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13 Cards in this Set
- Front
- Back
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Types of neurone
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Multipolar with 2+ processes, consitute majority of neurones
Pseudo-unipolar with bifurcating process, found in dorsal root ganglia Bipolar with 2 processes (1 axon and 1 dendrite), found in cochlear, vestibular ganglia, olfactory mucosa and retina |
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Description of sensory ganglia
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Cranial nerve ganglia (e.g geniculate, trigeminal ganglia) and dorsal root ganglia are examples
Cell bodies have relatively large soma with many satellite cells to each one |
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Description of sympathetic ganglia
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Cell bodies multipolar and generally smaller than in sensory ganglia
Fewer satellite cells per cell body as a result Do feature synapses |
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Description of parasympathetic ganglia
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Akin to sympathetic ganglia with relatively smaller multipolar cells
Main distinction is location very close to target tissue Postganglionic cells have relatively short fibres |
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Description of myelinated and unmyelinated axons in the PNS
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Myelinated fibres show distinctive envelopment by concentric myelin lamellae of Schwann cell, one glial cell to one fibre
Unmyelinated fibres enveloped en masse by Schwann cell, do not have concentric lamellae, surrounded instead by glial cytoplasm |
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Components of the extracellular matrix
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Collagen fibres, resist strength, most abundant protein in body
Elastic fibres, able to stretch and recoil, elastin (glycoprotein) and embedded proteinaceous microfibrils are most important components Ground substance, amorphous gel holding the previous two components |
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Types of collagen
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Main types are I-IV
Type I collagen is most common, around 90%, large fibres and bundles, striated fibrils Type II collagen, fine fibres in ECM Type III collagen, skin and round blood vessels Type IV collagen, meshwork of fine fibres, epithelial basement membrane |
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Types of connective tissue
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Varying compositions of the extracellular matrix produce different types of connective tissue:
Loose connective tissue Dense connective tissue Elastic connective tissue Cartilage and bone Fat Blood |
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Loose connective tissue properties
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10-20% collagen fibres
Fairly fluid ground substance Space for white blood cell populations Potential space for cell growth and differentiation Found deep to gut epithelium |
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Dense connective tissue properties
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Higher density of collagen, can rise to 90% in tendons and ligaments
Role in resisting expansion or pulling Fascia, epineurium, tendon, ligaments and capsules around the liver and kidney all constitue dense connective tissue |
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Elastic connective tissue properties
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High density of elastic fibres
Elastic content decreases with age Found in skin, urinary bladder, walls of arteries, alveolar septa |
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Properties of ground substance
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Secreted by fibroblasts mainly
GAGs, proteoglycans (core proteins with GAGs), glycoproteins (smaller than proteogylcans) Glycoproteins include laminin (adhesion of basement membrane to epithelium) and fibronectin (cell adhesion) Ground substance has role in cell development, healing and repair, and diffusion |
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Cells secreting the ECM and composition of ECM in different tissues
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Fibroblasts secrete ECM (ground substance) in most tissues
Chondroblasts in lacunae in cartilage, matrix contains proteoglycans and much collagen Osteoblasts in bone (ECM has hydroxyapatite, calcium salt) Myofibroblasts in muscle (also contractile) |
