Nervous System 1 Flashcards
discuss the organisation/components of human brain
1.telencephalon (cortex and deep structures of cerebrum)
2.diencephalon (thalmus and hypothalmus)
3.mesencephalon midbrain pon sand medulla oblongata, all 3 collectively known as brainstem
4cerebellum
list the key principles of the brain
-the most sophisticated functions (conscious awareness, decisions making, reasoning) are located at top and front of our brains
-older more primitive systems were not removed through evolutionary history and neither were they significantly updated, or altered in any way
-localisation of function is straight forward for older systems, but not so for higher order systems liek long term memory or personality
the name of the fluid that the brain swims in
cerebrospinal fluid
what is the brain (CNS) protected by
skull, meninges and CSF
describe CSF
a solution that provides an enviroment that insulates the brain
-protects the brain
the role of the blood brain barrier
ensures that only essential mollecules (glucose/oxygen) pass into brain
describe the coronal section
-Subcortical nuclei, stained sections within the white matter
-Grey matter. The stain is attracted to cell bodies of neurons
-White matter. This is myelin and not picked up by the stain
-Ascending and descending tracts. Axons entering or leaving the cerebrum
-Hollow space in centre of brain called a ventricle. These are fluid filled
what are neurons responsible for
ALMOST EVERYTHING
-excitation
-inhibition
-modulation
list all the systems of the brain
-CNS
-PNS
-ANS
-SNS
discuss the autonomic nervous system
split up into
-sympathetic and parasympathetic
controll basic physiological functions;visceral activities such as thermoregulation,digestion,circulation
work to maintain homeostatsis
-Sympathetic and parasympathetic target same tissues; opposite effects.
-Both systems are constantly active.
discuss the nerve connection of autonomic pathways
preganglionic-sympathetic reside in spinal cord (thoracic and lumbar); parasympathetic originate
in brain and lower spinal cord. Both secrete acetylcholine.
Postganglionic: sympathetic secrete norepinephrine and are adrenergic fibers;
parasympathetic secrete acetylcholine and are cholinergic fibers.
discuss the blood supply to the brain
supplied by 2 pairs of arteries
internal cartoid arteries (ICA)
-anterior 2/3 brain
veterbral arteries
-posterior 1/3 of brain
branches from both form an important anastomosis on base of brain=circle of willis
discuss the circle of willis
-anterior, middle and posterior cereberal arteries
-anterior and posterior communicating arteries complete circle
Sits on inferior surface of the brain (in subarachnoid space)
Allows blood that enters brain via ICA or vertebral arteries to be distributed to any part of both hemispheres
Important collateral blood supply
Variation in size of arteries is common, absence of one or both posterior communicating arteries has been reported
describe cerebrovascular accident (CVA)
an interuption of blood flow to brain causing cell death-stroke
5-8seconds-unconcsciousness
4-6minutes-irreversible brain damage can occur
list the risk factors of CVA /stroke
-sex,age,ethnicity,prior stroke/TIA, family history
-hypertension, heart disease, high cholesterol, diabetes, atrial fibrillation, smoking and obesity
list the tyoes of strokes and describe them
ischemic-(85%)-blockage of a vessel supplying brain
haemorrhagic(15%)- when blood vessels supplying brain leaks or ruptures (bleed surface brain)
what are the effects of a stroke
can result in
-inability to move one or more limbs on one side of body
-inability to understand or formulate speech
-inability to see one side of visual field
