Lecture 3 Flashcards
1
Q
OVERVIEW
A
OVERVIEW
2
Q
The brain has ____ billion neurons and ___ trillion neuroglia.
A
- 100
- 1
3
Q
What is the order of brain development?
A
- ectoderm
- neural fold
- neural tube
- 3 primary vesicles
- 5 secondary vesicles
4
Q
What are the 5 secondary vesicles and what structures are located in them?
A
- Telencephalon= cerebral hemispheres, basal ganglia, limbic system
- Diencephalon= thalamus, hypothalamus, epithalamus
- Mesencephalon (midbrain)= cerebral peduncles, corpus quadrigemina
- Metencephalon= cerebellum, pons
- Myelencephalon= medulla oblongata
5
Q
Ascending sensory signals going to the telencephalon have to cross the others, what does this result in?
A
Other structures have the potential to modify the signals (descending motor signals act the same way)
6
Q
List the correct order of the protective coverings of the brain.
A
- SCALP= skin, connective tissue, aponeurosis, lipid, periosteum
- cranial bones= skull
- epidural space
- dura mater
- subdural space
- arachnoid mater
- subarachnoid space
- pia mater
7
Q
Which of the spaces has interstitial fluid?
Which space has CSF?
A
- subdural space
- subarachnoid space
8
Q
What are the 3 folds of the dura mater that hold the brain in place and their location?
A
Falx Cerebri -sagittal between cerebral hemispheres Falx Cerebelli -sagittal between cerebellar hemispheres Tentorium Cerebelli -transverse between cerebrum and cerebellum
9
Q
Are there sinuses associated with these folds?
A
Yes, allowing blood to drain
10
Q
The brain is a fuel hog, it is __% of the total body weight, but uses __% of the bodies O2 and glucose when it is resting.
A
- 2%
- 20%
11
Q
What does the brain normally use as a fuel source?Is it able to store it?
A
- glucose
- no
12
Q
What are the 3 parts of the BBB?
A
- tight junctions
- continuous endothelial cell basement membrane
- astrocytes (neuroglia)
13
Q
The BBB is selective for the passage of _____ soluble substances but allows free passage of ______ soluble substances into the brain.
A
- water
- lipid (hydrophobic)
14
Q
What are the 3 organs that don’t have the BBB?
What are they collectively called?
A
- hypothalamus, pituitary, pineal gland
- circumventricular organs
15
Q
BRAIN STEM OVERVIEW
A
BRAIN STEM OVERVIEW
16
Q
What are the 3 parts of the brain stem?
A
- myelencephalon (medulla oblongota)
- pons
- mesencephalon (midbrain)
17
Q
The medulla oblongota contains both ________ ascending and ________ descending tracts.
A
- sensory
- motor
18
Q
The medulla oblongata pyramids are paired ventral surface ridges that contain what tracts?
A
motor descending
19
Q
What does the decussation of pyramids seperate and what is its function?
A
- seperates the spinal cord from the medulla
- function is carrying the corticospinal tracts which carry motor impulses from the motor cortex to the spinal cord (this is where cross over to control the opposite side of the body occurs)
20
Q
What are the paired bulges lateral to pyramids which contain the inferior olivary nuclei? What is its function?
A
- olives
- links brain and spinal cord motor signals to the cerebellum for the perception of time
- proprioception, hearing
21
Q
The dorsal medulla contains the fasciculus gracilis and the fasciculus cuneatus which do what?
A
- fasciculus gracilis-carries sensory information from the lower limbs
- fasciculus cuneatus-carries sensory information from the upper limbs and torso
22
Q
What is the decussation of the medial lemniscus?
A
the crossover of ascending sensory input to the contralateral brain hemisphere
23
Q
The medulla oblongata has nuclei perform vital body functions but also has nuclei for what cranial nerves?
A
CN8-CN12
24
Q
What is the overall function of the medulla oblongata?
A
- nuclei for vital centers and cranial nerves(including respiration, cardiac function, vasodilation, and reflexes like vomiting, coughing, sneezing, and swallowing)
- signal propogation via ascending and descending tracts
25
The pons has nuclei for ascending and descending tracts, but also has nuclei for what cranial nerves?
CN5-CN7
26
What is the function of the pons?
information relay for cerebellar hemispheres
27
What are the structures found in the midbrain?
- cerebral peduncles
- corpora quadrigemina (superior and inferior colliculi)
- nuclei for CN3 and CN4
- red nucleus and substantia nigra
28
The midbrain contains cerebral peduncles which contain what?
