Chapter One - Epithelium Flashcards Preview

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Flashcards in Chapter One - Epithelium Deck (123)
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0
Q

What are the three general functions of epithelium?

A

Absorption, secretion, and providing a barrier

1
Q

What are the four basic types of tissue?

A

Epithelial, muscle, nervous, and connective

2
Q

Which general function of epithelium is a function of ALL epithelium?

A

Providing a barrier

3
Q

What produces the basal lamina of the basement membrane?

A

Epithelium

4
Q

What are the three specialized functions of epithelium?

A

Transfer molecules across epithelium, prevent transfer of materials (aka selective permeability), sensory function

5
Q

What produces the reticular lamina in the basement membrane?

A

Fibroblasts in connective tissue

6
Q

What are the two parts of the basement membrane of epithelium?

A

Basal lamina and reticular lamina

7
Q

What makes up a partial basement membrane of epithelium?

A

Basal lamina ONLY

8
Q

What are the functions of the basement membrane of epithelium?

A

Providing a surface for epithelial cell attachment, molecular filter (very limited), limits stretch, and directs migration of cells

9
Q

Are epithelial cells vascular or avascular?

A

Avascular

10
Q

By what process do epithelial cells obtain nutrition?

A

Diffusion

11
Q

What are the functions of connective tissue?

A

Provides nutrition (and oxygen), source of defensive cells

12
Q

Which type of cell junction involves the sharing of intrinsic membrane proteins between adjacent cells?

A

Zonula occludens

13
Q

What is the other name for zonula occludens?

A

Tight junction

14
Q

What are the functions of zonula occludens (tight junctions)?

A

Provides strong attachment, prevents the passage of materials between cells

15
Q

Zonula adherens consist of what?

A

Cadherins (linkage proteins) and marginal bands (microfilaments)

16
Q

What part of the zonula adherens are located between cells?

A

Cadherins

17
Q

What is the other name for zonula adherens?

A

Adhesion belt

18
Q

What part of the zonula adherens attach the cytoskeleton to the cell membrane?

A

Marginal bands

19
Q

What are the functions of the zonula adherens?

A

Strong attachment and provide cell structural stability

20
Q

What is another name for macula adherens?

A

Desmosome

21
Q

What is the function of macula adherens?

A

Provides strong attachment

22
Q

What are the three parts of the macula adherens?

A

Transmembrane proteins, protein plaque, and tonofilaments

23
Q

Which type of cell junction is arranged in a cylinder with six connexins (proteins)?

A

Gap junctions

24
Q

What are the two functions of gap junctions?

A

Strong attachment, transport materials between cells

25
Q

What makes up the junctional complex (in order)?

A

Zonula occludens, zonula adherens, macula adherens

26
Q

What junctions hold the epithelium to the basement membrane and the connective tissue below?

A

Hemidesmosomes and focal point contacts

27
Q

What is the function of hemidesmosomes?

A

Helps connect epithelial cells to the basal lamina (essentially half a desmosome)

28
Q

What is bullous pemphigoid?

A

An autoimmune skin disease causing large blistering lesions that burst but do heal

29
Q

What is pemphigus vulgaris?

A

An autoimmune skin disease causing skin blistering that do not heal easily; excessive bleeding is likely & can be fatal

30
Q

What is cholera?

A

Acute bacterial infection of the small intestines

31
Q

What is the cause of bullous pemphigoid?

A

Antibodies bind to some proteins in hemidesmosomes

32
Q

What is the cause of pemphigus vulgaris?

A

Antibodies bind to some parts of desmosomes

33
Q

What is the cause of cholera?

A

Toxins disrupt proteins in the zonula occludens which permits the loss of water and electrolytes from the connective tissue below the epithelium

34
Q

What is the general name for the type of epithelium that is one cell thick?

A

Simple epithelium

35
Q

What type of simple epithelium is a single layer of flattened cells?

A

Simple squamous

36
Q

What type of epithelium is found in the lungs, parietal layer of the Bowman’s capsule in the kidney, and the serosa on the outside of organs?

A

Simple squamous

37
Q

What are the functions of simple squamous epithelium?

A

Living filter, provide a barrier

38
Q

What type of simple epithelium is located in exocrine ducts, thyroid follicular cells, and the proximal and distal convoluted kidney tubules?

A

Simple cuboidal

39
Q

What are the functions of simple cuboidal epithelium?

