Human Brain And Its Relations Flashcards
What is function of myelin
Increase speed and reliability of impulse conduction
What is responsible for myelinating glial cells in CNS
Oligodendrocytes
What is the function of the largest division (Cerebrum)
Cerebral cortex - sensation and perception, voluntary functions, cognitive functions
Basal ganglia - movement planning and control
Diencephalon:
Thalamus - different nuclei
Hypothalamus - responsible for regulating appetites when to eat etc.. Endocrine functions to pituitary gland
Epithalamus- secretes melatonin (helps regulate sleep and shut physiology)
What is brain made of in specific Grey matter
Site of information processing where the cell bodies and dendrites of neurons synaptically receive terminal axons
White matter?
Axons of neurons and associated myelin sheaths oligodendrocytes
Cell membranes of oligodendrocytes wrapped around CNS axons - Lipid fat..
Information transfer due to the long pathway
Corpus callosum and internal capsule
Axons between neuron bodies of right and left cortical hemispheres
Internal capsule - carries white matter connection between cerebral cortex and subcortical structures
What is the gyrus and sulci
Gyrus are the thick ridges of the brain whereas sulci are the furrows in between the gyrus
What are the four main lobes
Frontal lobes - control voluntary movements
Parietal lobe - somatic sensation touch/thermal pain etc.. conscious
Occipital lobe - vision
Temporal lobe - hearing and audition
Difference between CT and MRI
CT - cheaper and multiple X rays are fired on different parts of the brain to give a represented
Each x ray beam shows separate single image of brain which computer assembles
MRI - much more in depth analysis expensive whereby ox lies in scanner and magnetic force around head - computerised system puts together different slices of head into one image
Adv - white and grey matters easily distinguished diagnosis of MS much more viable
What are the 3 meninges of the brain
Dura
Arachnoid
Pia
What is the dura matter
Tough fibrous outer layer collagenous material
Suspend brain within skull to prevent brain movement when skull is moved
Arachnoid layer
Spidery middle layer
Cling film around brain
Contains high S.A of cerebrospinal fluid and blood vessels
Pia layer
Innermost layer of the brain
Contributes to blood brain barrier
What is the Subdural haemorrhage
Caused by head injury internal bleeding and rupture of blood vessels that force from dura to arachnoid of meninges
What are the two sets of arteries that supply the brain with blood
Internal carotid - supply anterior brain via ophthalmic, middle and anterior cerebral
Vertebrals - supply posterior brain; after they get into the skull via foremen magnum
Rupture of posterior cerebral artery
Issue with occipital lobe so whole right hand side of visual field is tampered with
Rupture of left middle cerebral artery
Bits of frontal, parietal and temporal lobe tampered with, so losses with voluntary movements, conscious, somatic sensation etc..
What is the purpose of anterior communicating artery in C.O.W
function is to connect bloodstream from right anterior cerebral and the left hemisphere, in case there is a blockage in either one of the two - provides an alternate pathway
Describe the CSF movement and circulation
Produced in lateral ventricles, then flows into third ventricle through interventricular foramina. It then moves from third to fourth via cerebral aqueduct
After in fourth ventricle, it escapes through foramen of magendie and foramen of luschka
Define hydrocephalus
Water on the brain, when the skull bones haven’t yet hardened, the CSF accumulates causing head to expand especially in foetus