- descending motor axon tracts from cerebral hemispheres to spinal cord, medulla, and pons
- ascending sensory axons going to the cerebrum
- PRIMARILY MOTOR
29
What are the parts of the corpora quadrigemina and their function?
- 2 superior colliculi- reflex movement of eye, head, and neck to visual and other stimuli
- 2 inferior colliculi- reflex movement of head and neck to auditory stimuli
30
The midbrain has nuclei for what cranial nerves?
CN3 and CN4
31
What is the function of the red nucleus and the substantia nigra?
modify motor signals (coordination)
32
What are the 2 main functions of the midbrain?
- relay motor impulses from cerebral cortex
| - relay sensory impulses from spinal cord to thalamus
33
The reticular formation is composed of gray matter interspersed among areas of white matter in central portions of what?
- diencephalon
- brain stem
- spinal cord
34
What are the main functions of the reticular formation?
- alerting cerebral cortex to sensory signals
- the reticular activating system functions in maintaining consciousness and awakening from sleep by stimulating the cortex
- filters sensory input to remove unimportant input
35
CEREBELLUM (METENCEPHALON)
CEREBELLUM (METENCEPHALON)
36
The cerebellum is composed of _ ventricles that are connected by what?
What else is located in the cerebellum?
- 2
- vermis
- peduncles
37
The _______ is the gray matter of the cerebellum, and the _________ is the white matter of the cerebellum.
- cortex
| - arbor vitae
38
What are the ridges on the cerebellum called?
folia
39
The cerebellar nuclei are gray matter scattered in what?
arbor vitae (white matter)
40
What are the 3 main functions of the cerebellum?
- coordinate cerebral control of skeletal muscle movements
- regulate muscle tone
- posture and balance
41
DIENCEPHALON
DIENCEPHALON
42
What are the 4 parts of the diencephalon?
- thalamus
- hypothalamus
- epithalamus
- subthalamus
43
What are the main functions of the thalamus?
- sensory relay to the correct region of the cerebral cortex
| - refine motor signals with the basal nucleus
44
The R and L thalamus is seperated by what?
3rd ventricle
45
What is the overall function of the hypothalamus?
Maintain homeostasis
46
The hypothalamus controls ________ nervous system, _______ system, and body ___________.
- autonomic NS (heart, gut, bladder)
- endocrine (via control of pituitary)
- temperature
47
The hypothalamus regulates _______ behavior (limbic system), ______ and _________, and ________ rhythms and states of consciousness.
- emotional
- eating and drinking
- circadian rhythms
48
All of the functions of the hypothalamus are somewhat _______ _________.
unconscious involuntary
49
The hypothalamus has __ nuclei.
11 (dozen)
50
What is visible on the anterior surface of the hypothalamus?
mamillary bodies
51
What structure connects the pituitary to the hypothalamus
infundibulum
52
The epithalamus is composed of what 2 structures?
| What are their functions?
- pineal gland- melatonin production to set biological clock
| - habenular nuclei- emotional response to smell
53
The subthalamus is composed of what 3 structures?
- subthalamic nuclei (paired)
- parts of red nuclei (paired)
- parts of substantia nigra (paired)
54
What is the function of the subthalamus?
refines movement and is important for motor control
55
CIRCUMVENTRICULAR ORGANS
CIRCUMVENTRICULAR ORGANS
56
What are the 3 circumventricular organs? What is their function?
- hypothalamus, pituitary, pineal
| - internal sensory system to maintain homeostasis
57
What do the circumventricular organs not have?
BBB
58
BASAL GANGLIA (TELENCEPHALON)
BASAL GANGLIA (TELENCEPHALON)
59
What is the function of the basal ganglia?
- control of skeletal muscle movement and muscle tone
| - refine motor responses, making movements smoother
60
LIMBIC SYSTEM (TELENCEPHALON, DIENCEPHALON)
LIMBIC SYSTEM (TELENCEPHALON, DIENCEPHALON)
61
The limbic system is the "________" brain and functions in _______ aspects of behavior and memory-pain, pleasure, affection, and anger to determine ________.
- primitive
- emotional
- feelings
62
CEREBRUM (TELENCEPHALON)
CEREBRUM (TELENCEPHALON)
63
The cerebral cortex of the cerebrum is composed of ____ matter
gray
64
What are the 3 types of neurons found in the white matter of the cerebrum?
- association fibers
- commissural fibers
- projection fibers
65
Association fibers connect different gyri in _____ hemisphere.
same
66
Commissural fibers connect different gyri in ________ hemisphere.
opposite
67
Projection fibers connect the cerebrum to rest of the body (_______ and ______ tracts)
sensory and motor
68
The cerebrum is the highest of the brain regions and functions in what?
