Cranium, Scalp, Meninges, and Brain (part 2) Flashcards
1
Q
Outline for Lecture:
A
- Brain development
- Major lobar arrangement of cerebrum
- Primary functional regions and association areas
- Tracts, nuclei and their functions
- Organization and function of diencephalon and brain stem
2
Q
What is housed in the gray matter of brain tissue?
A
- Motor neurons
- Interneuron:
> cell bodies
> dendrites
> axon terminals
> unmyelinated axons
3
Q
What is white matter composed primarily of?
A
Myelinated axons.
4
Q
Druing brain development, an outer, superficial region of gray matter form from what?
A
Migrating peripheral neurons.
5
Q
External sheets of gray matter, called the cortex, cover the surface of what?
A
Most of the adult brain (the cerebrum and cerebellum).
6
Q
What are the three initial brain vesicles?
A
- prosencephalon - “forebrain”
- mesencephalon - “midbrain”
- rhombencephalon - “hindbrain”
7
Q
By what week in development have the three initial brain vesicles differentiated by?
A
end of the 4th week
8
Q
List the five secondary brain vesicles.
A
- telencephalon - from prosencephalon, forms the cerebrum.
- diencephalon - from prosencephalon, forms the thalamus, hypothalamus, and epithalamus
- mesencephalon - remains as in week 4
- metencephalon - from the rhombencephalon, forms the pons and cerebellum
- mylecephalon - from the rhombencephalon, forms the medulla oblongata
9
Q
When are the components of the secondary brain vesicles differentiated by during development?
A
5th week
10
Q
What does the telencephalon form?
A
cerebrum
11
Q
What does the diencephalon form?
A
thalamus, hypothalamus, and epithalamus
12
Q
What does the mesencephalon form?
A
mesencephalon
13
Q
What does the metecephalon form?
A
pons and cerebellum
14
Q
What does the mylencephalon form?
A
medulla oblongata
15
Q
What are the 4 major regions of the brain?
A
- cerebrum
- diencephalon
- brainstem
- cerebellum
16
Q
What is the cerebrum divided into?
A
Two halves - left and right cerebral hemispheres.
17
Q
what is each hemisphere subdivided into?
A
five functional areas called lobes
18
Q
What does the outer surface of an adult brain exhibit?
A
Folds called gyri (gyrus) and shallow depressions between those folds called sulci (sulcus).
19
Q
How many pairs of cranial nerves is the brain associated with?
A
12
20
Q
What makes up the brainstem?
A
- midbrain
- pons
- medulla (oblongata)
21
Q
What is the primary function of the frontal lobe?
A
> higher intellectual functions (concentration, decision making, planning):
- personality
- verbal communication
- voluntary motor control of skeletal muscles
22
Q
What is the primary function of the parietal lobe?
A
> Sensory interpretation of textures and shapes.
> Understanding speech and formulating words to express throughts and emotions (Wernicke’s area).
23
Q
What is the primary function of the temporal lobe?
A
> Interpretation of auditory and olfactory sensations.
> Storage of auditory and olfactory experiences.
24
Q
What is the primary function of the occipital lobe?
A
> Conscious perception of visual stimuli.
Integration of eye-focusing movements.
Correlation of visual images with previous visual experiences.
25
What is the primary function of the insula?
> Interpretation of taste.
| > Memory
26
Where is the premotor cortex located and what does it do?
> frontal lobe
| > coordinates learned skilled motor activities (e.g. playing the piano)
27
Where is the somatosensory association area located and what does it do?
> parietal lobe
| > integrates and interprets sensations to determine the texture, temperature, pressure, and shape of objects
28
True or False:
Primary motor and sensory cortical regions are connected to adjacent association areas that process and interpret incoming data or coordinate a motor response.
True
29
Where is the auditory association area located and what does it do?
> temporal lobe
| > interpret characteristics of sound and stores memories of sounds heard in the past ("ear worm")
30
Where is the visual association area located and what does it do?
> occipital lobe
| > process visual info by analyzing color, movement, and form to identify things we see
31
What are the two functional brain regions that have multiassociation areas?
> Wernicke's area
| > Gnostic area
32
Where is the Wernicke's area located and what does it do?
> left hemisphere
> recognize, understand, and comprehend spoken or written language.
- works with Broca's area which is the motor speech area
33
Where is the gnostic area located and what does it do?
> parietal, occipital, and temporal lobes
| > E.g., clock indicates 12:30, smell food cooking, friend talks about hunger, you interpret it to be lunch time.
34
What do association tracts connect?
Different regions of cerebral cortex within the same hemisphere.
35
What do commissural tracts do?
Connect the left and right cerebral hemispheres.
36
What do projection tracts link?
Cerebral cortex to the caudal brain regions (e.g., corticospinal tract from cerebrum to brainstem and spinal cord).
37
Are tracts in the brain white or gray matter?
central white matter
38
What do arcuate fibers connect?
Connect neighboring gyri within a single cerebral lobe.
39
What do longitudinal fasciculi connect?
Connect corresponding lobes of right and left hemispheres.
40
What are cerebral nuclei?
Paired irregular masses of gray matter buried deep within the central white matter.
41
What does the caudate nucleus do?
C-shaped-neurons within stimulate appropriate muscles to coordinate arm and leg movements associated with walking.
42
What is it and what does the amygdaloid body do?
>Expanded region at the tail of the caudate nucleus.
| > Participates in the expression and control of moods and emotions.
43
What nucleus does both the putamen and globus pallidus form?
Lentiform nucleus
44
What does the putamen control?
Muscular movement at a subconscious level.
45
What does the globus pallidus do?
Inhibits activity of the thalamus.
46
What does the claustrum do?
Subconscious processing of visual information.
47
What does the diencephalon provide the relay and switching centers for?
