N2. external features of brian Flashcards
Cranial
‘towards the head’
Caudal
‘tail end’
Rostral
‘towards the face’
Peripheral nervous system (PNS)
- all nervous tissue outside the CNS, mainly nerves:
- cranial nerves
- spinal nerves
- autonomic nerves
3 anatomical parts of brian
- Cerebrum
- Cerebellum
- Brainstem
what is the cerebral cortex
The surface of the cerebrum
folds of cortex are called
gyri
grooves of cortex are called
sulci
types of sulci
- Central
- Lateral
- Parieto-occipital
types of gyri
- Precentral gyrus
- Postcentral gyrus
frontal lobe function
- motor area
- pre-central gyrus = primary motor cortex
parietal lobe function
- sensory area
- postcentral gyrus = primary somatosensory cortex
occipital lobe function
- visual area
- primary visual cortex
temporal lobe
auditory area
what is broca’s aphasia
damage to broca’s area in prefrontal cortex causes an issue with speech production = language deficit
cerebellum functions
- coordination of movement
- maintaining balance and posture
- motor learning
strucure of cerebellum
- found in posterior cranial fossa
- separated by tentorium cerebelli
- highly folded cortex-folia
- arbor vitae = tree of life = white matter
external features of cerebellum
superior
- anterior lobe
- primary fissure
- posterior lobe
- vermis
inferior
- peduncles
- HZ fissure
- flocculonodular lobe
- flocculus
- tonsils
- nodule
what are cerebellar peduncles
- fibre bundles attached to the brainstem
- Carry input and output to and from the cerebellum
- Superior peduncle-midbrain
- Middle peduncle-pons
- Inferior peduncle-medulla
morphological divisions of cerebellum
- vermis
- lateral hemispheres
- flocculonodular lobe
LVFL
functional divisions of cerebellum
Spinocerebellum (S):
- Sensing proprioceptive input
- Adapting the body to changing circumstances (i.e., posture regulation)
Cerebrocerebellum (C):
- Regulating the cerebral cortical motor
- Output (i.e., fine coordination of limb movement)
- Inhibiting involuntary movement
Vestibulocerebellum (V):
- Maintaining balance, spatial orientation and muscle tone
- Integrating vestibular information for controlling eye and head movements
what are cranial meninges
- The brain and spinal cord are covered with membranes called meninges
- suspended in cerebrospinal fluid
layers of meninges
- dura mater
- arachnoid mater
- pia mater
- = PAD
dura mater structural features
- tough
- layers:
- periosteal
- meningeal
- can form sinuses
- infoldings of dura
- falx ceribri
- falx cerebelli
- tentorium cerebelli
- diaphragma sellae
arachnoid and pia mater
- Arachnoid mater: deep to the dura.
- Thin and loosely encloses the brain and spinal cord.
- Pia mater: deep to the arachnoid.
- Adhered to the surface of the brain and spinal cord.
- Very thin and cannot be seen with the naked eye
what are ventricles filled with
CSF
functions of CSF
- Protects the brain by providing cushion against trauma
- Provided nutrients to the brain
- Prevents nerves and blood vessels from being compressed between the brain and skull
where is CSF produced and circulated
choroid plexus
- circulates through ventricles
- subarachnoid space
- reabsorbed by arachnoid villi into venous circulation
describe the ventricular system of the brain
2X Lateral ventricles
Interventricular foramen (Foramen of Munro)
Third ventricle
Cerebral aqueduct (Sylvian aqueduct)
Fourth ventricle
Central canal
types of haemorrhages
Extradural - between the skull and dura mater
Subdural - between dura and arachnoid mater (appears as a crescent on a CT)
Subarachnoid - between the arachnoid and pia
Intracerebral - rupture of small vessels leading to bleeding in the brain tissue
types of haemorrhages
Extradural - between the skull and dura mater
Subdural - between dura and arachnoid mater (appears as a crescent on a CT)
Subarachnoid - between the arachnoid and pia
Intracerebral - rupture of small vessels leading to bleeding in the brain tissue
hydrocephalus
build up of CSF within the ventricles, resulting in enlarged ventricles
what might cause extradural haemorrhages
result of a tear of the meningeal arteries
what might cause subdural haemorrhages
typically after high impact injury
what might cause subarachnoid haemorrhages
- typically after head injury
- blood surrounds the brain and fills the sulci
what might cause intracerebral haemorrhages
what might cause subarachnoid haemorrhages
what might cause intracerebral haemorrhages
what might cause subarachnoid haemorrhages
