Nervous system Flashcards
describe the division of the nervous system
there is the CNS and the PNS
- CNS divides into the brain and spinal cord
- PNS divides into the somatic and autonomic nervous system
- autonomic system divides into the sympathetic nervous system and the parasympathetic system
what is the central nervous system responsible for
- The central nervous system is responsible for integrating processing and coordinating sensory data,
what is the somatic nervous system
- The somatic nervous system is the voluntary nervous system which controls skeletal muscles
what is the autonomic nervous system
- The autonomic nervous system is the non-voluntary nervous system it controls - glands - blood vessels - internal organs
what is the sympathetic nervous system
this mobilises body for action and has energy output, this is the fight or flight response
what is the parasympathetic system
this conserves energy and maintains a quiet state, this is the relaxing part of the nervous system
what is the nervous system made up of
made up of neurones which have different sizes and functions but they all have the same basic body plan
what does the change in size and shape depend on
- Change in size and shape depends on how many dendrites (sensory processes) that they have
what do dendrites do
picks up the sensory information from the relay or the peripheral and taking it to the cell body and sending an electrical information down the axon either to another neurone or skeletal muscle
what do small neurones act as
the small neurones act as a relay between other neurones
what is the ratio of neurone to glia
1 neurone to 9 glia
what do glia do
- Glia cells are cells that package cells in the nervous system (glue and hold neurones in place and support neurones and protect neurones)
what do the oligodendrocytes do
are myelinating, send out myelin that wrap around axons, found in the CNS
what do the astrocytes do
regulate extracellular fluid and environment around the neurones and protecting the neurones, form a blood brain barrier and help protect and regulate what gets in from the blood supply into the rest of the brain
what do the microglia do
protect brain from infection, usually don’t do much and are silent and switched off because the astrocytes is forming the barrier, if something breaks through the barrier then they become active and phagocytose the dead tissue and protect the brain from the infection and damage spreading
what does the ependymal do
line fluid filled cavities in the brain and important for regulating the fluid and moving the CFS fluid around the brain and spinal cord. CFS full of nutrients and keeps the buoyancy of the brain light
what are the specialised cells in the PNS
- The axons are myelinated by schwann cells, wrap around axon insulating it and protecting it therefore keepting the electrical activity inside the cell
- Satellite cells are the alternative to astrocytes which are found around the cell body in the PNS which support the cell body
- General macrophages and the rest of the immune cells protect the nervous cell as there is no blood brain barrier
what type of blood supply does the brain have
dual blood supply
what part of the brain do the internal carotid arteries supply
- there are left and right internal carotid arteries that supply the front part of the brain and the anterior circulation
what part of the brain do the 2 vertebral arteries supply
come up the back of the vertebra, they fuse into the single artery called the basilar artery this goes up the brain stem and divides (back into 2) into the posterior cerebral arteries this does 1/3 of blood supply, back of the brain such as the cerebellum and brain stem
what interconnects the arteries in the brain
- Interconnected such as the posterior and anterior communicator arteries.
what is the vein in the brain called
cerebral veins
describe the job of the cerebral vein
- collecting the Venus drainage
- once oxygenated blood has been round the brain and has picked up carbon dioxide and other waste products this is removed by this cerebral vein. The cerebral vein is reliant on gravity to bring the blood flow back from the brain, the blood goes into the sinus and then through the jugular foramen where the internal jugular vein starts.
what are the sinuses
folds in the dura
what are the three layers of the dura
Dura marta
arachnoid marta
pia marta
describe the arachnoid Marta
this is the spiders layer looks like a spider layer that has been thrown over surface of the brain,
describe the Pia Martra
layer we cant see)– stuck on surface of the brain and goes into the indentations that we have in the brain.
where is the CFS found
found between the Pia and arachnoid