- conscious sensation (receives input)
- voluntary motor (sends output)
- higher brain function is cognition (association of sensory input with memory to produce more memory, language, abstract thought... humanity)
69
Difference between gyri and sulci?
- gyri=ridges (mountain)
| - sulci=grooves (valley)
70
What is the difference between a sulcus and a fissure?
- sulcus=groove
| - fissure=deep groove (divides into lobes and hemispheres)
71
The corpus callosum is a large connection of commissural tracts that do what?
connect the right and left hemisphere
72
What are the 5 lobes of the cerebrum?
- Frontal
- Parietal
- Temporal
- Occipital
- Insula
73
The central sulcus seperates the _______ and _________ lobes.
frontal and parietal
74
The precentral gyrus is _________ to the central sulcus and is a ________ ______ area.
- anterior
| - voluntary (somato-) motor area
75
The postcentral gyrus is __________ to the central sulcus and is a _______ ________ area.
- posterior
| - conscious (somato-) sensory area
76
The lateral cerebral fissure seperates ________ and _________ lobes.
frontal and temporal
77
The parieto-occipital sulcus seperates _______ and ________ lobes
parietal and occipital
78
The frontal lobe is located anterior of ________ sulcus and medial to _______ sulcus and contains the ___________ gyrus.
- central
- lateral
- precentral gyrus
79
The precentral gyrus is the primary ______ cortex controlling ________ movement on the ___________ side of the body.
- motor
- voluntary
- contralateral
80
What is meant by somatotopic?
specific regions of the precentral gyrus control muscles in specific body regions
81
What is the homonculus?
depicts somatotopic organization of precentral gyrus and relative cortical contributions to a particular body region
82
The premotor area, also known as the __________ motor area is the associative area next to the precentral gyrus that functions to do what?
- supplementary motor area
| - initiate and sequence motor activity
83
The frontal eye field is a part of the ______ lobe that functions to do what?
- frontal
| - conjugate eye movements (coordinate L and R)
84
What structure in the frontal lobe coordinates motor speech?Is it in both hemispheres?
- Broca's area
| - No, only in left hemisphere
85
The _______ cortex is the most rostral part of the frontal lobe and is the primary target of lobotomy.
-prefrontal
86
The prefrontal cortex recieves input from all regions of the cortex and limbic system and functions to regulate what?
-visceral, emotional (limbic) with memory, and cognitive processes
87
What is the cingulate gyrus?
- Curved fold covering the corpus callosum in the longitudinal fissure of the frontal and parietal lobes.
- Functions as part of the limbic system for emotional behavior but also performs autonomic response and learning.
88
The insula is located within the _______ sulcus where frontal, parietal, and temporal lobes come together. It functions in integration of sensory input for what?
-lateral
- taste and olfaction
- viscerosensation
- pain
89
The parietal lobe is located _________ of the central sulcus and contains the ______ gyrus.
- posterior
| - postcentral gyrus
90
The post-central gyrus is the primary ________ area for _______ and proprioceptive sensation.
- sensory
| - tactile
91
The post-central gyrus, like the precentral gyrus has a homunculus, which is what?
depicts somatotopic organization of post-central gyrus and relative cortical contributions to a particular body region
92
What are two other gyrus found in the parietal lobe and what do they do?
-supramarginal and angular-recieve visual and auditory input for perceptional discrimination, and integration
93
What structure in the parietal lobe functions in comprehension of speech?
Is it in both hemispheres?
- Wernicke's Area
| - No, located in left hemisphere of parietal and temporal lobes
94
__________ and _______ function together to form verbal responses.
Wernicke's Area and Broca's Area
95
The occipital lobe is located caudal to what sulcus?
parieto-occipital sulcus
96
What are the 2 parts of the occipital lobe?
- primary visual cortex
| - visual association cortex (secondary)
97
What are the 5 gyrus of the temporal lobe and their function?
Transverse gyri of Heschl
-medial aspect of superior temporal gyrus
-primary auditory cortex
Superior Temporal Gyrus
-auditory association cortex
Middle Temporal Gyrus
-perception and analysis of motion in the visual field
Inferior Temporal Gyrus
-facial recognition in response to visual input
Parahippocampal Gyrus and Uncus
-located on the inferior surface of temporal lobe
-function with the limbic system
98
The cerebrum is divided into 2 hemispheres seperated by what? Connected by what?
- longitudinal fissure
| - commissural fibers
99
What is hemispheric localization?
functional differences exist between hemispheres = cerebral dominance
100
What is the difference in function of the left and right hemispheres?
