Connective Tissue

Question 1

Connective tissue

Answer 1

Most abundant tissue in the body. Cells in this tissue are more widely separated from eachother than in epithelial tissue. Intercellular substance (matrix) is present in considerably larger amounts.
Usually fibres present in the matrix, which may be of a semi-solid jelly-like consistency or dense and rigid, depending on the position and function of the tissue. The fibres form a supporting network to which the cells attach. Most types of connective tissue have a good blood supply. Functions of connective tissue are binding and structural support, protection, transport, insulation.

Question 2

Types of calls in connective tissue

Answer 2

Fibroblasts
Fat cells (adipocytes)
Macrophages
Leukocytes
Mast cells

Question 3

Fibroblasts

Answer 3

Large cells with irregular processes. Manufacture collagen and elastic fibres.
Partially active in tissue repair when they bind together the cut surfaces of wounds, or form granulation tissue following tissue destruction. Collagen fibres formed during wound healing shrink as they age, sometimes interfering with the functions of the organ involved.

Question 4

Fat cells

Answer 4

Occur singly or in groups in many types of connective tistre and are especially abundant in adipose tissue. Vary in size and shape according to the amount of fat they contain.

Question 5

Macrophages

Answer 5

Large, irregular -shaped cells with granules in the cytoplasm. Someone fixed and some are mobile. They are phagocytic, engulfing and digesting cell debris, bacteria and other foreign bodies.

Question 6

Leukocytes

Answer 6

White blood cells, normally found in small numbers in healthy connective tissue but neutrophils migrate in significant numbers during infection when they play an important part in tissue defence. Plasma cells develop from a type of white blood cell. They synthesise and secrete specific defensive antibodies into the blood and tissue.

Question 7

Mast cells

Answer 7

Found in loose connective tissue under the fibrous capsule of some organs. Their cytoplasm is packed with heparin, histamine and others, which are released following tissue damage. Heparin prevents coagulation of blood, helping to maintain blood flow though inflamed tissues.

Question 8

Loose (areolar) connective tissue

Answer 8

Most generalised type. Semisolid matrix with many fibroblasts and some fat cells, mast cells and macrophages, widely separated by elastic and collagen fibres. Found in almost every part of the body, providing elasticity and tensile strength
Under the skin, between muscles, supporting blood vessels and nerves, in the alimentary canal, in glands supporting secretory cells.

Question 9

Adipose tissue

Answer 9

Consists of adipocytes containing large fat globules, in a matrix of areolar tissue. White makes up 20-25% of body weight in adults. More present in obese. Secretes leptin. Supports kidneys and eyeballs, also found between muscle fibres and under the skin where it acts as a thermal insulator and energy store.
Brown adipose has more mitochondria and a more extensive capillary network than white. Generates more heat when broken down, important in newborns. Found in small amounts in adults in upper chest and neck area.

Question 10

Reticular tissue

Answer 10

Has a semisolid matrix with fine, branching reticulin fibres. Contains reticular cells and White blood cells. Found in lymph nodes and lymphatic organs.

Question 11

Dense connective tissue

Answer 11

Contains more fibres and fewer cells than loose connective tissue.

Question 12

Fibrous tissue

Answer 12

Made of closely packed bundles of collagen fibres with very little matrix. Fibrocytes are few in number and lie in rows between the bundles of fibres.
Forms ligaments, outer protective covering of bones called periosteum. Outer protective covering of kidneys, lymph nodes and the brain. Forming muscle sheaths called fascia, which extend beyond the muscle to become the tendon that attaches the muscle to bone.

Question 13

Elastic tissue

Answer 13

Capable of extension and recoil. Few cells. Matrix mainly elastic fibres secreted by fibroblasts. Found where stretching is required - blood vessel walls, lungs

Question 14

Blood

Answer 14

Is a connective tissue

Question 15

Cartilage

Answer 15

Firmer than other connective tissues. The cells are sparse and embedded in matrix, reinforced by collagen and elastic fibres. 3 types; hyaline, fibrocartilage, and elastic fibrocartilage.

Question 16

Hyaline cartilage

Answer 16

Provides flexibility, support and smooth surfaces for movement at joints.
On the ends of long bones that form joints. Costal cartilage, attaching ribs to sternum. Forms part of larynx, trachea and bronchi.

Question 17

Fibrocartilage

Answer 17

Tough, slightly flexible
Between the vertebrae, called intervertebral discs.
Between articulating surfaces of bones of the knee, called semilunar cartilages
On the rim of the bony sockets of the hip and shoulder joints, deepening the cavities without restricting movement.

Question 18

Elastic fibrocartilage

Answer 18

Provides support and maintains shape of the lobe of the ear, the epiglottis, and part of the tunica media of blood vessels.

Question 19

Bone

Answer 19

Osteocytes are surrounded by a matrix of collagen fibres strengthened by inorganic salts, especially calcium and phosphate. Compact bone is more dense and solid. Spongy bone has more of a honey comb appearance.