do?
controls SKM
67
what does the occipital lobe do?
the occipital lobe perceives visual stimuli
68
what does the parietal lobe do?
perceives touch, pressure, vibration, pain, temp and taste
69
what does the temporal lobe do?
perceives visual and auditory stimuli
70
what does the cerebral cortex do?
the cerebral cortex maintains higher order functions of the left and right cerebral hemispheres
specifically it integrates sensory stimuli and motor responses
71
what are the noteable centers of the cerebrum
1. general interpretive area
2. speech center (Broca and Wernicke)
3. prefrontal cortex
4. brodmann's area
72
what does the general interpretive area do?
the general interpretive area is present on the left cerebral hemisphere and is the analytical center
73
what does wernicke's area do?
wernicke's area helps us discern spoken language
ex... I can distinguish that someone is talking to me in english
74
what does broca's area do?
broca's area regulates breathing patterns and speech vocalization
75
what does the prefrontal cortex do?
the prefrontal cortex performs complicated learning and reasoning functions
76
what are the 3 fiber types of the central white matter that connect the cerebrum and other parts of the brain?
1. association fibers
2. commissural fibers
3. projection fibers
77
association fibers
includes arcuate and longitudinal fibers that connect different lobes together
78
commissural fibers
includes the anterior commissure which connects the two cerebral hemispheres
79
projection fibers
fibers that link the cerebrum to other parts of the brain and spinal cord
80
what are the basal nuclei?
this is grey matter imbedded in the white matter
general functions include..
1. SKM tone control
2. learned movement pattern coordination
3. info processing, integration and relay from the cerebral cortex
81
examples of basal nuclei
1. globus pallidus
2. putamen
3. amygdaloid body --> initiates fear
4. caudate nucleus
5. claustrum
82
caudate nucleus, putamen, globus pallidus function
controls arm and leg cycles when walking
83
claustrum function
subconscious processing of visual information
84
amygdaloid body
part of the limbic system, initiates emotions such as fear
85
what is the function of the limbic system?
it's primary function is for memory storage and retrieval, it can also establish emotional states
structures to note...
1. hippocampus
2. parahippocampal gyrus
3. cingulate gyrus
4. fornix
86
taxi driver example
since the limbic system is involved in memory storage, UK taxi drivers were found to have large hippocampuses because they need to memorize routes in the UK
87
