Nervous system Flashcards
L8 L9 L10 L11
What is the function of the nervous system?
It is the master controlling and communication centre of the body.
It co-ordinates and controls all essential functions of the body.
It provides information on the environment and allows the body to respect accordingly.
It is capable of higher functions such as memory, learning and emotions
What is the structure of a standard neuron?
It had all the essential membrane-bound organelles such as rER, sER, mitochondria, ribosomes, nucleus, golgi apparatus etc.
Additionally, there are specialised organelles: Dendritic spine, dendrite, axon hillock and axon.
Why is there myelination on neurons?
Myelination is when Schwann cells or oligodendrocytes wrap around the axons. It speeds up conduction rates of neurons.
What is the endoneurium?
They’re delicate connective tissue layer surrounding axons and are associated Schwann cells.
https://i.pinimg.com/originals/07/7f/f9/077ff929651054cc8103a91a35579eff.jpg
What is the perineurium?
It is a connective tissue layer surrounding groups of axons forming fascicles.
https://i.pinimg.com/originals/07/7f/f9/077ff929651054cc8103a91a35579eff.jpg
What is the epineurium?
A connective tissue layer that surrounds fasicles and blood vessls. This forms the nerve.
https://i.pinimg.com/originals/07/7f/f9/077ff929651054cc8103a91a35579eff.jpg
What is saltatory conduction?
Propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction speed of action potentials.
What is Nissl staining used for?
What is chromatolysis?
Nissl staining is a staining method used on nervous tissue sections.
Chromatolysis is loss of Nissl solutions
What types of neurons are there?
Functional classification
Afferent (sensory), efferent (motor), interneurons (relay)
Structural classifications
Multipolar, bipolar , unipolar
What are Purkinje cells?
.
What are Neuroglia?
What types of neuroglia are there?
Otherwise known as just glia. Their function is to support neurons.
Astrocytes, Oligodendrocytes, Microglia, Ependymal cells and Schwann cells (maybe)
What are astrocytes and their function?
Star shaped glial cells, which are the most abundant glia in the brain.
They regulate water levels, K+ levels and neurotransmitter levels.
They inhibit axon regeneration.
What are oligodendrocytes function?
Myelinating glia in the CNS. One oligodendrocyte can myelinate multiple axons
They also inhibit axon regeneration.
What are microglia function?
They are specialised macrophages, found only in the CNS. They respond to inflammation, microorganism, foreign substances, the standard macrophages things
What are ependymal cells function?
They line brain ventricles and spinal cord central canal. Specialised ependymal cells form choroid plexuses (which is within the brain ventricles). Choroid plexuses secrete CSF.
What are the Schwann cells function?
Myelinating glia in PNS. One schwann cell wraps around a part of the axon.
They promote axon regeneration.
How is the nervous system organised?
The tree diagram
https://o.quizlet.com/sF45bsyirINf04Dg6QzI4w.jpg
What separated a CNS neuron from a PNS neuron?
CNS neuron is entirely contained within the spinal cord or brain.
PNS neuron is entirely outside of the brain or spinal cord or if any parts of the neuron protrudes form the spinal cord.
For humans, what is the: Dorsal axis Anterior axis Posterior axis Ventral axis
Dorsal = backside Anterior = upward Posterior = downward Ventral = belly-side
What is the sagittal plane?
What is the coronal plane?
What is the horizontal plane?
Sagittal = Through the nose to back of head Coronal = Ear to ear (vertical) Horizontal = Self-explanatory
What is the hindbrain?
The pons, cerebellum and medulla form the hindbrain.
They support vital bodily processes.
Where does the spinal cord end?
L1/L2
https://s3.amazonaws.com/reeve-assets-production/BrainSpinalCordlabld.jpg
What is the spinal cord’s spinal nerves comprised of?
8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal
Where is the white matter and grey matter in the nervous system?
White matter is on the inside of the brain and the outside of the spinal cord.
Grey matter is on the outside of the brain and on the inside of the spinal cord.
What are fissures, sulci and gyri?
What is the purpose of them?
Ridges of the brain are known as gyri.
Grooves are known as sulci.
Deeper grooves are known as fissures.
They increase the surface area of the cerebral cortex so allows more neural material to be contained within the skull
What are the lobes of the brain?
Where are they located?
The frontal lobe is at the front of the brain
Occupital lobe is at the back of the brain
Parietal is at the mid-top region of the brain
Temporal lobe is below the parietal
What is the cerebrospinal fluid and what is its function?
CSF is made by specialised ependymal cells and is fluid found within the central canal and the skull surrounding the brain. CSF is reabsorbed into the venous system.
Function is to provide buoyancy of the brain and protect the brain (the fluid absorbs shock so allows brain to not sustain that much damage). Additionally the CSF removes waste products.
What is hyrdocephalus?
When the cerebrospinal fluid isn’t absorbed back into venous system causing swelling of the head.
What are the 3 meninges?
Pia mater (inner) Arachnoid mater (middle) Dura mater (outer)
What is the Pia mater?
The innermost meningeal layer which is fine and delicate.
It allows entry of blood vessels to the brain and provides an impermeable layer containing the CSF.
What is the Arachnoid mater?
Middle meningeal layer which is silky and web-like (hence arachnoid).
It protects CNS together with the other meninges.
What is the Dura mater?
The outermost meningeal layer which is tough.
It protects the CNS together with the other meninges. Forms sinuses that carry venous blood.
How is the CSF flushed out from the brain?
CSF leaves through the sub-arachnoid space intos superior sagittal sinus.
