the brain Flashcards
what percentage of oxygen consumption does the brain need?
~20%
how long (without oxygen) before the brain suffers permanent damage?
4 minutes
other than oxygen what else does the brain need constantly?
glucose
what substance helps protect the brain?
the blood brain barrier
what does the blood-brain barrier allow into the brain?
O2
CO2
alcohol
anaesthetic agents
what does the blood-barrier do?
controls the entry of materials
what are the parts to the brain stem
medulla
oblongata
pons
midbrain
where is the medulla oblongata in the brain?
inferior/lower part of the brainstem
what is the medulla oblongata made up of?
white matter expending between spinal cord & other parts of the brain
where is the brain stem at?
continuous with spinal cord
does it contain nuclei/clusters of cell bodies
yes
how many vital reflex centres are there in the medulla?
3
what are the three vital reflex centres
cardiovascular centre (heart rate)
medullary rhythmicity area (respiratory rhythm)
vasomotor (vasoconstriction)
anything else? in the medulla
has other sensory & reflex motor areas
-sneezing, coughing & vomiting
where is the brain stem - pons located
above/superior to the medulla oblongata
how does Pons connect within the brain?
connects the spinal cord with the brain
links one part of the brain with another by way of tracts/groups of nerve-axons
which one of the brain stems have the nerve tract cross?
Pons
what is the nerve tract cross
nerves supplying left side of the body cross to right side of the brain and right side of the body to left side of brain
what does the midbrain do?
connects pons to the diencephalon
conveys motor impulses from cerebrum to the cerebellum and spinal cord
contains the substantia nigra
conveys sensory impulses from spinal cord to thalamus
what is the substantia nigra
areas affected by parkinson’s disease
-dopamine
where is the diencephalon located in the brain
above the brain stem
what is included in the diencephalon
thalamus
hypothalamus
pineal gland
what does the thalamus do?
critical relay for sensory input
transmits motor info from cerebellum & basal nuclei to cerebrum
how many different things can hypothalamus do?
6
what can hypothalamus do?
control of ANS-regulation of many activities
control of pituitary and hormone production
regulation of emotional & behavior patterns
regulation of eating & drinking
control of body temperature
regulation of circadian rhythms & states of consciousness
what does the pineal gland do?
secretes melatonin which promotes sleep
where is the cerebrum located?
the top and largest part
what is the surface covered in (cerebrum)
grey matter (cortex)
beneath is cerebral white matter
how many parts is there to the cerebrum
4
name the parts included in cerebrum
cerebral cortex
internal white matter
grooves
longitudinal fissure
what is the cerebral cortex do in the cerebrum?
the grey matter/cell bodies
what is the internal white matter in the cerebrum?
its the surface folds
gyri-gyrus (singular)
what are the grooves in the cerebrum called?
sulci-sulcus
what does the longitudinal fissure do in the cerebrum
divides it into left & right hemispheres
what does the verebrum connect to?
corpus callosum
if the brain receives an input from the left side where does it send its output?
to the right side of the body
what side of the brain is involved with spoken & written language, numerical & scientific skills
left side of cerebrum
what does the right side of the cerebrum deal with?
spatial and patter recognition and emotional content
where is the cerebellum located
back of brain stem
what is the meaning behind cerebellum?
little brain
how many cerebellar hemispheres are there
two
where are the two cerebellar hemispheres located
posterior to medulla and pons below cerebrum
what is the cerebellar cortex made from
grey matter
what is the interior made from
white matter
nuclei
what does it cerebellum attach to
attached to brain stem via cerebellar peduncles
what are cerebellums functions?
sensory input
co-ordinates skeletal muscle
functions noticeable after excessive alcohol intake
what does the cerebellum co-ordinate in skeletal muscle
maintenance of normal muscle tone
regulates posture and balance
when is the brain most likely to develop?
first few years of life
when does the brain start to decline in brain mass
from early adulthood onwards
