ToB 2 Epithelia Flashcards

1
Q

Define epithelia:

A

Sheets of contiguous cells, of varied embryonic origin, which cover the external surface of the body, and line internal surfaces.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which 3 interior spaces in the body have epithelial linings, and are open to the exterior?

A

1) Gastrointestinal tract 2) Respiratory tract 3) Genitourinary tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which 5 interior spaces do not open to the exterior but have epithelial linings?

A

1) Peritoneum 2) Pleural sac 3) Pericardial sac 4) Blood vessels 5) Lymph vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the peritoneum?

A

The epithelial membrane lining the cavity of the abdomen and covering the abdominal organs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are pleural sacs?

A

The epithelial double membrane which covers a lung.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a pericardial sac?

A

The epithelial double membrane which encases the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 3 embryonic germ layers which form the trilaminar embyonic disk?

A

1) Ectoderm 2) Mesoderm 3) Endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which embryonic germ layer creates skin?

A

Ectoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

From which embryonic germ layer does the GI tract epithelium derive?

A

Endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which main 6 epithelia are derivatives of the embryonic mesoderm layer?

A

1) Blood vessels lining 2) Lymph vessels lining 3) Pericardial sac lining 4) Pleural sacs lining 5) Peritoneum lining 6) Epithelium of urogenital tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

From which embryonic germ layer does the respiratory tract derive?

A

Endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What word describes an epithelium which is one cell thick?

A

Simple

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does ‘compound epithelium’ mean?

A

Epithelium consists of more than one layer of cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define pseudostratified epithelium:

A

An epithelium which is one cell thick, but gives the appearance of a stratified epithelium due to the position of the cell nuclei.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is meant if a cell is described as ‘squamous’?

A

Very thin and flat, such that the cells nucleus creates a bump in the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What type of cells make up the basement membrane?

A

The basement membrane is a non-cellular layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Define basement membrane:

A

A thin, delicate non-cellular membrane which separates an epithelium from underlying tissue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is the basement membrane sometimes thicker than usual?

A

Reticular cells may produce type III collagen, which thickens the basement membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the name of the membrane to which epithelial cells adhere?

A

Basement membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which part of an epithelial membrane acts as a cellular and molecular filter?

A

Basement membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the (often used) Latin name for the basement membrane?

A

Basal lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What name is given to the simple squamous epithelium lining of all vascular elements?

A

Endothelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a mesothelium?

A

The simple squamous epithelia which line the pericardial sac, pleural sacs and the peritoneum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the upper respiratory tract epithelia:

A

Ciliated pseudostratified epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the epithelium lining the loop of Henle:

A

Simple squamous epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Give 2 examples of simple squamous epithelia in the kidney:

A

1) Lining of the loop of Henle 2) Bowman’s capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 4 main functions of a simple squamous epithelium?

A

1) Barrier 2) Gas exchange 3) Active transport (pinocytosis) 4) Lubrication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How would you describe an epithelium which is one cell thick, where each cell is (roughly) as tall as it is wide?

A

Simple cuboidal epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What type of cells line the thyroid gland follicles?

A

Simple cuboidal epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What type of cells line the collecting ducts of the kidney?

A

Simple cuboidal epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which hormone do the epithelial cells lining the collecting duct of the kidney respond to?

A

Anti-diuretic hormone (ADH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What type of epithelia line the surface of an ovary?

A

Simple cuboidal epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Small ducts of many exocrine glands are lined by what type of epithelia?

A

Simple cuboidal epithelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What 2 functions must the epithelium of a kidney tubule have?

A

1) Absorption 2) Secretion

35
Q

What type of epithelial cell line the Crypts of Liebekuhn in the intestine?

A

Simple columnar epithelia

36
Q

In what position do you usually find the nuclei of columnar cells?

A

In the basal half of the cell (near basement membrane)

37
Q

What type of cells line the gall bladder?

A

Simple columnar epithelia

38
Q

What is the main function of the gall bladder epithelial cells?

A

Absorb water and electrolytes from bile (produced by liver)

39
Q

What is meant by a striated epithelial cell?

A

The basal membrane of the cell is extensively infolded

40
Q

Where can you find a striated simple columnar epithelium?

A

In part of the parotid salivary gland

41
Q

What type of cells line the fallopian tube of the uterus?

A

Simple columnar epithelia (sometimes ciliated)

42
Q

On a cell with microvilli, approximately how many microvilli are found on each cell?

A

~ 1000 microvilli/cell

43
Q

What type of protein can bind adjacent plasma membranes tightly, restricting certain proteins to the apical membrane?

A

Occludin

44
Q

What type of cell fusion is created by the ‘zonula occludens’?

A

Tight junctions by the protein ‘occludin’

45
Q

What type of epithelial cell line the villi of the small intestine?

A

Simple columnar epithelial cells

46
Q

What types of cells line the stomach, gastric glands, small intestine and colon?

