Soft Tissue Structure, Function & Healing

Question 1

Four types of tissue

Answer 1

Connective
Epithelial
Muscle
Nervous

Question 2

Epithelial tissue…

Answer 2

Includes epithelia and glands
Cover internal or external surfaces
Cells bound closely together
Has an exposed surface
Are avascular
Cells continuously regenerating

Question 3

Epithelial tissue functions

Answer 3

Physical protection: from abrasion, dehydration and destruction

Control permeability: substances leaving or entering body cross epithelium, Variable permeability , absorption, secretion, excretion, diffusion

Provide sensation: sensory nerve supply, smell, taste, hearing, sight

Provide info on internal/ external environment
Produce specialised secretions: produced by glands

Question 4

Structure of epithelial cells

Answer 4

Coated in microvilli and cilia, lateral surfaces, Golgi apparatus, nucleus, mitochondria, basal surface

Question 5

Endocrine glands

Answer 5

Secrete hormones into cellular spaces then blood
Hormones regulate or co ordinate activities of various tissues, organs and systems

Examples: pituitary, thyroid, thymus

Question 6

Exocrine glands

Answer 6

Secrete products into ducts that empty onto the epithelial surface

Examples: digestive enzymes, sweat, tears

Question 7

Connective tissue

Answer 7

Throughout the body
Never exposed
Connects epithelial tissue to rest of body
Highly vascular
Fill internal spaces

Question 8

Functions of connective tissue

Answer 8

Structural framework for the body
Transports fluids and dissolved materials
Protects delicate organs
Connects other types of tissue
Stores energy (triglycerides)
Defend body from microorganisms

Question 9

Cartilage is

Answer 9

Closely packed collagen fibres embedded in a firm matrix gel containing chondrocytes & proteoglycans

Question 10

Types of cartalidge

Answer 10

Hyaline cartilage
Elastic cartilage
Fibrocartalige

Question 11

Hyaline cartalige

Answer 11

Most common
Tough but flexible
Found:
Most joints covering articulated surfaces
Between ribs and sternum
Nasal cartalige
Respiratory tract

Question 12

Elastic cartalidge

Answer 12

Numerous elastic fibres
Resilient but flexible
Found:
External flap (auricle)
Epiglottis
Auditory tube
Small cartilages in larynx

Question 13

Fibrocartilage

Answer 13

Densely interwoven collagen fibres
Little ground substance
Durable & tough
Resists compression & absorbs shock
Found:
Between vertebrae
Between pubic bones
Meniscus

Question 14

where do membranes occur?

Answer 14

when epithelial tissue is combined with connective tissue

Question 15

four types of tissue membrane

Answer 15

mucous membrane
serous membrane
cutaneous membrane
synovial membrane

Question 16

mucous membranes

Answer 16

line passageways that lead to exterior i.e digestive, respiratory, urinary & reproductive tracts

epithelial surfaces kept moist to reduce friction and allow secretion/ absorption

thin layer of epithelial cells

Question 17

serous membranes

Answer 17

• line sealed, internal subdivisions of body cavities
• not open to exterior
• very thin and transparent
• firmly attached to body walls & organs that they cover
• minimise friction: serous fluid produced

Question 18

examples of serous membranes

Answer 18

peritoneum: lines peritoneal cavity (abdomen) covers surface of exposed organs peritonitis

pleura: lines pleural cavity, covers the lungs pleurisy

pericardium: lines pericardial cavity,
covers heart pericarditis

Question 19

synovial membranes

Answer 19

around joint cavity of synovial joints, forms synovial capsule

made up of connective tissue with macrophages and fibroblasts

synovial fluid within capsule- lubricates and nourishes hyaline cartilage

movement of joint stimulates formation and circulation of synovial fluid

Question 20

cutaneous membranes (skin)

Answer 20

Two layers
- epidermis (epithelial tissue)
- dermis (connective tissue)

Subcutaneous layer of loose connective tissue
Accessory structures

Question 21

functions of cutaneous membrane?

