Soft Tissue Structure And Function Flashcards
4 types of body tissue
Connective tissue - fill internal spaces, structural support, transports materials and stores energy
Epithelial tissue- lines interval cavities and passageways and external surfaces and forms glands
Muscle tissue- specialised for all types
Nervous tissue- carries info through electrical impulses
What makes up epithelial tissue?
Epithelial cells and glands
What surfaces does epithelial tissue cover?
Skin Lines the digestive tract Respiratory tract Urinary tract Reproductive tract
Delicate epithelia line internal cavities Chest cavity Fluid filled spaces in the brain Inner surfaces if blood vessels Chambers of the heart
What do glands do?
Derived from epithelial cells or attached to them.
Produce fluid secretions
Are cells spread or bound tightly in epithelium?
Epithelial cells are bound closely
Describe blood supply and regeneration of epithelial tissue
Epithelial tissue is avascualr and receives nutrients thro diffusion or absorption,
Epithelial cells lost or damaged can regenerate and continuously replaced
4 functions of epithelial tissue
P C P P
Physical protection- any surface covered in epithelium protected from abrasion, destruction and dehydration by biological agents
Control permeability- epithelial control what enters and exits cells. Varying degrees of permeability
Permeability involves ASED; Absorption, secretion, excretion and diffusion
Provide sensation- Epithelium has large sensory nerve supply
Info about internal and external environment
Eg, smell, taste, equilibrium and hearing
Produce secretions- glands produce secretions onto surface, or into interstitial fluid
Features of each epithelial cell
Basal surface = cell attach to connective tissue or more epithelial cells
Mitochondria - produces ATP
Nucleus- controls cell and carries DNA
Microvilli- increase SA Of cell by X20, so faster absorption and secretion
Cilia- move substances over epithelium
Eg, cilia moves mucus from lungs and centrally to throat
How can we classify epithelial tissue?
Number of layers : Simple or stratified
Cell shape: squamous, cuboidal or columnar
Eg, Stratified epithelium at the surface of mouth or skin so plenty of layers if damage occurs + rapid regeneration
Eg, simple epithelium is found where more secretion and absorption are (eg, intestinal lining)
Describe endocrine glands
Ductless glands
Secrete hormones into extracellular fluid and then into blood
Hormones travel in blood to specific receptor and coordinate and regulate activity of that organ, tissue or system.
Eg, pituitary, thyroid and thymus gland
Describe exocrine
Secrete products through a duct onto a surface of into a cavity
Eg, digestive enzymes, sweat glands and tears
Skin has sebaceous gland to secrete waxy substance to lubricants hair on skin
Connective tissue
All over the body
Not exposed to outside environment
Connects epithelium to rest of the body
Many are highly vascular - but not all!
Fills internal spaces between cells
Supports tissues and organs
Stores energy
Transports materials round the body
Describe classification of connective tissue
CONNECTIVE TISSUE PROPER= Loose CT, dense CT and adipose
FLUID CONNECTIVE TISSUE- Blood and lymph
SUPPORTING CONNECTIVE TISSUE- Cartilage and bone
Loose connective tissue
Loose collagen and elastic fibres
Fills spaces around organs
Elastic fibres make it resilient - returns to normal shape
Adipose tissue
Has collagen fibres, elastic fibres and many fat cells
Provides padding
Absorbs shock
Insulation
Stores energy
Fat pads in synovial joints to reduce friction between bone and tendon
Dense CT
Also known as fibrous connective tissue
Can be dense regular = Parallel collagen fibres packed densely eg, tendons and ligaments
Dense irregular = Collagen fibres interweave to form a mesh, eg, dermis layer
Fluid connective tissue
Blood and lymph
Transports cells and dissolved minerals round body
Involved in inflammatory and immune responses
Cartilage
On articulate surfaces of joints Protects bone Shock absorption Reduce friction between bones Dense packed collagen fibres - withstand pressure
Bone
Support
Attachment for skeletal muscles
Flat bones protect internal organs
Has mineral deposits like calcium
6 functions of connective tissue
1) Gives structural framework to body - eg, bones and loose CT
2) Transports fluids and materials eg. Lymph and blood
3) protects delicate organs eg, loose CT and bone
4) support, surround and connect other tissues eg, loose CT
5) stores energy eg, adipose stores triglycerides
6) defend body from pathogens eg, in blood and lymph with immunity cells and CT proper has macrophages and lymphocytes
Describe cartilage in more detail
Cartilage is in a gel matrix with closely packed collagen fibres - can cope with stresses
CHONDROCYTES - Cartilage cells
Produce and maintain matrix
Secrete chemical to prevent blood vessels in cartilage tissue
Cartilage is avascualr - nutrients via matrix. Does not heal well.
PROTEOGLYCANS: Pritein and sugar
Regulate molecule movement through matrix
Affects how cartilage copes with stresses
WHAT ARE THE 3 types of cartilage ?
HYALINE CARTILAGE
ELASTIC
FIBROCARTILAGE
HYALINE CARTILAGE
Closely packed collagen fibres
Tough but flexible
Found in:
Most joints over surfaces eg, hip joint femoral, head and acetabulum. But acetabular labrum is fibrocartilage.
Between ribs and sternum
Nasal cartilage
Respiratory tract (around trachea etc)
ELASTIC
Resilient and flexible
High proportion of elastic fibres
Found in: External flap of ear Epiglottis (prevent food and liquid into the lungs ) Auditory tube Small caritilages in larynx
