Soft Tissue Structure And Function

Question 1

4 types of body tissue

Answer 1

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

Question 2

What makes up epithelial tissue?

Answer 2

Epithelial cells and glands

Question 3

What surfaces does epithelial tissue cover?

Answer 3

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

Question 4

What do glands do?

Answer 4

Derived from epithelial cells or attached to them.

Produce fluid secretions

Question 5

Are cells spread or bound tightly in epithelium?

Answer 5

Epithelial cells are bound closely

Question 6

Describe blood supply and regeneration of epithelial tissue

Answer 6

Epithelial tissue is avascualr and receives nutrients thro diffusion or absorption,

Epithelial cells lost or damaged can regenerate and continuously replaced

Question 7

4 functions of epithelial tissue

Answer 7

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

Question 8

Features of each epithelial cell

Answer 8

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

Question 9

How can we classify epithelial tissue?

Answer 9

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)

Question 10

Describe endocrine glands

Answer 10

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

Question 11

Describe exocrine

Answer 11

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

Question 12

Connective tissue

Answer 12

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

Question 13

Describe classification of connective tissue

Answer 13

CONNECTIVE TISSUE PROPER= Loose CT, dense CT and adipose

FLUID CONNECTIVE TISSUE- Blood and lymph

SUPPORTING CONNECTIVE TISSUE- Cartilage and bone

Question 14

Loose connective tissue

Answer 14

Loose collagen and elastic fibres

Fills spaces around organs

Elastic fibres make it resilient - returns to normal shape

Question 15

Adipose tissue

Answer 15

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

Question 16

Dense CT

Answer 16

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

Question 17

Fluid connective tissue

Answer 17

Blood and lymph

Transports cells and dissolved minerals round body

Involved in inflammatory and immune responses

Question 18

Cartilage

Answer 18

On articulate surfaces of joints 
Protects bone 
Shock absorption 
Reduce friction between bones 
Dense packed collagen fibres - withstand pressure

Question 19

Bone

Answer 19

Support
Attachment for skeletal muscles
Flat bones protect internal organs
Has mineral deposits like calcium

Question 20

6 functions of connective tissue

Answer 20

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

Question 21

Describe cartilage in more detail

Answer 21

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

Question 22

WHAT ARE THE 3 types of cartilage ?

Answer 22

HYALINE CARTILAGE

ELASTIC

FIBROCARTILAGE

Question 23

HYALINE CARTILAGE

Answer 23

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)

Question 24

ELASTIC

Answer 24

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

Question 25

FIBROCARTILAGE

Answer 25

Durable and tough
Densely interwoven collagen fibres
Little ground substance
Resist compression and absorbs shock

Found: 
Labrum of joints hip and shoulder 
Intervertebral discs 
Pubic symphysis disc 
Menisci

Question 26

4 membranes in the body

Answer 26

MSCS

Mucous membranes
Serous membranes
Cutaneous
Synovial

Question 27

When do membranes occur?

Answer 27

When epithelial and connectivetissue come together

Question 28

Mucous membranes

Answer 28

Lines passageways like urinary, digestive, respiratory and reproductive

Moist by own secretions like mucus or exposure to fluids like urine or semen

Made of thin layer of epithelial cells - fast absorption and excretion

Question 29

Serous membranes

Answer 29

Line sealed subdivisions of cavities 
Not kept to exterior 
Thin and transparent 
Produces serous fluid to prevent friction between surfaces it covers 
Firmly bonded to organ they cover 

Eg: PPP
Pleura- lines pleural cavity of the lungs
Pleurisy is inflammation of pleura causes breathing issues

Peritoneum- lines abdominal cavity and covers organs there, eg, stomach, spleen and intestines
Peritonitis is inflammation of abdominal lining,

Pericardium-lines pericardial cavity of heart
Pericarditis is inflammation of the heart

Question 30

Synovial membranes

Answer 30

Internal surface of synovial joints

2 layers :
Loose connective tissue
Atypical epithelium = contains macrophages and fibroblasts

Epithelial layer regulates composition of synovial fluid

Hyaline cartilage absorbs nutrients from synovial fluid

Question 31

Cutaneous membranes

Answer 31

Made of epidermis epithelial tissue and dermis connective tissue

Dermis has loose CT and dense irregular. Collagen and elastic fibres. Blood and lymph vessels, nerves, hair follicles and glands

Below dermis is the loose CT layer

Question 32

Functions of cutaneous membrane

Answer 32

Protects underlying tissues and organs against abrasion, fluid loss and chemicals

Excretion of salt, water and organic waste (by glands)

Maintains temperature

Produces melanin (protection from UV) 
Keratin (protects from abrasion and repels water)
Produces vitamin D 3 = supports bone health as absorbs calcium 

Store lipids - adipose tissue
Detects sensations - eg, pressure, touch, vibrations
Coordinate immune response to pathogens and cancers of skin

Question 33

Final facts about skin:

Answer 33

Lip skin is thinner than skin on cheek
More skin layers on palms of hands and plantar surface of the feet
Skin can pucker in water as skin absorbs water by osmosis
Colour of skin indicates issues = blue skin means hypoxia and red means inflammation