Revision cards Flashcards
What produces myelin in the CNS?
Oligodendrocytes
What produces myelin in the PNS?
Schwann cells
What makes up the PNS?
31 pairs of spinal nerves and 12 pairs of cranial nerves.
What type of neurones make up the majority of the nervous system?
Multipolar neurones
Describe dendrites in relation to the cell body?
Dendrites carry info towards the cell body.
Describe axons in relation to the cell body?
Axons carry information away from the cell body.
What is the difference between oligodendrocytes and Schwann cells?
Oligodendrocytes can wrap multiple axons in myelin whereas schwann cells can only wrap one.
Function of microglia
Immune monitoring and antigen presentation in the CNS
Function of ependymal cells
Line the ventricles- ciliated columnar/cuboidal epithelium.
What type of astrocytes are found largely in white matter?
Fibrous astrocyte.
What is a fissure?
A fold that is deeper than a sulcus.
Which type of matter is on the outside of the brain?
Grey matter
What does grey matter contain?
Neurones, cell processes, synapses and support cells
What does white matter contain?
Myelinated fibres.
Where does the frontal lobe lie?
Anterior to central sulcus
Superior to lateral sulcus
Where does the parietal lobe lie?
Posterior to the central sulcus
Superior to the lateral sulcus
Anterior to the parietal-occipital sulcus
Where does the occipital lobe lie?
Posterior to the parietal occipital sulcus.
Where does the temporal lobe lie?
Inferior to the lateral sulcus.
What is the 5th lobe called? Where is it hidden?
Insular lobe- 5th lobe
Hidden in the lateral fissure.
What are the three layers of the meninges called?
Dura mater
Arachnoid mater
Pia mater.
What plexus’s does the enteric nervous system have? Where are they located?
Has a myenteric plexus (between outer layers of smooth muscle) and submucosal plexus (in the submucosa)
What drains into the internal jugular vein?
Dural venous sinuses.
What are dural venous sinuses?
Where the blood from the brain drains to.
What is a collection of cell bodies in the PNS called?
Ganglia
What is a collection of cell bodies in the CNS called?
Nucleus
What is a multipolar neurone?
2 or more dendrites. It has its cell body in the CNS.
What is a unipolar neurone?
Double process. Has cell body in PNS.
What is a nerve?
What is the name for this in the CNS?
A collection of axons surrounded by connective tissue and blood vessels.
A tract.
Where are spinal nerves found?
ONLY found in intervertebral foramina.
What does each spinal nerve supply a body segment with?
General sensory
Somatic motor to skeletal muscles
Sympathetic nerve supply to the skin and smooth muscle of arterioles.
What is a dermatome?
An area of skin supplied with sensory innervation from one spinal nerve.
What is a myotome?
The skeletal muscles supplied by a single spinal nerve.
On a dermatomal map, where is the male nipple?
T4.
On a dermatomal map, where is the umbilicus?
T10.
Where do sympathetics flow out of the spina cord from?
T1-L2.
Which nerves contain parasympathetics?
10,9,7 and 3.
What are the four options for parasympathetic nerves to travel via (not the nerves themselves e.g. CN X)?
Via ciliary ganglion- to the eye
Parasympathetic ganglia in the head- lacrimal gland and salivary gland.
Via vagus nerve- to the abdominal organs as far as the midgut, neck and chest.
Sacral spinal nerves- hindgut and perineum.
What anchors the spinal cord in the canal?
What is it made from?
The denticulate ligament.
Made from arachnoid and Pia mater anchoring it to the dura at various points.
What is the end of the spinal cord termed?
Conus medullaris
What is the continuation of the spinal cord to the dorsum of the coccyx called?
Filum terminale.
Describe the distribution of matter in the spinal cord?
Grey matter- inside
White matter- outside.
What does the central canal open into in the head?
The 4th ventricle.
What is the arterial supply to the spinal cord?
Longitudinal arteries- 2 posterior and one anterior. Originating from vertebral arteries.
Radicular arteries- travel along dorsal and ventral roots.
Segmental arteries- from intercostal, vertebral and lumbar arteries.
What is the venous drainage of the spinal cord?
By longitudinal and segmental veins.
Where exactly is the epidural space?
In between the dura mater and periosteum in the spinal canal. This space doesn’t exist in the cranial cavity because the dura is adhesive to the periosteum.
Where is the primary somatosensory cortex?
Postcentral gyrus (parietal lobe).
Where does the cerebellum sit?
In the posterior cranial fossa, subtentorium (below the tentorium cerebelli).
Describe the matter distribution of the cerebellum?
White matter core with grey matter outside.
How does the cerebellum attach to the brainstem?
Via three stalks called peduncles.
Middle, inferior and superior cerebellar peduncles.
What is the middle region of the cerebellum called?
The vermis.
What are the three layers of the cerebellum- from superficial to deep?
Molecular cell layer
Purkinje cell layer
Granule cell layer.
Where in the cerebellum does proprioceptive information arrive and from here where is it transmitted?
Arrives in the granular cell layer which is then communicated to the purkinje cell layer (which then sends info to the deep cerebellar nuclei) and the molecular cell layer.
Where will the afferents that arrive in the cerebellum come from?
Spinal cord- containing somatic proprioreceptors and pressure receptors
Cerebral cortex - brain needs to tell the cerebellum what its doing.
Vestibular apparatus- tells about balance
How do afferents enter the cerebellum?
Via the cerebellar peduncles and project mainly into the granular cell layer.
How is information output from the cerebellum?
Only output is via the purkinje cells which mainly communicate with the deep cerebellar nuclie.
Axons exiting the cerebellum will synapse where?
They synapse in the medulla after decussation.
Cerebellar lesions influence the ipsilateral or contralateral side of the body?
Ipsilateral (on the same side)
If there is a unilateral hemispheric lesion in the cerebellum, what signs might show?
Disturbance of co-ordination in limbs.
Intention tremor
Unsteady gait