Connective tissue Flashcards
What does connective tissue encompass?
Forms all other types of tissue e.g bone cells, blood, fat and fibres
Connective tissue
Widely spread cells
Variability in vascularity between CT types due to different cells
Extracellular matrix
Consists of ground substance and fibres
Ground substance
Consists of water and large molecules like hyauronic acid and proteoglycans
Matrix fibres
Includes collagen, reticular and elastic
Different types of cells
Fibroblasts Osteoblasts/osteocytes (bone) Chondroblasts/ chondrocytes (Cartilage) Red and white blood cells (macrophages; mast cells and plasma cells Adipocytes (fat cells)
Functions of connective tissue
Binding organs Support Physical protection Storage Transport
Example of binding organs
Tendons bind muscles to bone
Example of support
Bones of the skeletal system provide rigid support for the body
Example of Physical protection
Vertebral column protects the spinal cord and fat cushions organs like kidneys
Example of Storage
Adipose tissue stores the bodies major energy reserve and bones provide storage from minerals like calcium
Example of Transport
Blood transports like gases, nutrients, hormones and wastes throughout the body
Fibroblasts
Secrete fibres of this tissue
Macrophages
Engulf cell debris, foreign matter, and micro-organisms in coherence with the immune response
Adipocytes
Store lipids (fat cells)
Plasma cells
Secrete antibodies in response to infection
Mast cells
Found next to capillaries, involved in infection response and allergic reactions
Reticular fibres
Smaller form of collagen, support small cel groups of blood forming tissues, lymphatic tissues and adipose tissues
Collagen
Linkages of protein exhibiting great tensile strength
Elastic fibres
Made of protein elastin
Types of connective tissue
Areolar Reticular Adipose Regular irregular Cartilage Bone (osseous) Blood and lymph
Areolar (loose fibrous connective tissue)
Loose arrangement of fibres and cells (fibroblasts, macrophages, mast cells, plasma cells, fat cells and some white blood cells) in abundant group substance
Areolar (loose fibrous connective tissue) locations
Underlies all epithelia, between muscles, passageways for nerves and blood vessels
Areolar (loose fibrous connective tissue) functions
Stretch and flexible connection
Reticular (loose fibrous connective tissue)
Loose network of reticular fibres and cells)
Forms supportive stroma (framework) for lymphatic organs
Reticular (loose fibrous connective tissue) locations
Lymph nodes
Spleen
Thymus
Bone marrow
Reticular (loose fibrous connective tissue) function
Defence against microorganisms and other injurious substances
Reticular meshwork filters out injurious particles, and reticular cells phagocytose them
Adipose (loose fibrous connective tissue)
Contains mostly fat cells (adipocytes) and some fibroblasts, macrophages and mast cells
Adipose (loose fibrous connective tissue) functions
Acts as food (energy) reserve, support, protection, insulation (white fat) and heat generation (brown fat)
Produces the hormone leptin, which signals to the brain how much fat is stored
Regular (dense fibrous tissue)
Matrix consists mainly of densely packed fibres in regular parallel rows and has relatively few fibroblasts
Types of regular (dense fibrous tissue)
Collagenous
Elastic
Collagenous regular (dense fibrous tissue)
Mostly collagenous fibres in the extracellular matrix
e.g tendons and ligaments
Elastic regular (dense fibrous tissue)
Mostly elastic fibres in the extracellular matrix
e.g arteries
Irregular (dense fibrous tissue)
Densely packed, randomly arranged, collagen fibres and few visible cells
Withstands stresses applied in different directions
Irregular (dense fibrous tissue) locations
Deeper layer of skin; Capsules around organs
Cartilage tissue
Supportive connective tissue with flexible rubbery matrix
Avascular
Type of cell in Cartilage tissue and its role
Chondrocytes
Produce fibres and the ground substance of cartilage
Perichondrium
Membrane that surrounds the cartilage
Types of fibres in cartilage
Hyaline
Fibrocartilage
Elastic cartilage
Hyaline roles
Most prevalent type
Supports airway
Eases joint movement
Hyaline composition
Rubbery matrix;
Dispersed collagen fibres
Clustered chondrocytes in lacunae (gap)
Hyaline locations
Ends of bones at movable joints (articular cartilage)
Sternal ends of ribs
Supportive material in larynx (voice box)
Trachea
Bronchi
Foetal skeleton
Fibrocartilage
Strongest and most durable type of cartilage
Serves as shock absorbing material between bones
Fibrocartilage locations
Between bones at the knee (meniscus)
In intervertebral disks and pubic symphysis
Elastic cartilage
Hyaline cartilage containing many fine elastic fibres
Provides strength and flexibility
Elastic cartilage locations
External ear and epiglottis
Bone (osseous) tissue
Hard connective tissue that consists of living and mineralised matrix (specialised crystals called hydroxyapatite which contains calcium and phosphate)
Blood and lymph (liquid connective tissue)
Consists of cells suspended in extracellular matrix that is a liquid e.g in blood the extracellular matrix is called blood plasma
Blood and lymph locations
Found in heart, blood vessels and lymphatic vessels