A

Absorption, secretion, provide a barrier

40
Q

What type of simple epithelium is one layer of cube shaped cells?

A

Simple cuboidal

41
Q

What type of simple epithelium represents a single layer of rectangular shaped cells that appear vertical?

A

Simple columnar

42
Q

What type of epithelium is located in the stomach, small intestines, gallbladder, colon, and larger exocrine ducts?

A

Simple columnar

43
Q

What are the functions of simple columnar epithelium?

A

Absorption, secretion, provide a barrier

44
Q

What type of simple epithelium is also known as respiratory epithelium?

A

Ciliated pseudostratified columnar epithelium

45
Q

What type of simple epithelium is located in the trachea, respiratory region of nasal cavity, and the bronchi?

A

Ciliated pseudostratified columnar epithelium

46
Q

What is the function of goblet cells?

A

Produce and secrete mucus

47
Q

Ciliated pseudostratified columnar epithelium is made up of what three types of cells?

A

Goblet cells, ciliated columnar cells, and basal cells

48
Q

What is the function of the ciliated columnar cells found in ciliated pseudostratified columnar epithelium?

A

To move mucus over the membrane

49
Q

What type of cell in respiratory epithelium does not reach the surface?

A

Basal cells

50
Q

What is the function of the basal cells of respiratory epithelium?

A

To be the stem cell of that type of epithelium (proliferation and differentiation)

51
Q

What are the finger like projections at the apical surface on some epithelial cells?

A

Microvilli (brush border or striated border)

52
Q

What is the function of microvilli?

A

To increase surface area so as to increase absorption

53
Q

What are good example locations of microvilli?

A

Kidney tubule cells and small intestines

54
Q

What are extremely long microvilli?

A

Stereocilia

55
Q

Where can stereocilia be found?

A

Epididymis, cochlear hair cells

56
Q

What is the function of stereocilia?

A

To increase surface area

57
Q

Are stereocilia considerably motile?

A

No, less motile; they are actually quite rigid with actin core (not related to true cilia)

58
Q

What is the function of cilia?

A

To move something over a surface

59
Q

What are the apical hair-like extensions of the cytoplasm that function in movement?

A

Cilia

60
Q

What are good examples of ciliary locations?

A

Trachea and fallopian tube

61
Q

What organelle is largely seen in cilia?

A

Mitochondria

62
Q

What anchors cilia?

A

Basal bodies

63
Q

What is the result of basal bodies in cilia blocking the free surface?

A

No absorption or secretion

64
Q

What is the surface layer of glycoproteins and carbohydrates that covers some epithelium?

A

Glycocalyx

65
Q

What produces the glycocalyx?

A

Epithelial cells

66
Q

What are the functions of the glycocalyx?

A

Protection and cell recognition

67
Q

What are other possible functions of the glycocalyx?

A

Cell adhesion and holds enzymes

68
Q

What are example locations of the glycocalyx?

A

Stomach and small intestines

69
Q

What type of epithelium is two or more cell layers thick?

A

Stratified epithelium

70
Q

What is the general function of all stratified epithelium?

A

Protection

71
Q

Types of stratified epithelium are named after what cells?

A

Superficial layer of cells

72
Q

What type of stratified epithelium has multiple layers of cells that seem to flatten out from the basal layer to the superficial layer & the superficial layer of cells are flat and alive?

A

Stratified squamous epithelium

73
Q

What type of epithelium is found in the esophagus, oral cavity, tongue, and vagina?

A

Stratified squamous epithelium

74
Q

What is the general function of stratified squamous epithelium?

A

Protection from abrasion/friction

75
Q

What is the type of epithelium of the skin?

A

Keratinized stratified squamous epithelium

76
Q

What are some limitations of stratified squamous epithelium?

A

No protection from drying and limited thickness leading to limited protection

77
Q

What is the function of keratinized stratified squamous epithelium?

A

Protection in a dry environment

78
Q

What are the layers of the skin?

A

Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

79
Q

Which layer of the skin is made of dead cells, keratin, and lipids?

A

Stratum corneum

80
Q

What are the three general functions of the stratum corneum?

A

Prevents water loss, provides a barrier to microbes, protects against abrasion

81
Q

Which two layers of the skin are layers where cell division can occur?

A

Stratum basale and stratum spinosum

82
Q

Which layer of the skin is closest to the dermis and is made up of 1-2 layers of mitotic keratinocytes?

A

Stratum basale

83
Q

Where are melanocytes found?

