Human Anatomy - Connective tissues Flashcards
________ tissue is the most diverse and abundant tissue in the human body.
Connective
What are the main classes of connective tissue?
CTP
Cartilage
Bone
Blood
What are the general functions of connective tissue?
Binding and support Protection and insulation of internal organs Compartmentalization Transportation Major site of body energy reserves
What are key characters of connective tissue?
Few cells
ECM composed of ground substance and fibres.
All connective tissue comes from mesenchyme.
What is ground substance?
Unstructured material that fills the space between cells.
Secreted by the connective tissue cell and determines the tissue’s qualities (solid, liquid, gel)
What do fibres in connective tissue provide?
Support
What are the different fibres in connective tissue?
Collagen fibres, elastic fibres, reticular fibres
Describe collagen fibres.
Tough and resist pulling forces but remain flexible.
Describe elastic fibres
Can stretch up to 150% of relaxed length and return to original shape
Where are elastic fibres abundant?
Skin, blood vessels, lungs
What are reticular fibres?
Thin, fine collagenous fibres that form delicate branching networks.
Strong but allow more “give” than collagen fibres
present in the basement membrane
Draw a key from mesenchyme to the different cells and tissues of the different connective tissues.
Refer to notes. Slide 50
What are the two subclasses of CTP?
Loose connective tissue & Dense connective tissue
Loose connective tissue is further subdivided into?
Areolar & Adipose (And reticular)
Dense connective tissue is further subdivided into?
Dense irregular, dense regular, elastic
What is the ground substance of the ECM in CTP?
gel-like
Which fibres does areolar connective tissue contain?
All three (reticular, collagen, elastic)
What cells are present in areolar connective tissue?
Fibroblasts, macrophages, mast cells, WBCs
What are the functions of areolar connective tissue?
Wrap and cushion organs
Hold and convey tissue fluid
Important role in inflammation/infection
Where is areolar connective tissue located?
Under epithelia
Around organs
Surrounding small nerves and blood vessels
What is interstitial fluid?
(related to areolar)
Tissue fluid derived from leakage of water and small molecules from the blood as it travels through capillaries.
Allows for nutrients and oxygen to be carried to cells and wastes from cells.
Areolar CT soaks up this tissue fluid.
Why is areolar connective tissue considered the main battlefield against infection?
Has immune cells
Prevents penetration of bacteria into the blood
Combination of 3 fibre types serves as a mesh to slow travel of microbes
Describe adipose tissue.
Closely packed adipocytes
Nucleus pushed to the side.
What are the functions of adipose tissue?
Fuel reserve
Insulate against heat loss
Support and protect organs
Where is adipose tissue located?
Under skin (hypodermis) Around kidneys Behind eyeballs In breasts Around the heart
Describe dense irregular connective tissue
Composed of irregularly arranged collagen fibres.
Contains some elastic fibres and fibroblasts.
What is the function of dense irregular connective tissue?
Resist tension exerted in many directions.
Provide structural strength.
Where is dense irregular connective tissue located?
Dermis of skin
Submucosa of GI tract
Fibrous capsules of joints
What is meant by irregular arrangement of collagen fibres
Right angles without a uniform distribution
Describe dense regular connective tissue.
Primarily parallel collagen fibres.
Contains fibroblasts and some elastic fibres.
Poorly vascularized.
Withstands great tension in one direction.
What is the function of dense regular connective tissue?
Attaches muscle to bone (tendon) and bone to bone (ligament)
Where is dense regular connective tissue located?
Tendons and ligaments
Aponeuroses fascia around muscles
Fascia around muscles.
Why does dense regular connective tissue heal slowly?
Poorly vascularized
Describe elastic connective tissue?
Elastic fibres predominate
What is the function of elastic connective tissue?
Allows recoil after stretching.
Where is elastic connective tissue?
Within walls of arteries and aorta, certain ligaments and, surrounding bronchial tubes
Describe cartilage.
Firm, flexible tissue Contains no blood vessels or nerves Blood supply comes from surrounding periosteum Matrix is mostly water Gel-like ECM
What are the cells of cartilage?
Chondroblasts, chondrocytes
What are the fibre types of hyaline cartilage?
collagen
What do chondroblasts do in hyaline cartilage?
Produce matrix
What do chondrocytes do in hyaline cartilage?
Chondrocytes lie in lacunae, maintain metabolism of cartilage.
What is the function of hyaline cartilage?
Supports and reinforces
Cushions
Resists repetitive stress
Where is hyaline cartilage located?
Fetal skeleton
Ends of long bones
Costal cartilage of ribs
Cartilages of nose, trachea, larynx
What are the fibre types of elastic cartilage?
Collagen and elastic
What is the function of elastic cartilage?
Maintains shape of structure
Allows great flexibility
Where is elastic cartilage located?
Supports external ear (pinna)
Epiglottis
What is the basis of cauliflower ear?
Abrasion from punches or rubbing causes breaking of cartilage which, due to lack of blood supply, doesn’t heal
What are the fibres of fibrocartilage?
Collagen
matrix less firm
What is the function of fibrocartilage?
Tensile strength and ability to absorb compressive shock.
Where is fibrocartilage located?
Intervetebral discs
Pubic symphysis
Discs of knee joint (menisci)
What is the matrix of cartilage?
Gel-like
Describe Scurvy.
Occurs due to vitamin D deficiency which is necessary for proper cross-linking of molecules which make up collagen fibres.
Collagen necessary for holding teeth in their sockets.
Symptoms include loss of teeth, blood vessel rupture, poor healing.
