205 NS - Histology Flashcards
Nissel substances or bodies are seen with a light microscope. Which subcellular structure represents Nissl bodies?
Rough endoplasmic reticulum
Where in the nervous system, in relation to the propagation of an action potential, are the sodium and potassium channels concentrated?
Node of Ranvier
Oligodendrocytes vs Schwann cells
Oligodendrocytes - CNS - forms multiple sheaths (up to 30 or more) around different axons
Schwann cells - PNS - forms a single myelin sheath around an axon
Dyneins
Retrograde transport - walk towards the minus end of a microtubule
Kinesin
Anterograde transport - walk towards the plus end of a microtubule
What are the 2 types of stroke?
Ischemic - clot stops the blood supply to an area of the brain
Hemorrhagic - blood leaks into brain tissue
What are the 2 types of ischemic stroke?
Cerebral thrombosis
Cerebral embolism
Cytotoxic edema vs vasogenic edema
Cytotoxic - cell swelling caused by intracellular accumulation of fluid
Vasogenic - extracellular accumulation of fluid resulting from disruption of the blood-brain barrier (BBB) and extravasations of serum proteins
Risk factors of ischaemic stroke.
Age Male sex Hypertension Hypercholesterolemia Diabetes Obesity Poor diet Lack of physical activity Smoking Atrial fibrillation Obstructive sleep apnoea
Risk factors of hemorrhagic stroke.
Age Hypertension Cerebral amyloid angiopathy Cerebral aneurysm Anterio-venous malformation Brain tumor Antiplatelet & anticoagulants Low platelets or impaired clotting function Illicit drug use
Risk factor for BBB breakdown
Hypertension Developmental defect Hyperosmolarity in blood Microwaves & radiation Infection
Nissl bodies
rER of neuron; site of protein synthesis
Astrocytes
Type of glial cell, star-shaped
Function - neurogenesis & synaptogenesis
What maintains the BBB?
Astrocytes & endothelial cell
What are the 3 layers of connective tissue around a nerve? (outermost to innermost)
Epineurium
Perineurium
Endoneurium
