Types of Tissues

Question 1

What are the four main types of tissues?
What components exist in tissues?

Answer 1

Epithelial; connective; nervous; muscle.
Cells, fibres and extracellular substance.

Question 2

Where are simple squamous cells found and what is their function?

Answer 2

Air sacs; lining of the heart; blood vessels.
Thin for diffusion and filtration.

Question 3

Where are simple cuboidal cells found and what is their function?

Answer 3

In ducts of glands; kidney tubules.
Secretion and absorption.

Question 4

Where are simple columnar cells found and what is their function?

Answer 4

Ciliated tissues in the bronchi; smooth in the digestive tract.
Secretion and absorption.

Question 5

Where are pseudostratified columnar cells found and what is their function?

Answer 5

Ciliated tracheal tissue.
Secretion and movement of mucus.

Question 6

Where are stratified squamous cells found and what is their function?

Answer 6

Lines the oesophagus and mouth.
Protection against abrasion.

Question 7

Where are stratified cuboidal cells found and what is their function?

Answer 7

Sweat glands, salivary glands, mammary glands.
Protection.

Question 8

Where are stratified columnar cells found and what is their function?

Answer 8

The male urethra and the ducts of some glands.
Secretion and protection.

Question 9

Where are transitional cells found and what is their function?

Answer 9

Lines the bladder and urethra.
Allows the urinary organs to expand and stretch.

Question 10

What specialisations do epithelial cells have?

Answer 10

They have junctional complexes that keep the cells close together. They have cell surface projections (cilia and microvilli).

Question 11

Describe exocrine glands.

Answer 11

Remains in contact with epithelium by ducts; secretes into the lumen of tubes.

Question 12

Describe endocrine glands.

Answer 12

No contact with epithelium; secretes into blood vessels.

Question 13

Describe how exocrine glands are classified.

Answer 13

Unicellular and multicellular.
Simple (tubular and acinar) and compound (tubuloacinar).
Mucous and serous.

Question 14

Describe the differences between mucous and serous secretions.

Answer 14

Mucous is rich in proteoglycans. Pale staining. Has peripheral flattened nuclei. Found in the trachea.
Serous is watery, and has enzymes and proteins. Dark staining. Has rounded, more central nuclei. Found in the pancreas.

Question 15

Describe the mechanisms of exocrine secretion.

Answer 15

Merocrine - secretes from the cell. Sweat glands.
Apocrine - cells are pinched off. Mammary glands.
Holocrine - cell dies and secretes itself. Sebaceous glands.

Question 16

Describe myoepithelial cells.

Answer 16

Expels secretions from the lumen of glands. Has contractile functions.

Question 17

Describe epithelial tissue.

Answer 17

Cell rich. Found on the surface. Lies on a basement membrane.

Question 18

Describe connective tissue.

Answer 18

Few cells. Connects and supports. Spaces are filled with fibres, ground substance and fluid (ECM).

Question 19

Describe areolar tissue.

Answer 19

Loose CT. Found under the skin. The initial site of defence against bacteria.

Question 20

Describe adipose tissue.

Answer 20

Loose CT. An abundance of fat-storing adipocytes. Found under the skin; between internal organs; and inner bone cavities.
White fat is adult. Brown fat is foetal.

Question 21

Describe dense irregular tissue.

Answer 21

Collagen fibres run in all directions. Found in the dermis of the skin, and fibrous capsules of organs and joints. Has structural strength.

Question 22

Describe dense regular tissue.

Answer 22

Collagen fibres run in one direction. Ligaments and tendons. Can withstand great tensile stress.

Question 23

Give examples of specialised connective tissue.

Answer 23

Cartilage. Bone. Blood.

Question 24

What components exist in the ECM?

Answer 24

Fibres (collagen, elastic, reticular).
Ground substance (carbohydrates linked to proteins).
Tissue fluid.

Question 25

What cells exist in connective tissue?

Answer 25

Fibroblasts (synthesises ECM and collagen).
Macrophages; adipocytes; mast cells; undifferentiated cells; and WBCs.

Question 26

Describe nervous tissue.

Answer 26

Used for communication.
Angular-shaped neurones.
Surrounded by satellite cells.
Receives, generates and transmits electrical signals.

Question 27

Describe muscle tissue.

Answer 27

Elongated thin cells.
Cytoplasms packed with contractile apparatus.
Shortens lengths and closes spaces.

Question 28

Describe skeletal muscle.

Answer 28

Attaches to skeleton - voluntary.
Striated (highly ordered arrangement of contractile proteins).

Question 29

Describe cardiac muscle.

Answer 29

Found in heart - involuntary.
Striated and branched (less highly ordered).

Question 30

Describe smooth muscle.

Answer 30

Found in organs - involuntary.
Non-striated (randomly ordered).