Answer 21

• protection of underlying tissue
• excretion of salts, water & waste products
• maintenance of temperature
• production of melanin & keratin
• synthesis of vitamin D
• storage of lipids
• sensation
• co-ordination of immune response to pathogens/ cancers in the skin

Question 22

micro-tears

Answer 22

localised pain
tenderness
no visible bruising
minimal loss of function
no laxity

Question 23

partial tear

Answer 23

moderate swelling
bruising
poorly localised pain
impairment and painful ROM
may have some instability

Question 24

complete tear / rupture

Answer 24

audible pop/ acute pain
considerable swelling or bleeding to joint (Haemarthrosis)
significant laxity/ instability

symptoms may later settle

Question 25

muscle & tendon injuries sprain

Answer 25

typically caused by over contracting or lengthening a muscle causing tearing of collagen
most commonly occurs in the eccentric phase of contraction
called a strain

Question 26

factors that cause tissue damage?

Answer 26

injury: physical / thermal / radiational / electrical / chemical
infection: viruses / bacteria / fungi / protozoa
infarction: myocardial infarct
immune reactions: foreign protein hypersensitivity / autoimmune

Question 27

types of body tissue (parenchymal tissue)

Answer 27

• functioning cells of organs
• e.g neuronal (brain) tissue, epithelial (skin) tissue, cardiac myocyte (heart) tissue, hepatocyte (liver) tissue

Question 28

types of body tissue (Stromal (interstitial) tissue)

Answer 28

supporting connective tissues
contains many cell types including fibroblasts
blood vessels
nerves & nerve endings

Question 29

3 Types of tissue healing

Answer 29

1. Resolution
   rapid healing of mild injury
   epithelial cells slough & regenerate
2. Tissue Regeneration
   specialised tissue is replaced by the proliferation of surrounding undamaged specialised cells
   i.e injured tissues are repaired with parenchyma
3. connective tissue repair (replacement)
   lost tissue is replaced by granulation tissue which matures to form scar tissue

Question 30

Resolution healing

Answer 30

occurs in acute inflammatory response to minor injuries or those with minimal effect to parenchymal cell

tissue is restored to prior state

most commonly occurs in epithelial tissue

i.e mild insect bite

Question 31

tissue regeneration

Answer 31

replaces lost cells by division of surviving adjacent cells, also to restore tissue to normal
before it can occur necrotic cells must be removed (using acute inflammatory process)

Question 32

whether tissue regeneration can occur?

Answer 32

• Damaged tissues and cells releasing growth factors to decrease mitogenic activity (mitosis)
•regenerative capacity of involved cells
•number of surviving viable cells
• the presence of a connective tissue framework that will provide a base for normal tissue structure

Question 33

Labile cells regeneration ability?

Answer 33

constant turn over (skin cells)

Question 34

Stable cells regeneration ability?

Answer 34

usually stop growing once growth i.e. liver, kidney & lungs
requires supportive framework if damage occurs

Question 35

Fixed (permanent) non-dividing cells regeneration ability?

Answer 35

cannot undergo mitosis
i.e nerve, muscle & cardiac
tissue repair leaves a scar

Question 36

connective tissue repair stages

Answer 36

acute (hours) : bleeding
acute —> sub acute (days): inflammation
sub acute (days —> weeks) : remodelling
chronic (months): proliferation

Question 37

bleeding phase

Answer 37

occurs following injury
relatively short lived
more vascular tissue bleeds for longer (muscle)
less vascular less volume & duration (ligaments)
average is 4-6 hours but some bleed for much longer

Question 38

inflammatory phase

Answer 38

occurs in first few hours
reaches peak at 1-3 days
resolves in few weeks
changes in blood flow
- oedema exudation of protein rich fluid
- phagocytosis
- lymphatic drainage
- leukocyte emigration

Question 39

proliferation phase

Answer 39

24-48 hours after injury
can take up to a few weeks/ months
fibroblasts, macrophages and blood vessels proliferate to form granulation tissue
two fundamental processes: angiogenesis & collagen synthesis

Question 40

remodelling / maturing phase

Answer 40

begins at 3 weeks can last up to 2 years
continuous remodelling of scar tissue
physical stress is an important influencing factor in this stage

Question 41

factors that affect wound healing

Answer 41

• nature of injury
• site of injury
• temperature
• drugs (steroids)
• ** movement +- (stress)**
• malnutrition
• blood flow and O2 delivery
• infection
• wound separation
• foreign bodies
• age

Question 42

complications of tissue repair

Answer 42

Infection
ulceration
dehiscence
keloid development
adhesion

Question 43

soft tissue healing summary

Answer 43

• sprains affect ligament
• strains affect muscles & tendons
• connective tissue repair has 4 stages
• if wound edges are approximated it will heal by primary intention
• if wound edges are seperate it will heal by secondary intention (same stages but will take longer and create greater scar tissue)