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Flashcards in Primary Tissue Types Deck (85)
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1
Q

what is a tissue?

A

a group of specialised cells with a distinct function

2
Q

what are the advantages of tissues?

A

there is a division of labour and coordinated function for tissues which makes larger organisms possible and helps with support and mobility due to the exploitation of resources

3
Q

what does each cell contain?

A

the genome present in the first cell of the embryo

4
Q

what is selective expression?

A

most body cells only express a subset of the genes in the genome to provide distinct characteristics for each cell type

5
Q

examples of cell types in our body…

A

muscle cells - express genes for filamentous contractile proteins actin and myosin
red blood cells - express genes for haemoglobin production then lose all genes and intracellular organelles

6
Q

what is the originator cell called?

A

stem cell

7
Q

what happens to a stem cell?

A

undergoes asymmetric division although the stem cell line continues so there is always a stem cell at the end along with new sets of genes/proteins expressed to produce differentiated cells

8
Q

what is gene expression regulated by?

A

transcription factors

9
Q

what do transcription factors do?

A

act in different combinations to determine the path of differentiation

10
Q

where are stem cells found? (2)

A

early embryo - pluripotent and in tissue - tissue specific

11
Q

what can a totipotent cell do?

A

forms all types of cell at any stage in development

12
Q

what can a pluripotent cell do?

A

make a number of different cells but not all and gives rise to all cell types in the adult body

13
Q

what are the 4 basic types of body tissue?

A

epithelia, connective tissue, muscle, neural tissue

14
Q

what is an organ?

A

a number of tissues grouped together

15
Q

different cell types will have different… (5)

A

shape, organelles and surface structures, binding and association between cells, arrangement and location of cells and extracellular components

16
Q

what do epithelial tissues do?

A

cover surfaces with sheets of cells

17
Q

what is the function of epithelial cells? (5)

A

secretion, absorption, transport, barrier/protection, strength/support

18
Q

what do burns to the skin do?

A

cause loss of skin barrier function with the dangers being fluid loss and infection

19
Q

epithelial tissue characteristics… (4)

A

cover surfaces but vary in shape, show surface modifications/adaptations eg microvilli/cilia, bound to each other by specialised junctions and adhesion molecules, sit on specialised layer of extracellular matrix - basement membrane

20
Q

what junctions exist between epithelial cells? (4)

A

tight junctions, desmosomes, gap junctions and adherens junctions

21
Q

what is the function of a tight junction?

A

sealing

22
Q

what is the function of a desmosome?

A

strengthen cell links

23
Q

what is the function of a gap junction?

A

connect cytosols of adjacent cells for very small molecules

24
Q

what is the function of an adherens junction?

A

spots of connection linking movement proteins eg actin

25
Q

what is the purpose of nervous tissue?

A

collects, processes/integrates and sends information (for local and distant cellular communication)

26
Q

what is a neurone?

A

separate elongated secretory cells that secrete signals by exocytosis at the apex/axon for the dendrite/base to receive information on the next neurone

27
Q

how do synaptic vesicles release chemical signals?

A

exocytosis

28
Q

the post synaptic membrane has…

A

receptors that can pass on/inhibit signals

29
Q

what does an axon do?

A

directs stimulus away from cell

30
Q

what does a dendrite do?

A

directs stimulus towards cell

31
Q

secretion occurs…

A

at the end of axons into specialised intercellular gaps called synapses

32
Q

what is an exon ending bulb?

A

the site of chemical neurotransmitter release

33
Q

what is myelination?

A

the production/development of a myelin sheath around an axon

34
Q

the myelin sheath is..

A

discontinuous with periodic gaps

35
Q

what is an internode?

A

the fatty sheaths surrounding the axon

36
Q

what is a node of Ranvier?

A

the gap between internodes

37
Q

what is the purpose of myelination?

A

enhances conduction

38
Q

peripheral nervous system myelination…

A

one Schwann cell builds one internode

39
Q

central nervous system myelination…

A

one oligodendrocyte builds a number of internodes

40
Q

what are the 4 glial cells of the CNS?

A

oligodendrocytes (myelination), astrocytes, microglia, ependyma (lining of CNS cavities)

41
Q

what are the 2 glial cells of the PNS?

A

Schwann cells (myelination) and satellite cells (support cells in ganglia)

42
Q

what are astrocytes (star cells) for?

A

metabolic and mechanical support that are also in star tissue

43
Q

what do microglial ells do?

