Brain and skull Flashcards
(49 cards)
1
Q
number of skull bones
A
- 28:
- 8 cranium
- 14 facial
- 6 ear
2
Q
external bones of face
A
- 2 zygomatic (cheek bones)
- 2 maxillary (each side of nose)
- 1 mandible (jaw)
- 2 nasal (base of nose)
3
Q
suture
A
- joints between cranial bones
- interdigitate so minimal movement
4
Q
8 bones of skull (7 external, 1 internal)
A
- frontal (1 at front)
- 2 parietal (1 on either side on top in middle)
- occipital (1 at back)
- 2 temporal (1 on either side at bottom of cranium)
- sphenoid (1 directly behind face spanning both sides)
- ethmoid bone (internal)
5
Q
3 sutures
A
- coronal suture - frontal and parietal
- lambdoidal suture - occipital and parietal
- squamous suture - temporal and parietal
6
Q
fontanelle
A
- gaps between sutures
- not joined at birth to allow growth
7
Q
3 meninges
A
1) dura mater 2) arachnoid 3) pia mater
8
Q
dura mater
A
- Outer-most layer of meninges
- Dense and fibrous – tough
- Two layers - Inner layer forms the dural reflections
- Space between the layers forms venous sinuses
9
Q
3 Dural reflections
A
- Falx cerebri - separates cerebral hemispheres - median plane
- Falx cerebelli - separates cerebellar hemispheres - median plane
- Tentorium cerebelli - separates the cerebrum from the cerebellum - horizontal plane
10
Q
venous sinus
A
- Form between outer and inner layers
- Venous drainage from the brain
11
Q
arachnoid
A
- Layer beneath the dura mater
- Contains blood vessels
- Does not extend into sulci (‘valleys’)
- sits of spidery legs creating sub-arachnoid space
12
Q
Subarachnoid space
A
- Between the arachnoid and the pia mater
- Filled with cerebrospinal fluid (CSF)
13
Q
Arachnoid granulations
A
- Perforate the dura
- Transport “old” CSF from subarachnoid space into venous sinus
14
Q
Pia mater
A
- Transparent and delicate
- Blood vessels in arachnoid sit on top of pia mater
- Adheres to brain and follows gyri and sulci
15
Q
meninges of spinal cord
A
cover spinal cord is same way as brain
16
Q
ventricular system
A
- Network of interconnected “spaces” within the brain
- Filled with cerebrospinal fluid (CSF), which nourishes and protects the brain
- CSF is produced by the choroid plexus, which lines the ventricles
17
Q
CSF
A
nourishes and protects brain
18
Q
choroid plexus
A
produces CSF
19
Q
ventricular system
A
20
Q
Circulation of the CerebroSpinal Fluid
A
- Circulates through ventricles and subarachnoid space of the brain and spinal cord
- Route:
- Lateral ventricle
- 3rd ventricle
- cerebral aqueduct
- 4th ventricle
- subarachnoid space
21
Q
hydrocephalus
A
- caused by abnormal accumulation of CSF in the ventricles of the brain
- Leads to increased intracranial pressure inside the skull,
- Progressive enlargement of the head,
- Other symptoms include convulsion, tunnel vision, mental disability.
22
Q
lobes, sulci and gyri of brain
A
23
Q
function of occipital lobe
A
vision
24
Q
function of parietal lobe
A
sensory
25
function of temporal lobe
memory and hearing
26
function of posterior front lobe
motor
27
function of anterior frontal lobe
pre-frontal cortex
28
29
function of pre-motor cortex
planning of movement
30
function of primary motor cortex (post-central gyrus)
execution of movement
31
function of pre-frontal cortex and effect of damage
* Decision making
* Anticipating consequences of our actions
* Emotion
* Damage can change “who we are”
* Development may be altered by alcohol
* Involved in mental illnesses that change who we are, e.g. schizophrenia
32
division of brain
33
brainstem anatomy ventral view
34
3 types of white matter in brain
1. commissural tracts
2. projections tracts
3. association tracts
35
36
commissural tracts
* Axons cross from side to side; go both ways.
* Example: Corpus callosum
37
projection tracts
* axons extend between cortex and other CNS areas
* e.g. corticospinal tract
38
association tracts
* axons on same side within cerebral cortex
* communication between brain areas
* Example: communication between motor cortex and premotor cortex
39
Primary motor cortex organisation
Specific regions of the motor cortex control specific regions of the body
40
corticospinal tract
* descending somatic motor tract
* Controls activity of somatic (efferent) motor neuron
* Cell bodies (EFFERENT) in primary motor cortex
* Most fibres cross to opposite side in medulla oblongata
* Axons descend until spinal cord
* Synapse in spinal cord (ventral horn)
41
Parietal lobe function
* Somatosensory
* Integration of multiple types of sensory information
* Association
42
Simple somatic sensory (afferent) pathway
43
Primary somatosensory cortex
• Specific regions of the somatosensory cortex receive sensory information
44
45
integration between motor and sensory systems - role of cerebellum
1. Motor cortex initiates movement
2. Copy of instructions sent to cerebellum
3. Some sensory information goes to the cerebellum = information about actual movement
4. Cerebellum compares this info with copy of motor output
5. “Adjusts” motor output for COORDINATION
* The cerebellum coordinates movement, guided by sensory feedback.
46
5 nuclei of basal ganglia
1. caudate
2. putamen
3. globus pallidus
4. subthalamic nucleus
5. substantia nigra
47
basal ganglia function
* In a brain circuit that also involves other structures
* Select an appropriate movement for a given situation
* Initiate movement
* Terminate movement
48
5 nuclei of Basal Ganglia
1. caudate
2. putamen
3. globus pallidus
4. subthalamic nucleus
5. substantia nigra
49
function of basal ganglia
* selects an appropriate movement for a given situation
* initiate movement
* terminate movement
