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Flashcards in Tissues Deck (20):
1

Define epithelium

The thin tissue forming the outer layer of a body's surface and lining the alimentary canal and other hollow structures

2

Describe epithelial tissue

- covers surfaces and separates compartments
- has no contact inhibition
- forms cell-cell and cell-ECM junctions to fill any gaps between cells and cover surfaces effectively

3

Describe cell-cell junctions

- desmosomes (adhering junctions) provide firm anchorage
- tight/occluding junctions seal intracellular spaces
- gap junctions allow for cell-cell communication

4

What structures are found in cell-ECM junctions?

Hemidesmosomes

5

Epithelia have very good

regenerative and adaptive powers

6

Function of epithelia depends on

the cell itself, not the ECM

7

Cilia allow

movement of substances

8

Microvilli allow

absorption

9

Give the three types of simple epithelium and an example of each

- squamous e.g. alveoli and capillaries, thin to allow easy diffusion
- cuboidal e.g. lining of nephrons, perform secretion and absorption/pumping
- columnar e.g. lining digestive tract, move mucus when ciliated

10

Give the three types of stratified epithelium and an example of each

- squamous e.g. epidermis, thick and layers can be sloughed off to allow new growth
- cuboidal e.g. ducts of sweat glands, protection
- columnar e.g. pharynx, protection and secretion

11

Describe the epithelial components of the liver

- hepatocytes
- arranged in rows (or cords) between blood vessels
- multiple functions including secretion
- support epithelial cells line blood vessels and bile ducts

12

Describe the epithelial components of the kidneys

- epithelial cells
- arranged into nephrons
- multiple functions including filtration of blood, partial absorption of filtrate
- support cells line blood vessels and renal pelvis which receives toxic urine

13

Give three consequences of abnormal function of covering and lining epithelia

- over/under proliferation
- over/under secretion
- loss of ciliary beat

14

Define gland

collections of multi or single cellular secretory epithelial cells

15

Give the basic functions of glandular epithelium

Endocrine - secretes into blood e.g. adrenal cortex

Exocrine - secretes to surface e.g. sweat glands

16

Give two consequences of abnormal glandular function

Over production - pituitary giantism

Under production - pituitary dwarfism

17

What fibres are found in connective tissue?

Collagen - makes up to 30% body weight, flexible, inelastic with great tensile strength

Elastic fibres - protein elastin, stretch 1.5x length and return to original shape, microfilaments and amorphous component, found in sheets

18

What ground substances are found in connective tissues?

- proteoglycans
- hyaluronic acid
- glycoproteins

19

What types of cell are found in loose connective tissue?

Fixed cells - fibroblasts, macrophages, adipocytes, mast cells

Transient cells - WBCs

20

Give four consequences of abnormal function of connective tissues

Blood/bone marrow - leukaemia

Loose/dense - loss/abnormal fibers

Cartilage - tear

Bone - osteoporosis