Neuroanatomy and cells of the CNS Flashcards
What are the ridges and impressions in the cerebral hemisphere called?
Sulci-impressions(lines) Gyri-ridges
What does the brain stem consist of in descending order?
Midbrain, Pons, Medulla
What is the function of the cerebellum?
Coordinates voluntary movements including posture balance and coordination and speech
What are the different types of neuron morphology and describe them?
UNIPOLAR-Consists of one extension from the cell body (single axonal projection)
PSEUDO-UNIOPOLAR- single axonal projection that divides into 2 segments (cell body can often be in the middle of the axon splitting it into 2 segments)
BIPOLAR- 2 projections from the cell body (axon and dendrite)
MULTIPOLAR- Neurones with multiple projections from the cell body (most common neurone)
Pyramidal cells- Neurones with a pyramidal shaped soma(cell body) and 2 distinct dendritic trees. BASAL dendrite emerge from the base and APICAL dendrites fro the apex of the pyramidal cell body
PURKINJE AND GOLGI CELLS- GABA neurones found in the cerebellum
What is the function dendrites?
unmyelinated receives signals from other neurons and transmits electrical signals to the soma then to the axon
What are astrocytes?
Most abundant cell type in the CNS Can proliferate
What distinct structures do astrocytes have?
Astrocyte end feet that extend from the soma
What are the 5 functions of astrocytes?
Maintenance of the Blood Brain Barrier - Through PARACRINE interactions with endothelial cells and pericytes. Astrocytes secrete classes of factors with BARRIER PROMOTING/BARRIER DISRUPTING effects.
Paracrine factors from astrocytes further help blood flow regulation
Cell repair- they synthesise NEUROTROPHIC Factors (soluble proteins that support growth, survival and differentiation of neurones).
Upon CN damage astrocyes occupy space to form a GLIAL SCAR. They proliferate and migrate to areas of damage
Homeostasis- Neurotransmitter removal and reuptake. They have PLASMA MEMBRANE TRANSPORTERS (e.g. glutamate transporters for neurotransmitters GABA and glutamamte)
Which cells are myelin producing cells?
Oligodendrocyte- Consists of numerous projections that form the internodes of myelin. One oligodendrocye myelinates multiple axons
Schwaan Cells- Wraps itself around axon repeatedly to form myelin sheath around one axon. Produces myelin for peripheral nerves
Describe microglial ?
specialised immunological cells with similar function as macrophages (clearing cell debris and impaired neurons via phagocytosis)
Descreibe ependymal cells?
- line FLUID FILLED VENTRICLES
- regulate the production and movement of the CEREBROSPINAL FLUID , within the the ventricular system of the brain.
- There surfaces are covered with CILLIA that assist in the movement of fluid through the CNS
