Anatomy Practical 2 Flashcards
1
Q
what is the function of air sinuses
A
increases resonance of the voice
2
Q
what is the function of basal ganglia
A
Execution of voluntary motor control, routine behaviours
3
Q
what is the function of blood sinuses
A
venous drainage
4
Q
what is the function of cerebellum
A
Motor control (balance & coordination) & language
5
Q
what is the function of cingulate cortex
A
memory storage
6
Q
what is the function of hippocampus
A
memory formation
7
Q
what is the function of hypothalamus
A
Controls body temperature, hunger, thirst, circadian cycles & link between nervous and endocrine system
8
Q
what is the function of internal capsule
A
White matter containing ascending & descending axons
9
Q
what is the function of medulla oblangata
A
Involuntary functions (breathing, heart rate, blood pressure)
10
Q
what is the function of pituitary gland
A
endocrine gland
11
Q
what is the function of pons
A
Controls respiration and contains nuclei for CNV-VIII (control of their function)
12
Q
what is the function of thalamus
A
Relay station for sensory & motor info to cortex (conscious perception)
13
Q
What s the limbic system
A
- the limbic system is a group of structures that are located on the medial aspect of each cerberal hemisphere and diencephalon
14
Q
what is the limbic system
A
- it is the emotional or affective feelings in the brain
15
Q
what two parts of the limbic system are important in emotions
A
- amygdale
- anterior part of the cingulated gyrus
16
Q
What does the amygdale do
A
The amygdale recognizes angry and fearful facial expressions, assesses anger and elicits the fear response
17
Q
What does the cingulated gyrus do
A
The cingulated gyrus plays a role in expressing our emotions through gestures and in resolving mental conflicts when we are frustrated.
18
Q
what often triggers emotional reactions and memories and why
A
odors
- this reflects the origin of much of the limbic system in the primitive parts of the brain
-
19
Q
what is most limbic system output relayed through
A
- most limbic system output is relayed through the hypothalamus
- the hypothalamus is important
20
Q
what often triggers emotional reactions and memories and why
A
odors
- this reflects the origin of much of the limbic system in the primitive parts of the brain
- the olfactory bulbs are part of the limbic system and there are often connections with the olfactory bulb and the amygdale
21
Q
when acute emotional distress causes visceral illness this is called
A
actue stress disorder
22
Q
what allows a link between our feelings and thoughts
A
- The interactions with the prefrontal cortex allow an intimate relationship between our feelings and our thoughts.
- Therefore, we react emotionally to things that we consciously understand to be happening.
23
Q
why can we stop expressing emotions in inappropriate situations and why emotions can override logic
A
- due to the extensive links between the cortex and limbic system
24
Q
what system are the olfactory bulbs apart of
A
the limbic system
25
what limbic structures play a role in memory
- hippocampus
| - amygdale
26
describe the role the amygdale play in memory
The amygdale appears to label a stimulus with emotional meaning, it gives an ‘affective’ component.
27
describe the role the hippocampus plays in memory
ACh stimulation of the hippocampus is necessary for memory fomrtion
28
what does transsection of the fornix cause
Transsection of the fornix causes the loss of registration of new memories.
29
where does the reticular formation extend through
- it extend through the central cord of the medulla oblongata, pons and midbrain
30
describe the structure of the reticular formation
- composed of loosely clusters of neurones that form three broad columns along the length of the brainstem
31
what is the outstanding feature of reticular neurones
The outstanding feature of reticular neurons is their far flung axonal connections, making them ideal for governing the arousal of the brain.
32
how to the reticular neurones keep the cortex alert
certain reticular neurons, unless inhibited by other brain areas, send a continuous stream of impulses (via thalamic relays) to the cortex, which keeps the cortex alert and conscious and enhances its excitability
33
how much sensory stimuli does the reticular formation disregard
This system probably disregards about 99% of all sensory stimuli. If this would not occur, the sensory overload would drive us crazy.
34
what is the reticular formation system inhibited by
- sleep centres
- depression by alcohol
- sleep inducing drugs
- tranquilizers
35
what does severe injury to the reticular formation result in
Severe injury to this system results in permanent unconsciousness.