A

Stratum basale

84
Q

What is the general function of melanocytes?

A

Protect from UV radiation

85
Q

What cells determines skin color?

A

Melanocytes

86
Q

Which type of melanin is known to represent darker pigments?

A

Eumelanin

87
Q

Which type of melanin represents a reddish color?

A

Pheomelanin

88
Q

What three things influence skin color?

A

Environment, genetics, number of blood vessels in the dermis

89
Q

True or false: everyone has the same number of melanocytes.

A

True! The difference is the production of melanin of each melanocyte

90
Q

Where are Langerhans cells located?

A

Stratum spinosum

91
Q

What is the function of the Langerhans cells?

A

Recognize and process foreign antigens (APC)

92
Q

What effect does UV radiation have on Langerhans cells?

A

Reduction

93
Q

What type of epithelium can be found in the sweat and salivary glands?

A

Stratified cuboidal epithelium

94
Q

What effect does repeated UV exposure have on melanocytes?

A

Increased numbers

95
Q

What are the functions of stratified cuboidal epithelium?

A

To increase protection and provide a barrier

96
Q

What are the functions of stratified columnar epithelium?

A

Increase protection, provide a transition between epithelial types, provide a barrier

97
Q

What cells are known as the epithelial tactile cells?

A

Merkel cells

98
Q

Merkel cells are located in what layer of the skin?

A

Stratum basale

100
Q

What layer of the skin is associated with free nerve endings?

A

Stratum basale (due to Merkel cells)

101
Q

The function of taste buds and the retina of the eye are examples of what specialized function that can be possessed by epithelium?

A

Sensory

102
Q

What transmembrane protein of the cell membrane binds to structural connective tissue glycoproteins and also connects to cytoskeleton?

A

Integrin (focal point contacts)

103
Q

During the stem cell division of one basal cell of respiratory epithelium, what are the two daughter cell types?

A

One basal cell and one goblet cell/ciliated columnar cell (2 total)

104
Q

What covers the superficial cell layer of keratinized stratified squamous epithelium?

A

Nonliving layer of keratin

105
Q

What is another term for the stratum basale?

A

Stratum germinativum

106
Q

Which layer of the skin contains multiple layers of “spiny shaped” keratinocytes?

A

Stratum spinosum

107
Q

What do the keratinocytes found in the stratum spinosum produce?

A

Lipids and keratohyaline vacuoles

108
Q

In which layer of the skin does exocytosis of lipid-filled lamellar granules occur?

A

Stratum granulosum

109
Q

Which layer of the skin is only present in thick skin, is difficult to see, and does not contain nuclei or organelles?

A

Stratum lucidum

110
Q

What structures contribute strength to keratinized stratified squamous epithelium by increasing surface area of attachment of the epithelium to the connective tissue below?

A

Epidermal pegs (rete ridges)

111
Q

What is the relative half life of skin cells?

A

28 days

112
Q

What type of epithelium is likely to be seen in the large ducts in the pancreas, parts of the male urethra, and the conjunctiva of the eye?

A

Stratified columnar

113
Q

What is the appearance of the basal layer of stratified columnar epithelium?

A

Flattened to cuboidal in shape

114
Q

What is the frequency of stratified columnar epithelium in the body?

A

Rare

115
Q

What is another name for transitional epithelium?

A

Urinary epithelium or urothelium

116
Q

What is the microscopic appearance of the basement membrane and nuclei of transitional (urinary) epithelium?

A

Straight basement membrane and round nuclei

117
Q

What type of epithelium makes up most of the urinary tract?

A

Transitional epithelium

118
Q

What are the functions of transitional (urinary) epithelium?

A

Provide protection, to stretch, act as a barrier

119
Q

What is the basement membrane structure of transitional epithelium?

A

Thin and fenestrated

120
Q

What type of cell junction is well-developed with transitional (urinary) epithelium?

A

Zonula occludens (tight junctions)

121
Q

Why is it important for transitional (urinary) epithelium to have well-developed tight junctions?

A

Extra support is needed due to the fenestrated basement membrane, prevents wastes/urine from seeping between epithelial cells

122
Q

What is the unusual superficial cell feature of transitional (urinary) epithelium?

A

Presence of some bi-nucleated superficial cells

123
Q

Why do the cells of transitional (urinary) epithelium obtain more oxygen?

A

Due to fenestrated basement membrane and decreased diffusion distance when stretched