```
Left Hemisphere
-language interpretation and execution
-numerical and scientific skills
-reasoning
Right Hemisphere
-musical, artistic-facial recognition
-emotional content of language
```
101
Cerebral dominance is due to what 2 reasons?
- unequal cortical representation
| - diminished commissural cross connections
102
ARTERIAL BLOOD SUPPLY TO BRAIN
ARTERIAL BLOOD SUPPLY TO BRAIN
103
Go through the origin of the right internal carotid artery.
- left ventricle
- ascending aorta
- brachiocephalic artery
- right common carotid
- right internal carotid
104
Go through the origin of the left internal carotid artery.
- left ventricle
- ascending aorta
- aortic arch
- left common carotid
- left internal carotid
105
Go throught the origin of the right vertebral artery.
- left ventricle
- ascending aorta
- brachiocephalic artery
- right subclavian
- right vertebral
106
Go through the origin of the left vertebral artery.
- left ventricle
- ascending aorta
- aortic arch
- left subclavian
- left vertebral
107
What is the course of the internal carotid through the skull?
- external opening of carotid canal in temporal bone
- carotid canal in petrous portion of temporal bone
- internal opening of carotid canal in temporal bone
- crosses over foramen lacerum
- runs along base of sella turcica in carotid groove
- turns up to join optic nerve at prechiasmatic groove
108
What are the branches of the internal carotids proximal to distal and what do they supply?
- opthalmic a. = choroid/retina via central a. of retina
- posterior communicating a. = diencephalon
- anterior choroidal a. = telencephalon deep structures
- anterior cerebral a. = medial frontal and parietal lobes
- middle cerebral a.
109
The opthalmic artery runs with CN_ supplying blood to the choroid/retina of the eye via ________ artery of the retina.
- 2
| - central
110
The posterior communicating artery is a part of the _____________ supplying the ____________.
- circle of Willis
| - diencephalon
111
The anterior choroidal artery arises near the middle cerebral artery to supply deep structures of the _____________.
telencephalon
112
The anterior cerebral artery (ACA) runs in the __________ fissure above the corpus callosum to the medial aspect of ________ and ___________ lobes.
- longitudinal
| - frontal and parietal
113
What body regions and function would be affected by a stroke lesion at the anterior cerebral artery?
- lower extremity
| - cognitive function
114
What does the anterior communicating artery connect?
connects R and L anterior cerebral arteries
115
Other branches of the anterior cerebral artery feeds deep structures of __________.
telencephalon
116
The middle cerebral artery (MCA) runs in the ______ sulcus to what lobes?
-lateral sulcus
- lateral frontal
- lateral parietal
- insula
- lateral occipital
- medial and lateral temporal
- subcortical deep structures
- basal ganglia
- internal capsule
- limbic structures
117
What is the course of the vertebral arteries?
- transverse foramen of cervical vertebrae
- from C1 bends medial to foramen magnum
- passes through foramen magnum
- ascends clivus
- R and L vertebrals fuse into basilar artery
118
What are the branches of the vertebral artery from proximal to distal?
- anterior spinal a.
- posterior inferior cerebellar a.
- posterior spinal a.
119
What does the anterior spinal a. supply?
Medial medulla (pyramids, medial lemniscus, MLF)
120
What does the posterior inferior cerebellar a. supply?
Lateral medulla (spinothalamc tract, spinocerebellar tract, spinal nuc. of CN5)
121
What does the posterior spinal a. supply?
Dorsal medial medulla (cuneatus and gracilis)
122
What are the branches of the basilir a. from proximal to distal?
- anterior inferior cerebellar a.
- labyrinthine a.
- pontine a.
- superior cerebellar a.
- posterior cerebral a.
123
What does the anterior inferior cerebellar a. supply?
cerebellum and pons
124
What does the labyrinthine a. supply?
enters internal acoustic meatus to cochlea and vestibular apparatus
125
What do the pontine a. branches supply?
pons
126
What does the superior cerebellar a. supply?
cerebellum, pons, and midbrain
127
What does the posterior cerebral a. supply?
Cortex-medial (primary visual) and inferior occipital, inferior temporal
Subcortical structures-midbrain, subthalamus, and thalamus
128
The Circle of Willis is an anastamosis between what two arteries?
- basilir
| - internal carotid
129
List the structures making up the Circle of Willis.
- anterior communicating a.
- anterior cerebral a.
- meets up w/ middle cerebral a.
- posterior communicating a.
- posterior cerebral a.