A

they are the macrophages of the CNS system and perform phagocytosis and antigen presentation on dying neuron or glial cell

44
Q

what is skeletal muscle?

A

striated and coordinates contraction that is voluntary (reflexes)

45
Q

what is cardiac muscle?

A

striated, coordinated contraction that is involuntary

46
Q

the strong junctions in the intercalated discs of cardiac muscle…

A

allow ionic/structural linkages that allow cells to work and contract together (heartbeat)

47
Q

features of smooth muscle… (4)

A

non-striated and produces coordinated contraction, involuntary, cells are spindle shaped although borders are rarely seen, no striking ordered arrays of actin or myosin

48
Q

what is smooth muscle responsible for? (6)

A

peristalsis in gut, urinary, reproductive, gut and respiratory systems and blood vessels

49
Q

what are examples of connective tissues? (4)

A

fibrocollagenous tissues
cartilage, bone, teeth
adipose tissue (white fat)
blood

50
Q

what is a major feature of connective tissue?

A

is a mix of different cells and extracellular matrix

51
Q

what does the extracellular matrix contain? (3)

A

fibrous protein
structural carbohydrates and protein
mineral deposits

52
Q

what is the function of connective tissue? (4)

A

strength, support, cushioning, flexibility

53
Q

where is loose fibrocollagenous tissue found?

A

around epithelia/organs

54
Q

loose fibrocollagneous tissue…

A

is made of type 1 collagen and is surrounded by lots of cells, water and structural carbohydrates

55
Q

where is dense fibrocollagenous tissue found?

A

tendons and ligaments

56
Q

dense fibrocollagneous tissue…

A

is made of type 1 collagen

57
Q

where is reticular fibrocollagneous tissue found?

A

liver and lymph nodes

58
Q

reticular fibrocollagneous tissue…

A

is made of type 3 collagen

59
Q

what are the cells in fibrocollagenous tissue? (6)

A

fibroblasts, macrophages, mast cells, plasma cells, stem cells, blood cells and adipocytes

60
Q

fibroblasts synthesise…

A

fibrous proteins eg collagen, elastins and extracellular matrix components

61
Q

name an exracellular matrix component?

A

proteoglycans

62
Q

macrophages…

A

phagocytose foreign bodies/organisms and present antigens to stimulate immune cells

63
Q

mast cells synthesise…

A

histamine and other mediators of inflammation

64
Q

plasma cells synthesise…

A

antibodies (mature B cells)

65
Q

stem cells replace and regulate…

A

fibroblast and other cell numbers

66
Q

what does cartilage do?

A

brings flexibility, smooth joint movement and strength

67
Q

cartilage types… (3)

A

elastic, hyaline, fibrocartilage

68
Q

properties and examples of elastic cartilage…

A

flexible made of elastin and found in external ear

69
Q

properties and examples of hyaline cartilage…

A

impact resistant, durable, low friction found in joint surfaces and trachea

70
Q

properties and examples of fibrocartilage…

A

strong made of collagen 1 and found in invertebral discs, knee joint menisci

71
Q

composition of hyaline cartilage…

A

composed of chondrocyte cells with the extracellular matrix being proteoglycans, collagen (mainly type 2), 60-80% weight in water but no blood vessels

72
Q

purpose of bone… (3)

A

skeletal support, mineral store (calcium) and blood formation

73
Q

what is trabecular bone?

A

long bone head

74
Q

what is compact bone?

A

long bone cylinder

75
Q

what are the cells involved in maintaining bone called?

A

osteocytes - embedded in bone structure

76
Q

what does bone’s extracellular matrix contain? (3)

A

framework of collagen fibres mineralised with calcium salts, proteoglycans, blood vessels

77
Q

how is compact bone arranged?

A

cylindrically in Haversian systems

78
Q

what is an osteoclast?

A

large macrophage-like cell that digests bone

79
Q

what is an osteoblast?

A

used for bone formation and laying down framework and becomes trapped as osteocytes

80
Q

what is white fat for?

A

energy storage, insulation protection

81
Q

what is brown fat for?

A

heat production

82
Q

white cell composition…

A

a single droplet of fat occupies most of the cell and the nucleus and cytoplasm is squeezed into the periphery of the cell

83
Q

what does leptin do?

A

signals the brain that the body has had enough to eat

84
Q

how does brown fat make heat?

A

by uncoupling oxidative phosphorylation in mitochondria

85
Q

properties of brown fat and its placement in the body?

A

contains multiple globules of fat and is located in the upper trunk region