Anatomy 12 and 13 - Nervous System Flashcards
What are the 2 anatomical divisions of the nervous system?
CNS (brain, spinal cord)
PNS (all tissues not within the spinal cord)
What type of nerves do you get within the PNS? (3)
Spinal nerves (connect with the spinal cord) Cranial nerves (connect with the brain) Autonomic nerves (control organs, smooth muscles, glands, can be visceral afferents, sympathetic nerves or parasympathetic nerves)
What type of autonomic nerves do you get? (3)
Visceral afferents
Sympathetic nerves
Parasympathetic nerves
Parts of a neurone? (4) + function
Dendrites (receive and conduct info towards cell body)
Body (processes information)
Myelin sheath (insulates nerve fibre helping signal travel quicker)
Axon (or nerve fibre - conduct signal away from cell body)
What is a collection of nerve cell bodies called in the:CNS?PNS?
CNS= nucleus PNS= ganglion
What are bundles of axons called in the:CNS?PNS?
CNS = tract PNS = nerve
What are nerves?
Bundles of axons (nerve fibres) wrapped in connective tissue which are travelling to or from the same region
What can bundles of axons leave a nerve as?
Branches
What is a synapse?What happens at the synapse?
The region where one neurone communicates with another neurone in a ganglion in the PNS or in a nucleus in the CNS An electrical signal (AP) becomes a chemical signal (neurotransmitter) then an electrical signal again
What are the 3 main parts of the brain?
The cerebrum
The cerebellum
Brain stem
What are the 4 main lobes of the cerebrum?
Frontal
Temporal
Parietal
Occipital
What is the outer layer of the cerebrum called?
Cerebral neocortex (cortex)
What are the 2 halves of the cerebrum called?
Right and left cerebral hemisphere
What does the cerebral neocortex consist of on its surface and what are these?
Gyrus (pl. gyri) = ridges
Sulcus (sulci) = dips
What are the 2 layers of cerebrum in the brain and what does each section contain?
Grey matter (cerebral cortex) = outermost layer full of cell bodies) White matter = deep to grey matter, contains many myelinated axons giving the white appearance
What is the order of matter in the spinal cord?
white matter is superficial
Grey matter is deep
Name of the 12 cranial nerves?
I = olfactory nerve II = optic nerve III = oculomotor nerve IV = trochlear nerve V = trigeminal nerve VI = abducent nerve VII = facial nerve VIII = vestibulocochlear nerve IX = glossopharyngeal nerve X = vagus nerve XI = spinal accessory nerve XII = hypoglossal nerve
From anterior to posterior, in which order do the cranial nerves attach to the brain?
CN I - XII
except CN XII is between CN IX and CN X
Name of the 3 fossae of the cranial cavity?
Anterior cranial fossa
Middle cranial fossa
Posterior cranial fossa
Which cranial nerve passes through the cribriform plate of the ethmoid bone?
CN I
What CN passes through the optic canal?
CN II
What cranial nerves pass through the superior orbital fissure?
CN III, IV, V1 (ophthalmic nerve) and VI
What cranial nerve passes through foramen rotundum?
CN V2 (maxillary nerve)
What nerve passes through foramen ovale?
CN V3 (mandibular nerve)
What CNs pass through the internal acoustic meatus?
CN VII and VIII
What nerves pass through jugular foramen?
CN IX, X and XI
What nerve passes through the hypoglossal canal?
CN XII
Look at position of foraminae on diagram
…
What foraminae does the spinal cord pass through?
The foramen magnum
What are the 3 parts of the course of a CN?
CNS partIntracranial part
Extracranial part
What protects the spinal cord?
The vertebral canal
What are the 4 segments of the vertebral canal?
Cervical
Thoracic
Lumbar
Sacral/ coccygeal
what are the enlargements of the spinal cord?What causes these?
Cervical
Lumbosacral
The limbs
What connects bilaterally to the spinal cord?
Spinal nerves
At what intervertebral disc level does the spinal cord end?
L1/L2
What is the tapered lower end of the spinal cord called which usually occurs around L1/L2 IV disc level?
Conus medullaris
What is a nerve root?
The base of a nerve as it branches off the spine or brain
why is the vertebral column longer than the spinal cord?
Lumbar and sacral spinal nerves have to descend in the vertebral canal to their respective intervertebral foraminae
How many pairs of spinal nerves are there?
31
How many pairs of each of the types of spinal nerves are there and what are their names?
8 cervical spinal nerves (C1 - C8) 12 thoracic spinal nerves (T1-T12) 5 lumbar spinal nerves (L1-L5 )5 sacral spinal nerves (S1-S5) 1 coccygeal spinal nerve (Co)
How many vertebrae are there?
33
How many of each type of vertebrae are there?
7 cervical 12 thoracic 5 lumbar 5 sacral (fused to form 1 sacrum) 4 coccygeal (fused to form 1 coccyx)
How are spinal nerves named?
According to the vertebrae above them except in the cervical region, where they are named according to the vertebrae below it
Where does C8 spinal nerve exit
C7 and T1
What spinal nerves supply?
The soma (body wall) (as well as other things)