Chap 1 Part 2 Flashcards Preview

Organ Histo > Chap 1 Part 2 > Flashcards

Flashcards in Chap 1 Part 2 Deck (40)
Loading flashcards...
1
Q

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

A

stratified epithelium

2
Q

What kind of function is shared by all stratified epithelium>?

A

protection

3
Q

Stratified Squamous epithelium have multiple layers of cells that tend to flatten out from basal layer to superficial layer. Where can this type of epithelium be found?

A

esophagus, oral cavity, tongue and vagina

4
Q

Although stratified squamous epithelium protects against abrasion, is protection is limited. Why? What are its limitations?

A

limited thickness; no protection from drying

5
Q

What is the function of Keratinized Stratified Squamous epithelium?

A

Protection in a dry environment

6
Q

What are the layers in epithelium of skin?

A

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum (Boys Seldom Get Lucky Consistently)

7
Q

Which layer of the keratized stratified squamous is composed of 1-2 layers of keratinocytes which are mitotic and closest to the dermis?

A

stratum basale (germinativum)

8
Q

Which layer of the keratinized stratified squamous is composed of multiple layers of “spiny shaped” keratinocytes? Thickness of this layer can vary.

A

Stratum Spinosum

9
Q

Which layer of the keratinized stratified squamous can be described as the uppermost 2-5 layers of flattened living keratinocytes where exocytosis of lipid-filled lamellar granules will occur?

A

stratum granulosum

10
Q

Which layer of the keratinized stratified squamous is not easy to see, present only in thick skin, and is a thin layer of recently dead or dying keratinocytes?

A

stratum lucidum (nucleus and organelles are not present)

11
Q

Which layer of the keratinized stratified squamous is composed of dead cells, karatin, and lipids? It also has 3 distinct functions.

A

stratum corneum

12
Q

What are the 3 functions of the stratum corneum?

A

prevents water loss, barrier to microbes, and protects against abrasion

13
Q

T/F: thickness varies in the stratum corneum and stratum spinosum.

A

True

14
Q

What is the the Malpighian layer?

A

stratum basale and stratum spinosum; a way of grouping layers together where cell division can occur

15
Q

How do epidermal pegs (rete ridges) and dermal papillae contribute to the strength of epithelium?

A

increase surface area for attachment of the epithelium to the CT below

16
Q

How long do epithelial cells live?

A

about 28 days

17
Q

Melanocytes do what and are found where?

A

protect against UV radiation; stratum basale

18
Q

What occurs with increased UV light exposure (with regard to melanocytes)?

A

skin color greatly influenced; melanocytes increase, increasing melanin

19
Q

T/F: melanocytes are about equal in all humans.

A

True

20
Q

Which type of cell recognizes external foreign antigens, is an epidermal dendritic cell, a resident APC, and is found in the stratum spinosum?

A

Langerhans Cells

21
Q

Which type of cell provides touch receptors, is associated with free nerve endings (very numerous in areas of high sensitivity) and is found in the stratum basale layer?

A

Merkel cells (fingertips and hair follicles)

22
Q

T/F: Melanocyte numbers decrease with repeated UV exposure.

A

False; this is true of Langerhans cells, melanocyte numbers increase

23
Q

What are the 5 types of stratified epithelium?

A

stratified squamous, keratinized stratified squamous, stratified cuboidal, stratified columnar, and transitional

24
Q

Which types of stratified epithelium function in protection?

A

all of them

25
Q

Where can you find stratified cuboidal? how many layers?

A

larger in ducts in sweat glands and salivary glands; 2 layers (basal layer is flattened and superficial is cuboid

26
Q

Wher can stratified columnar be found?

A

large ducts in pancreas, parts of male urethra and conjunctiva of the eye

27
Q

T/F: stratified columnar epithelium is very rare, and consists of two layers. The basal layer is flattened and the superficial is columnar in shape.

A

True

28
Q

Other than protection, what function does stratified columnar perform?

A

provides a transition between epithelial types

29
Q

What/where is transitional epithelium?

A

Urinary epithelium or urothelium; found in most of urinary tract

30
Q

Other than protection, what function is transitional epithelium specialized to do?

A

stretch

31
Q

What part of transitional epithelium is thin and fenestrated? which part is large and rounded? And which part is well developed?

A

basement membrane, superficial cells, and zonula occludens/tight junctions (respectively)

32
Q

Why is it important that transitional epithelium has a well-developed zonula occludens?

A

prevents wastes (urine) from seeping out; needed because of fenestrated basement membrane

33
Q

T/F: when transitional epithelium is stretched, distance of diffusion is increased.

A

False; the distance of diffusion is decreased therefore more oxygen can actually get into the cells

34
Q

Where do cells accumulate during psoriasis vulgaris (patchy skin lesions)?

A

in stratum corneum

35
Q

T/F: Freckles are an increase in melanin and melanocyte numbers.

A

False; they are an increase in melanin without an increase in melanocyte numbers

36
Q

What are patches which lack melanocytes called?

A

vitiligo

37
Q

What is the term for discolorization due to proliferation of melanocytes?

A

moles

38
Q

What is occuring when melanocytes become mitotically active and invade dermis? This is very invasive and metastic requiring surgery/chemotherapy.

A

malignant melanoma

39
Q

What condition occurs when melanocytes fail to produce melanin?

A

albinism

40
Q

What enzyme is missing from melanocytes in the most common form of albinism?

A

tyrosinase (a catalyst in the conversion of tyrosine to melanin)