Soft Tissue Structure, Function And Healing Flashcards
What are the 4 types of tissues?
Epithelial
Connective
Muscle
Nerve
Describe epithelial tissue
Covers exposed surfaces Lines internal passageways and chambers Forms glands Cells in close association Forms a barrier between organism and environment
Examples of epithelial cell locations
Oesophagus, skin, stomach, intestine, blood vessels
What are the 4 functions of Epithelial tissue?
Physical protection
Control permeability
Provide sensation
Produce specialised secretions
What are the two types of glands epithelial cells form?
Exocrine
Endocrine
Describe an exocrine gland
Not part of the endocrine system
Secrete products into ducts that empty onto a surface
E.g. sweat glands, salivary glands, digestive glands.
Describe an endocrine gland
Ductless glands
Secrete hormones into cellular spaces that then enter the blood stream
Travel to a specific receptor on a target cell
E.g. thyroid gland, adrenal gland, pituitary gland, endocrine gland
How many types of connective tissue are there, and what are they?
6 Loose connective Fibrous (Dense) connective Adipose Cartilage Bone Blood
What are the properties of connective tissue?
Fill internal spaces Provide other tissue support Transport materials Store energy Connects epithelium to rest of the body Forms a framework
What are the functions of connective tissue?
Provides structure Transports Protects Supports Stores energy and defends
What are the 3 classifications of connective tissue?
Proper connect tissue
Fluid connective tissue
Supporting connective tissue
Describe cartilage
Closed pack network of collagen and elastic fibres embedded in a firm matrix gel.
What is cartilage made of?
Chondrocytes - only cells found in healthy cartilage. Produce and maintain the collagen matrix.
Proteoglycans - proteins which attach to other substances within the body.
In cartilage they’re called Aggrecans and they provide hydration and swelling pressure which allows tissues to withstand compressive forces.
What are the 3 types of cartilage?
Hyaline
Elastic
Fibrocartilage
Describe hyaline cartilage
Most common Closed pack matrix Collagen fibre Tough but flexible Most joint surfaces Between ribs and sternum
Describe elastic cartilage
Numerous elastic fibres
Resilient but flexible
In the external flap of the ear
Small cartilages in larynx
Describe fibrocartilage
Densely interwoven Collagen fibres Durable and tough Resists compressive forces Absorbs shock Forms the knee menisci Between pubic bones Between spinal vertebrae
What does a mix of epithelial and connective tissue make?
Membranes
What is a membrane?
A selective barrier that allows some substances to pass through and stops others.
What are the four types of membrane?
Synovial
Serous
Mucous
Cutaneous
Describe a mucous membrane
Epithelial and connective tissue
Lubricated by muscles or exposure to fluids
Line passageways that connect with the exterior
Moist surface to reduce friction and facilitate secretion
E.g. respiratory tract
Describe a serous membrane
Line sealed, internal divisions of body cavities
Not open to the exterior
Very thin and transparent
Firmly attached to body walls and organs
Fluid between Them
Minimises friction between cavities
Describe a synovial membrane
Connective tissue with a layer of fibroblasts and macrophages
These control the composition of synovial fluid
Articulate cartilage must be lubricated
Movement of a joint is essential for formation and circulation of synovial fluid
Movements cause production of synovial fluid
Describe a cutaneous membrane
Many layers of squamous epithelial cells
Epidermis and dermis layers
Epidermis - thick layers of superficial epithelium
Sermon - underlying area of types of connective tissue
Found at accessory structures such as hair, nails and exocrine glands
Describe the skin
Barrier composed of elastic and collagen fibres
Contains lymphatic vessels, blood vessels and nerves
Contains hair follicles and glands
What are the functions of the skin?
Protection Excretion Maintenance Production Detection
What is a sprain?
A stretch or tear of a ligament
How many grades of a sprain are there? What do they involve?
3
Grade 1 - stretching and small tears
Grade 2 - incomplete tear
Grade 3 - complete tear
What is a strain?
Muscle or tendon injury that involves over stretching or over contracting and lengthening.
Which tears the collagen
What are some classifications of a grade 1 sprain and or strain?
Localised pain and tenderness No visible bruising Minimal swelling Minimal loss of function No loss of strength or range of muscle movement No ligament laxity
What are some classifications of a grade 2 sprain and or strain?
Poorly localised pain Bruising Moderate swelling Disability and painful Range of motion deficit Decrease in muscle strength Ligament may of caused an unstable joint
What are the common classifications of a grade 3 sprain and or strain?
Joint instability
Inability of the muscle to contract
Immediate acute pain
Audible pop, crack or click
What are some factors that cause tissue damage?
Injury - physical, thermal, electrical, chemical
Infection - viruses, bacteria, fungi
Infarction - obstructions of blood supply to an organ, starving it of o2
Immune responses - auto immunity or foreign protein hypersensitivity
What are the two types of body tissue?
Parenchymal tissue - control the functioning of cells of that organ
E.g. cardiac myocyte tissue = heart
Hepatocyte tissue = liver
Interstitial tissue - supports connective tissue
Contains cells that support organs
Blood vessels and nerves are made of this
What are the 3 types of tissue healing?
Resolution
Regeneration
Replacement
Describe resolution
The rapid healing of mild injury
Removal of debris associated with the inflammatory response which is sufficient to restore tissue to its normal state
Epithelial cells shed and regenerate without incident
Removes the inflammation
Describe regeneration
Specialised tissue is replaced by the making of surrounding undimmed specialised cells
Growth factors are released from damaged tissues and cells - cytokines and platelet derived growth factor that increase mitogenic activity = Mitosis
Injured tissue replaced with parenchymal cells
Describe replacement
Deals with severely damaged tissue or non-regenerable tissue
Healed by laying down connective tissue known as scarring
Replaced by granulation tissue = scar tissue.
Original tissue is not replaced by the same tissue.
What are the three types of cells?
Labile cells - continually divide to regenerate tissue
Stable cells - stop growing once growth stops. Will be stimulated when growth and division is needed. Such as if damage occurs and a supportive framework is needed
Fixed non-dividing cells - can’t regenerate or divide or undergo mitosis. Such as the cardiac and skeletal muscle. Once damaged can not repair so left with scar tissue.
How many stages are there in connective tissue repair? What are they?
4 Bleeding Inflammatory Proliferation Remodelling
What is primary intention?
Occurs where the tissue surfaces have been closed.
With stitches, staples, glue, tapes
Used when there have been minimal tissue loss
What is secondary intention?
Wound that is extensive and involves considerable tissue loss, where the edges cannot be brought together so it heals in this manner, forming scar tissue.
How ulcers heal.
How is primary intention different from secondary intention?
Longer repair time
Scarring is greater
Chances of infection are greater
What is tertiary intention?
Known as delayed or secondary closure
Indicated when there is reason to delay closing a wound due to poor circulation to the area etc.
They require more connective tissue - scar tissue
What are some factors that affect wound healing?
Nature of injury Temperature Drugs Age Blood flow Infection
What are some complications of tissue repair?
Infection - invasion can affect and delay the repair process
Ulceration - open, crater like lesions of the skin
Dehiscence - scar formation and wound separation
Keloid Development - hypertrophic scars due to excessive collagen production
Adhesion - fibrous connection between cavities and scar tissues