130
The middle meningeal artery goes through what opening?
foramen spinosum
131
Describe the direction of venous drainage of the brain.
- superior and inferior sagittal sinuses along with occipital sinus drain into confluence of sinuses
- confluence of sinuses drains into transverse sinus
- transverse sinus drains into sigmoid sinus
- sigmoid sinus drains into internal jugular vein
132
SPINAL CORD
SPINAL CORD
133
The spinal cord runs from the medulla oblongata to L1/L2 ending in ___________________.
conus medullaris
134
There are ___ pairs of spinal nerves, _ cervical, __ thoracic, __ lumbar, __ sacral, __ coccygeal.
-31-8-12-5-5-1
135
Dorsal roots= _______ axons
| They can be either __________ sensory or ________ sensory.
- sensory
- somato
- viscero
136
Somatosensory neurons are for ____ and __________ medially. They are for _____ and _________ laterally.
- touch and proprioception
| - pain and temperature
137
Ventral roots= _______ axons
| They can be either ________ motor or ________ motor
- motor
- somato
- autonomic (viscero)
138
The spinal nerve exit the spinal cord via ____________ foramen
intervertebral
139
What are the boundaries of the intervertebral foramen?
- sup and inf pedicles
- body/disc anterior
- z joint posterior
140
The collection of nerves at the end of the spinal cord are called the ______ _________ and reside in an enlarged subarachnoid space known as the lumbar _________.
- cauda equina
| - cystern
141
The cervical enlargment is from C_ to T_.
C5 to T1 (brachial plexus)
142
The lumbar enlargment is from L_ to S_.
L1 to S2 (lumbosacral plexus)
143
The connection of the spinal cord to the vertebral column and skull is made up of what 2 parts?
- denticulate ligaments
| - filum terminal
144
What is the function of the denticulate ligaments?
extensions of the pia mater that anchor the spinal cord to the dura mater
145
What are the 2 parts of the filum terminal?
- pial portion= filum terminal internum
| - dural portion= filum terminal externum
146
Trunk extension ________ stretch of the spinal cord while trunk flexion _______ stretch of the cord.
- reduces
| - increases
147
During trunk flexion, unfolding of axon within endoneurium results in __% increase length, while the elastic deformation results in the other __% of length.
- 70%
| - 30%
148
Trunk rotation ______ nerve roots and spinal nerves. The nerve roots are protected by what?
-stretches
- extra space in intervertebral foramen
- epidural fat in intervertebral space
- covering of dura mater
149
What are the 2 grooves in the spinal cord cross section?
- anterior median fissure
| - posterior median sulcus
150
The gray matter is the H shaped central core containing ______ and _______ cell bodies, and __________ neuron processes
- neuron
- neuroglia
- unmyelinated
151
The dorsal horn is composed of __________ involved in ________ signaling.
- interneurons
| - sensory
152
The ventral horn is composed of ___________ neurons and interneurons.
somatomotor
153
The ventral horn is ____________ organized. The medial ventral horn controls ______ muscles, the lateral ventral horn controls __________ muscles, the posterior section of the ventral horn controls ________, and the anterior section of the ventral horn controls ________.
- somatotopically
- axial
- appendicular
- flexors
- extensors
154
The lateral horn is only located in T_ to L_ and S_ to S_.
- T1 to L2
| - S2 to S4
155
Lateral horn T1-L2 is __________.Lateral horn S2-S4 is ____________.
- sympathetic
| - parasympathetic
156
What is Rexed's Laminae?
| Laminae 2 is the ________________ for noxious stimuli.
- 10 functional regions of gray matter in the dorsal and ventral horns
- substantia gelatinosa
157
What is the gray commissure?
connection between R and L gray matter that allow for signals to cross to the opposite side
158
White matter contains _________ and _________ tracts which are bundles of myelinated axons with similar origin and terminal destination
ascending and descending
159
The white matter is composed of a dorsal, lateral, and anterior ________
column
160
Propriospinal tracts function to do what?
they are axons that begin and end within the cord providing interconnections between tracts and gray matter for context
161
The central canal is continuous with the _______ of the brain and contains ______.
- 4th ventricle
| - CSF
162
What is the function of the spinal cord?
Nerve impulse propogation in ascending and descending tracts
163
What are the primary arteries feeding the spinal cord?
- anterior spinal a. to deep anterior cord regions
- 2 posterior spinal a. to deep posterior cord regions
- anterior and posterior radicular to superficial spinal cord segments
164
What are the veins draining blood from the spinal cord region?
- anterior median spinal v.
- anterolateral spinal v.
- posteromedian spinal v.
- posterolateral spinal v.