36
what do some reticular motor nuclei do
- project to motor neurones in the spinal cords - control skeletal muscles during coarse limb movement
- vasomotor, cardiac, and respiratory centres of the medulla oblongata are autonomic centres that regulate visceral motor functions
37
What is unconsciousness
Unconsciousness is a state which occurs when the ability to maintain an awareness of self and environment is lost
38
What is a coma
A coma is a prolonged state of unconsciousness.
39
What are the causes of coma
- hypoglycaemia
- injury to the head
- stroke
- infection to the brain
- alcohol poisoning
40
what is the difference between anterograde and retrograde amnesia
Retrograde amnesia is the inability to recall past memories (fornix) while anterograde amnesia is the inability to create new memories (hippocampus)
41
What is the basal ganglia
- this is a subcortical structure
42
What forms the basal ganglia
t the caudate nucleus, putamen and globus pallidus
43
what are the basal nuclei functionally associated with
The basal nuclei are functionally associated with the subthalamic nuclei of the diencephalon and the substantia nigra of the midbrain
44
What are the putamen and the globus pallidus collectively called?
lentiform nucleus
45
What are the putamen and the caudate nucleus collectively called?
corpus striatum
46
what does the basal nuclei do
- motor control complex
| - regulate attention and cognition
47
where do the striatum receive input from
- the entire cerebral cortex
| - other subcortical areas
48
what does the basal ganglia exert
The basal ganglia exert an inhibitory influence on a number of motor systems.
49
which nucleus of the basal ganglia is the major inhibitory input to the thalamus
Substantia nigra
50
what happens when dopamine is released from the substanita nigra
- When dopamine is released from the substantia nigra, there is a release of this inhibition that permits a motor system to become active.
- The "behaviour switching" that takes place within the basal ganglia is influenced by signals from many parts of the brain, including the prefrontal cortex, which plays a key role in executive functions.
51
what are the basal nuclei important in
- starting, stopping, and monitoring the intensity of movements executed by the cortex escpeically those that are slow or sterotyped
- inhibit antagonist or uncessary movements
52
what do disorders of the basal ganglia result in
Disorders of the basal ganglia result in either too little or too much movement as exemplified by Parkinson’s disease and Huntington’s chorea, respectively.
53
what arteries supply the basal ganglia
anterior choroidal
middle cerebral
anterior cerebral
54
How much of the cerebellum accounts of total brain mass
The cerebellum accounts for about 11% of total brain mass.
55
what does the cerebellum do
- provides the precise timing and appropriate patterns of skeletal muscle contractions for smooth, coorindated movement and agility
56
what does the cerebellum do
- provides the precise timing and appropriate patterns of skeletal muscle contractions for smooth, coorindated movement and agility
- predicts sequences of complex movements of the limb
- non motor functions include word association and puzzle solving
57
are we conscious or unconscious in cerebellar activity
cerebellar activity occurs without our awareness of its functioning
58
describe the structure of the cerebellum
- bilaterally symmetrical
- connected by vermis
- deep fissures divide each hemisphere into anterior, posterior and flocculonodular lobe
- flocculonodular lobe is deep to the vermis and cannot be seen in a surface view
- has an outer cortex of grey matter and an inner white matter
- have nuclei the most familiar is the dentate nuclei
- the white matter resembles a branching tree and is called arbour vitae
59
name the peduncles in the cerebellum
- superior cerebellar
- middle cerebellar
- inferior cerebellar
60
describe the superior cerebellar peduncles
The superior cerebellar peduncles connect the cerebellum to the midbrain and carry outputs from the cerebellum to the cerebral cortex via relay in the thalamus (there are no direct connections to the cortex).
61
describe the middle cerebellar peduncles
The middle cerebellar peduncles carry input to the cerebellum from the pons, advising the cerebellum of voluntary motor activities initiated by the cortex (relayed in the pons).
62
describe the inferior cerebellar peduncles
The inferior cerebellar peduncle carry input to the cerebellum from the medulla oblongata conveying sensory information to the cerebellum from muscle proprioceptors of the body and sensory information concerned with equilibrium and balance from the inner ear via brain stem relays
63
what is the functional scheme of cerebellar processing for motor activity
- The motor areas of the cortex notify the cerebellum of their intent to initiate voluntary muscle contraction. - At the same time, the cerebellum receives information from proprioceptors throughout the body. This information enables the cerebellum to evaluate body position and momentum.
- The cerebellum calculates the best way to coordinate the force, direction and extend of muscle contraction to prevent overshoot, maintain posture and ensure smooth, coordinated movement.
