Tissues Flashcards
Name the 4 tissue types & their subcategories
Excitable - muscle & nervous
Non-excitable - connective & epithelial
What is the main feature of muscle tissue?
Contractile - allows movement
Explain skeletal muscle?
Muscle fibres are long, thin & striated - attached to bones & tendons - fibres arranged in bundles - nerves give graded movement of muscle
Explain cardiac muscle?
Striated - heart - cells interconnected - intercallated discs couple cells electrically & mechanically - all fibres contract simultaneously
Explain smooth muscle?
Not striated - GI tract, urinary, & reproductive tract, blood vessels, bronchioles - contractile tubing - circularly arranged (lumen) - peristalsis
What is the main function of nervous tissue?
Transit impulse & sensory perceptions (neurons & neuroglia)
Explain about neuron structure & function?
Generate & conduct electrical impulse - dendrites receive impulse, cell body containing nucleus, axon conduct impulse to other neuron or effector, - unidirectional
Explain neuroglia?
5 per neuron - structural & functional support to neuron - can divide - oligodendrocytes (CNS) & Schwann cells (PNS) produce myelin sheaths
What is connective tissue?
Binds, supports, protects, stores fat, erythropoeisis, fills space - blood vessels, ECM (protein & fluid) - connects all tissue types
Explain the dermis?
Connective tissue - collagen matrix - cells such as blood vessels & nerve cells
Explain adipose tissue?
Adpiocytes - cells wrap around fat globule - globule size regulated by cytoplasmic enzyme
Explain bone?
Connective tissue - osteoblasts secrete calcite - trapped - osteocytes which receive nutrients from blood vessels passing through the central canal & canaliculi
What is an organ?
Structure composed of ≥2 tissue types
Explain the functions of epithelial tissue?
Protects, secretes, absorbs, excretes, body surfaces & glands
Explain some features of epithelial tissue?
No blood vessels, low ECM tightly packed cells, reproduce readily
Where is epithelial tissue found?
Skin, sweat glands, mouth, lips, lungs, gut, kidneys, & blood vessels
Explain some ways epithelial tissue can be distinguished from each other?
Stratified & simple epithelial - apical surface exposed to lumen, basolateral surface connects cell to basement membrane - cells held together by tight junction - keratinised & non-keratinised
Give an example of dual endocrine/exocrine glands and their products?
Pancreas - Endocrine=insulin & exocrine=digestive enzymes
Testes - Endocrine=testosterone & exocrine=sperm
Ovaries - Endocrine=oestrogen & exocrine=ova
What is an endocrine gland?
Secretes in body into bloodstream - renin & melatonin
What is an exocrine glands?
Secretes via ducts outside the body - sweat glands & salivary glands
