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Flashcards in Tissues Deck (20)
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1
Q

Define epithelium

A

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

2
Q

Describe epithelial tissue

A
  • 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
Q

Describe cell-cell junctions

A
  • desmosomes (adhering junctions) provide firm anchorage
  • tight/occluding junctions seal intracellular spaces
  • gap junctions allow for cell-cell communication
4
Q

What structures are found in cell-ECM junctions?

A

Hemidesmosomes

5
Q

Epithelia have very good

A

regenerative and adaptive powers

6
Q

Function of epithelia depends on

A

the cell itself, not the ECM

7
Q

Cilia allow

A

movement of substances

8
Q

Microvilli allow

A

absorption

9
Q

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

A
  • 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
Q

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

A
  • 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
Q

Describe the epithelial components of the liver

A
  • hepatocytes
  • arranged in rows (or cords) between blood vessels
  • multiple functions including secretion
  • support epithelial cells line blood vessels and bile ducts
12
Q

Describe the epithelial components of the kidneys

A
  • 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
Q

Give three consequences of abnormal function of covering and lining epithelia

A
  • over/under proliferation
  • over/under secretion
  • loss of ciliary beat
14
Q

Define gland

A

collections of multi or single cellular secretory epithelial cells

15
Q

Give the basic functions of glandular epithelium

A

Endocrine - secretes into blood e.g. adrenal cortex

Exocrine - secretes to surface e.g. sweat glands

16
Q

Give two consequences of abnormal glandular function

A

Over production - pituitary giantism

Under production - pituitary dwarfism

17
Q

What fibres are found in connective tissue?

A

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
Q

What ground substances are found in connective tissues?

A
  • proteoglycans
  • hyaluronic acid
  • glycoproteins
19
Q

What types of cell are found in loose connective tissue?

A

Fixed cells - fibroblasts, macrophages, adipocytes, mast cells

Transient cells - WBCs

20
Q

Give four consequences of abnormal function of connective tissues

A

Blood/bone marrow - leukaemia

Loose/dense - loss/abnormal fibers

Cartilage - tear

Bone - osteoporosis