A

Simple columnar epithelial cells

47
Q

What are the 3 main functions of a simple columnar epithelial cell?

A

1) Lubrication 2) Absorption 3) Secretion

48
Q

What is meant when an epithelium is described as ‘simple’?

A

Every cell makes contact with the basement membrane

49
Q

Describe the epithelial cells which line the upper respiratory tract:

A

Pseudostratified ciliated columnar epithelial cells

50
Q

How quick do the motile cilia present in the upper respiratory tract beat?

A

12 beats/sec

51
Q

Define epididymis:

A

A highly convoluted duct behind the testis, along which sperm passes to the vas deferens

52
Q

What is the ‘vas deferens’?

A

Duct which transports sperm from the testicle to the urethra

53
Q

Approximately how long is the epididymis?

A

~4-6m long

54
Q

What type of epithelial cells line the epididymis?

A

Pseudostratified epithelium, which contain stereocilia

55
Q

What is the function of the principal cells of the epididymus epithelium?

A

Absorb fluid Secrete substances to promote sperm maturation Phagocytose degenerate sperm

56
Q

How would you describe a stratified epithelium in which the cells have a different shape at the top, to the cells at the bottom?

A

The description always applies to the outermost layer of the epithelia.

57
Q

What type of epithelial cells line the vagina?

A

Non-keratinised stratified squamous epithelial cells

58
Q

What is present in the vagina to maintain the suitably low pH?

A

Lactobacilli, which produce lactic acid

59
Q

Why does the oesophagus have a stratified epithelium?

A

For lubrication and protection against abrasion

60
Q

Define epiglottis:

A

A flap of cartilage behind the root of the tongue, which is depressed during swallowing to cover the trachea.

61
Q

Describe the epithelium which lines the oesophagus side of the epiglottis:

A

Stratified squamous non-keratinised epithelium

62
Q

Describe the epithelium which lines the trachea side of the epiglottis:

A

Pseudostratified epithelium

63
Q

What is the name of the outer surface of the eye?

A

Cornea of the eye

64
Q

Which embryonic germ layer creates the cornea of the eye?

A

Ectoderm

65
Q

What is situated directly behind the cornea of the eye?

A

Anterior chamber

66
Q

What type of epithelial cells line the outer surface of the cornea (of the eye)?

A

Non- keratinised stratified squamous epithelial cells

67
Q

Name 7 locations which have non-keratinised stratified squamous epithelial cells:

A

1) Oral cavity 2) Oesophagus 3) Larynx 4) Vagina 5) Outer surface of cornea 6) Part of anal canal 7) Inner surface of eyelid

68
Q

What are the 2 main functions of a non-keratinised stratified squamous epithelium?

A

1) Prevent water loss but stay moist 2) Protect against abrasion

69
Q

What is meant by a ‘keratinised stratified epithelium’?

A

An epithelium whose outer layer is made up of dead cells with no nuclei.

70
Q

Where on the body can you find a thicker layer of dead keratinised epidermal cells?

A

Palms and soles of feet.

71
Q

What are the 4 main functions of a keratinised stratified squamous epithelium?

A

1) Protect against abrasion and/or physical trauma
2) Prevent water loss
3) Prevents ingress of microbes
4) Shields against UV light damage

72
Q

What is meant by a ‘transitional epithelium’?

A

An epithelium in which the cells vary in shape, from cubodal/columnar/squamous.

73
Q

Why would it benefit a tissue to have a transitional epithelium?

A

If the tissue must often stretch and relax, a transitional epithelium allows the tissue to be covered and protected at all times.

74
Q

What type of epithelium is present lining the ureter?

A

Transitional epithelia

75
Q

What type of epithelia is present lining the bladder?

A

Transitional epithelia

76
Q

What are the 2 main functions of a transitional epithelium?

A

1) Distensibility
2) Protection against toxic chemicals

77
Q

Why do different epithelia have different rates of renewal?

A

It depends on the location and function of the epithelia.

78
Q

What is the average turnover time for a skin epithelial cell? (from cell division to death)

A

~ 28 days

79
Q

What is the average turnover time for an epithelial cell present in the base of the crypts of the small intestine?

A

~ 4-6 days

80
Q

What is the main difference between microvilli and stereocilia?

A

Stereocilia are much longer than microvilli

81
Q

Where are stereocilia found in the body, and what is their (presumed) function?

A

On the epithelium lining the epididymis, thought to increase surface area.

82
Q

What are the 3 junctional complexes that a cell membrane can form, for lateral adhesion to other cells?

A

1) Desmosomes
2) zonulae occulentes
3) zonulae adherentes

83
Q

What can the cell membrane form to allow lateral cell-to-cell communication?

A

Gap junctions

84
Q

What does the basal cell membrane form to allow adhesion to the basement membrane?

A

Hemidesmosomes