Histology practical 4 IMMS - blood and nerves Flashcards
(33 cards)
what is the lumen bounded by
layer of squamous epithelial cells on a basement membrane
what is outside of the epithelium
the intima (consists of the endothelium, connective tissue (collagen, laminin, fibronectin, and other extracellular matrix molecules), and a basal layer of elastic tissue called internal elastic lamina)
what is outside of the intima
the media - comprised of smooth muscle, fibroblasts, collagen and elastin, this is then bound by the external elastic lamina
what is outside of the media
the adventitia (connective tissue composed of collagen and elastin)
what are large arteries near the heart usually classified as
elastic arteries
what are arteries further from the heart classified as
muscular arteries - these have some elastin sheets in the media
how many muscle layers in an arteriole
3 or fewer (and less than 100um)
what are capillaries comprised of
only the vascular endothelium cells on the basement membrane as they dont have a media, adventitia, intima, external or internal elastic lamina
what are the cells that manage the size of the capillaries
pericytes
what is it called when the vascular endothelium in the capillaries isn’t complete
fenestrated - material can leave circulation - often found in kidneys and liver
what are veins and venules missing that arteries have
external elastic lamina, they also have a larger lumen and smaller media and valves
do venules have pericytes
yes they have a continual layer wrapped around them, as they get larger the pericytes are replaced with smooth muscle
how can the smooth muscle in the walls of veins be arranged
circumferentially or longitudinally
what do lymphatics contain and what are they comprised of
valves like veins, lymph (derived from blood plasma). they are comprised of collagen, elastic fibres and smooth muscle
are peripheral nerves myelinated
yes most are, this is done by the schwann cells which produce the myelin
what is present between individual axons
endoneurium
what binds axons together to form nerve fibres
perineurium
what binds nerve fibres together to form a peripheral nerve
epineurium
nerves and blood vessels are often found together, what is this called
neurovascular bundle
what is the CNS version of schwann cells
oligodendrocytes
what cells produce the myelin in the PNS
schwann cells
how many axons per schwann cell and how many schwann cells per axon
only one axon per schwann cell but the number of schwann cells per axon depends on its length
what is the difference between myelinated and non-myelinated axons
at any one point on a myelinated axon there is one schwann cell but on a non-myelinated axon there is more than one schwann cell associated with the axon at any one point
where are the cell bodies of motor neurones
in the grey matter of the spinal cord