- Then via the superior peduncles (output), the cerebellum dispatches to the cerebral motor cortex its ‘blueprint’ for coordinating movement. The cerebellum also sends fibres to neurons in the brain stem that influence motor neurons in the spinal cord.
64
why are the cerebellar tonsils anatomically important
because there can be tonsillar herination in raised intracranial pressure
65
what structures does the diencephalon consist of
the thalamus, hypothalamus and the epithalamus (pineal gland)
66
out of the thalamus, hypothalamus, epithalamus (pineal gland)
Which of these structures is found anterior to the third ventricle?
Which of these structures is found posterior to the third ventricle?
Which of these structures forms the lateral walls of the third ventricle?
Which of these structures is found anterior to the third ventricle?
- epithalamus (pineal gland)
Which of these structures is found posterior to the third ventricle?
- hypothalamus
Which of these structures forms the lateral walls of the third ventricle?
- thalamus
67
where is the two thalamus connected
These masses are connected at the midline by the interthalamic adhesion.
68
what does the thalamus contain
- it contains a large number of nuclei msot named according to their relative location
- each has a functional modality and projects to or receives fibres from the cerebral cortex
69
what coverges in the thalamus
Afferents from all senses and all parts of the body converge in the thalamus and synapse with at least one of its nuclei.
70
what happens within the thalamus
- information is sorted and editied therefore the thalamus plays a key role in mediating sensation, motor activites, cortical arousal, learning and memory
71
what is the thalamus the gateway to
It is the gateway to the cerebral cortex (to consciousness).
72
What information do these nuclei receive
- Lateral geniculate nucleus (LGN)
- Medial geniculate nucleus
- Ventral posterior lateral nucleus
- Anterior nucleus
- Ventral lateral nucleus
- Ventral anterior nucleus
- vision
- hearing
- touch, pain, pressure
- - memory
- motor input from cerebellum
- Motor input from basal ganglia
73
where is the hypothalamus located
- it is located below the thalamus
| - contains several important nuclei
74
what is the epithalamus and what does it do
The epithalamus consists of the pineal gland, which secretes melatonin, which together with the hypothalamus regulates the sleep and wake cycle.
75
what does the CSF do
Cerebrospinal fluid (CSF) is found in and around the brain and spinal cord, forms a liquid cushion and gives buoyancy to the brain
76
how much does the CSF reduce brain weight by
By floating the brain, the CSF effectively reduces brain weight by about 97% and prevents the brain from crushing under its own weight (1.3 kg
77
what is the CSF similar to
- CSF is similar in composition to blood plasma, from which it is formed, but it contains fewer proteins and its ion concentrations are different.
- In adults, the total CSF volume of about 150ml is replaced every 8h, hence about 500ml of CSF are formed daily
78
what is the CSF formed by
choroid plexuses
79
what happens if CSF is obstructed
- CSF is produced and drained in a constant rate.
- If something such as a tumour, however, obstructs its circulation or drainage, it accumulates and exerts pressure on the brain.
80
what is it called when the CSF is blocked in babies
hydrocephalus
- causes the head to enlarge - this is because the skull bones are not fused
- but in adults brain damage occurs more rapidly becasue the skull is rigid and hard and sometimes accumulating fluid compresses blood vessels serving the brain and crushes the soft nervous tissue
81
what is it called when the CSF is blocked in babies
hydrocephalus
- causes the head to enlarge - this is because the skull bones are not fused
- but in adults brain damage occurs more rapidly because the skull is rigid and hard and sometimes accumulating fluid compresses blood vessels serving the brain and crushes the soft nervous tissue
82
what structure connects the lateral and third ventricle
The lateral ventricle is connected with the third ventricle via the foramen of monro.
83
What structure connects the third and fourth ventricle?
The third ventricle is connected to the fourth ventricle via the cerebral aqueduct
84
The fourth ventricle is found anterior to what structure?
cerebellum
85
What structure forms the lateral walls of the third ventricle?
thalamus
86
What separates the two anterior horns of the lateral ventricles?
septum pellucidum
87
The inferior horn of the lateral ventricle is found in which lobe?
temporal lobe
88
What structure is found at the tip of (anterior to) the inferior horn of the lateral ventricle?
putamen?
89
What structure penetrates the third ventricle connecting both sides of the lateral walls
interventricular foramina ??
