Soft Tissue Structure And Function Flashcards
(20 cards)
Classify the epithelial tissue
Includes epithelia and glands
Epithelia are cells that cover internal or external surfaces
Glands produce fluid secretions and are either attached to or derived from epithelia
Cells are bound closely together and are continuously replaced/regenerating
Has an exposed surface
Epithelia are avascular
Functions of epithelial tissue
Physical protection - protect exposed/internal surfaces from abrasion, dehydration and destruction by chemical/biological agents
Control permeability - any substance entering or leaving the body must cross an epithelium, variable permeability and absorption, secretion, excretion and diffusion
Provide sensation - large sensory nerve supply, continually providing info about internal/external environment, smell, taste sight,equilibrium and hearing
Produce specialised secretions - secretions produced by glands, secretions are either discharged onto the surface of the epithelia or released into interstitial fluid/blood
Explain the glands in the endocrine system
Ductless glands
Secrete hormones into cellular spaces, them into blood
Hormones regulate or co-ordinate activities of various tissues, organs and systems
Examples - pituitary, thyroid and thymus glands
Explain glands in the exocrine system
Secrete products into ducts that empty on to the epithelial surface
Examples - digestive, enzymes, sweat and tears
Explain connective tissue
Occur throughout the body
Never exposed to the outside environment
Connect the epithelial tissue to the rest of the body
Many are highly vascular
Fill internal spaces
Classify the connective tissue
Loose connective tissue is made up of loosely packed collagen and elastin fibres and is found throughout the body. It fills the spaces around organs. The elastic fibres within the tissue make it resilient, so it easily returns to its original shape after external pressure is removed
Adipose tissue - much higher proportion of fat cells, it provides padding, absorbs shocks and insulates the body and stores energy
Blood and lymph are fluid connective tissues that transport cells and dissolved materials
Classify the connective tissue
Cartilage is found in joints on articular surfaces and it protects the bone, it can help shock absorption and reduces friction between bone surfaces. It is composed of densely packed collagen fibres to withstand compression
Bone provides support, allows movement - attachment point for skeletal muscles and protects organs. Formed from densely packed collagen with mineral deposits, primarily calcium
Functions of connective tissue
Establishing structural framework for the body Transports fluids and dissolved materials Protects delicate organs Supports, surrounds and connects other types of tissues Stores energy (triglycerides) Helps to defend body from invading micro-organisms
Explain cartilage
Closely packed collagen fibres embedded in a firm matrix gel containing chondrocytes and proteoglycans Avascular Types of cartilage - hyaline cartilage - elastic cartilage - fibrocartilage
Explain hyaline cartilage
Most common type Closely packed collagen fibres in matrix Tough but flexible Found: - in most joints covering articular surfaces - between ribs and sternum - nasal cartilage - respiratory tract
Explain elastic cartilage
Numerous elastic fibres Resilient but flexible Found: - external flap (auricle) of ear - epiglottis - auditory tube - small cartilages in larynx
Explain fibrocartilage
Densely interwoven collagen fibres Little ground substance Durable and tough Resists compression and absorbs shock Found: - between vertebrae - between pubic bones - meniscus
Explain membranes and their 4 types
Membranes occur when epithelial tissue and connective tissue is combined
Consists of epithelium supported by connective tissue
4 types:
Mucous membranes
Serous membranes
Cutaneous membranes
Synovial membranes
Explain mucous membrane
Line passageways that open to exterior including digestive, respiratory, urinary and reproductive tracts
Epithelial surfaces are kept moist to reduce friction and facilitate absorption/secretion
Thin layer of epithelial cells (often simple classification)
Explain serous membranes
Line the sealed, internal subdivisions of the body cavities
Not open to the exterior
Very thin and transparent
Firmly attached to body wall and organs that they cover
Minimise friction - serous fluid produced
What are the 3 types of serous membranes
Peritoneum - lines peritoneal cavity and covers surface of exposed organs
Pleura - lines the pleural cavity and covers the lungs
Pericardium - lines pericardial cavity and covers heart
Explain synovial membranes
Membrane around the joint cavity of a synovial joint, forms a synovial capsule
Made up of connective tissue with a layer of macrophages and fibroblasts
Synovial fluid within capsule - lubricates and nourishes the hyaline cartilage
Movement of the joint stimulates formation and circulation of synovial fluid
Explain cutaneous membrane (skin)
Two layers: - epidermis (epithelial tissue) - dermis (connective tissue) Subcutaneous layer of loose connective tissue Accessory structures
What’s the function of cutaneous membranes
Protection of underlying tissue Excretion of salts, water and waste products Maintenance of temperature Production of melanin/keratin Synthesis of vitamin D3 Storage of lipids Sensation Co-ordination of immune response to pathogens/cancers in the skin
What are the general facts
Takes 15-30 days for a cell to move to the outermost layer of the skin (stratum corneum)
Cells last for approx 2 weeks
Holds water
Colour can indicate changing or pathological conditions
