Soft Tissue Structure And Function

Question 1

Classify the epithelial tissue

Answer 1

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

Question 2

Functions of epithelial tissue

Answer 2

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

Question 3

Explain the glands in the endocrine system

Answer 3

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

Question 4

Explain glands in the exocrine system

Answer 4

Secrete products into ducts that empty on to the epithelial surface
Examples - digestive, enzymes, sweat and tears

Question 5

Explain connective tissue

Answer 5

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

Question 6

Classify the connective tissue

Answer 6

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

Question 7

Classify the connective tissue

Answer 7

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

Question 8

Functions of connective tissue

Answer 8

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

Question 9

Explain cartilage

Answer 9

Closely packed collagen fibres embedded in a firm matrix gel containing chondrocytes and proteoglycans 
Avascular 
Types of cartilage 
- hyaline cartilage 
- elastic cartilage 
- fibrocartilage

Question 10

Explain hyaline cartilage

Answer 10

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

Question 11

Explain elastic cartilage

Answer 11

Numerous elastic fibres 
Resilient but flexible 
Found: 
- external flap (auricle) of ear 
- epiglottis 
- auditory tube 
- small cartilages in larynx

Question 12

Explain fibrocartilage

Answer 12

Densely interwoven collagen fibres 
Little ground substance 
Durable and tough 
Resists compression and absorbs shock 
Found:
- between vertebrae 
- between pubic bones 
- meniscus

Question 13

Explain membranes and their 4 types

Answer 13

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

Question 14

Explain mucous membrane

Answer 14

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)

Question 15

Explain serous membranes

Answer 15

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

Question 16

What are the 3 types of serous membranes

Answer 16

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

Question 17

Explain synovial membranes

Answer 17

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

Question 18

Explain cutaneous membrane (skin)

Answer 18

Two layers: 
- epidermis (epithelial tissue)
- dermis (connective tissue)
Subcutaneous layer of loose connective tissue 
Accessory structures

Question 19

What’s the function of cutaneous membranes

Answer 19

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

Question 20

What are the general facts

Answer 20

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