Some sensory and motor pathways and for control of visceral activities.
48
What gland is made up of the posterior portion of the epithalamus?
pineal gland
49
What does the pineal gland secrete?
melatonin
50
What does the epithalamus do?
Habenular nuclei help relay signals from the limbic system and control visceral and emotional responses to odors.
51
What is the only sensory impulse that is not received by the thalamus?
Sensory impulses from all conscious senses except olfaction converge on the thalamus.
52
What does the anterior structural group of the thalamus function to do?
mood
53
What does the medial structural group of the thalamus function to do?
consciousness and emotion
54
What does the lateral structural group of the thalamus function to do?
mood
55
What does the posterior structural group of the thalamus function to do?
special and somatic sense
56
What does the ventral structural group of the thalamus function to do?
somatomotor and somatosensory
57
What nuclei make up he hypothalamus?
- anterior nucleus
- dorsomedial nucleus
- mammillary body
- paraventricular nucleus
- preoptic area
- suprachiasmatic nucleus
- supraoptic nucleus
58
What structural group/nuclei make up the thalamus?
- anterior group
- lateral group
- medial group
- posterior group
- ventral group
59
What function is the paraventricular nucleus of the hypothalamus involved in?
produces of oxytocin
60
What function is the preoptic area of the hypothalamus involved in?
body temperature
61
What function is the anterior nucleus of the hypothalamus involved in?
parasympathetics
62
What function is the supraoptic nucleus of the hypothalamus involved in?
produces of ADH
63
What function is the suprachiasmatic nucleus of the hypothalamus involved in?
circadian rhythm
64
What function is the dorsomedial nucleus of the hypothalamus involved in?
sympathetic
65
What function is the mammillary body of the hypothalamus involved in?
olfaction and swallowing
66
What are the different structures of the mesencephalon?
- cerebral peduncle
- substaantia nigra
- tegmentum
- tectum
67
What tracts pass through the cerebral peduncle?
Motor tracts, coritcospinal tracts run through (pyramidal system).
68
What signals does the substantia nigra send?
inhibitory signals to skeletal muscles
69
What does the tegmentum do?
Sends involuntary motor commands to the erector spinae to maintain posture.
70
What is the tectum?
(corpora quadrigemina) relay station for visual and auditory sensations, visual reflex centers (superior colliculi), auditory reflex centers (inferior colliculi).
71
Is the auditory reflex centers located in the inferior or superior colliculi?
inferior colliculi
72
What reflex center is located in superior colliculi?
visual reflex center
73
What does the pons house and what does it do?
> Regulate rate and depth of breathing.
| > Houses nuclei for CN V, VI, VII and VIII.
74
What does the medulla do, house, and which tracts pass through it?
> corticospinal tracts and sensory relay (the olive).
> Nuclei for CN VIII, IX, X, XI, XII.
> Also, cardiac, vasomotor, respiratory, and those related to coughing, gagging, sneezing, salivation, swallowing, and vomiting.
75
Which nucleus in the medulla is related with proprioception?
olivary nucleus
76
What does the cerebellum do?
> Coordinates and fine tunes skeletal muscle movements and ensured that skeletal muscle contraction follows the correct pattern leading to smooth coordinated movements.
> Performs indirectly with voluntary and involuntary motor pathways.
77
What is the limbic system and what does it form a ring around?
```
> Ring around the diencephalon.
> Composed of various structures that collectively process and experience emotions.
- parahippocampal gyrus
- hippocampus (storing memories and longterm memory)
- amygdoloid body
- olfactory bulb
- fornix
- various nuclei in the diencephalon
```
78
What are the components of the limbic system?
```
> parahippocampal gyrus
> hippocampus (storing memories and longterm memories)
> amygdoloid body
> olfactory bulb
> olfactory tract
> fornix
> mammillary body
> septal nucleus
> anterior thalamic nucleus
> cingulate gyrus
> various nuclei in the diencephalon
```
79
List the motor spinal tracts.
> Posterior funiculus - medial lemniscal pathway
- fasciculus gracilis
- fasciculus cuneatus
> spinocerebellar pathway
- posterior spinocerebellar tract
- anterior spinocerebellar tract
> anterolateral pathway
- lateral spinothalamic tract
- anterior spinothalamic tract
80
List the sensory spinal tracts.
```
> lateral corticospinal tract
> rubrospinal tract
> anterior corticospinal tract
> reticulospinal tract
> vestibulospinal tract
> tectospinal tract
```
81
What does motor pathways use?
> upper motor neurons
| > lower motor neurons
82
What does sensory pathways use?
> primary neurons
> secondary neurons
> sometimes tertiary neurons
83
What does the posterior funiculus-medial lemniscal pathway do?
Conduct sensory impulses for proprioceptive information about limb position and discriminative touch, precise pressure, and vibration sensation.
84
What does the anterior spinothalamic pathway do?
Conducts sensory impulses for crude touch and pressure.
85
What does the lateral spinothalamic pathway do?
Conducts sensory impulses for pain and temperature.
86
What does the anterior spinocerebellar pathway do?
Conducts proprioceptive impulses from inferior regions of trunk and lower limbs.
87
What does the posterior spinocerebellar pathway do?
Conducts proprioceptive impulses from lower limbs, regions of trunk, and upper limbs.
88
What is the lateral coricospinal tract involved with?
Voluntary movement of limb muscles.
89
What is the rubrospinal tract involved with?
Discrete movement: flexors of limbs.
90
What is the anterior corticospinal tract involved with?
Voluntary movement of axial muscles.
91
What is the reticulospinal tract involved with?
posture
92
What is the vestibulospinal tract involved with?
Balance during movement.
93
What is the tectospinal tract involved with?
Visual and auditory integration with movement.
