Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PA10315 COPY > Structure of the skin > Flashcards

Structure of the skin Flashcards

1
Q

What is the integumentary system?

A

It’s made up of the skin and its accessory structures, such as hair, nails, glands and sensory receptors.

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

What is the surface area of adult human skin?

A

1.8-2 metre squared.

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

What is the range for the thickness of adult skin?

A

0.5 - 4.5mm.

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

What is the principle function of the skin?

A

To keep water inside of us as the external environment is generally dry.

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

What are the two main parts of the skin?

A

The epidermis (the top part - 1/10mm thick) and the bottom part, the dermis (1mm thick).

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

Where is thick skin found?

A

On the palms, tips of fingers, digits and soles of feet.

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

What are the differences between thick skin and thin skin?

A

Thin skin has hair follicles coming through that are based deep in the dermis. Thin skin is around 1/10mm whereas thick skin can be several mm thick.

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

What are the type of cells that make up the epidermis?

A

Keratinised, stratified squamous epithelium.

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

What is the bottom most layer of the skin and what is its function?

A

The stratum basale, it is a single layer of columnar keratinocytes. It is the site of production of new keratinocytes.

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

What is the second most bottom layer of the skin?

A

The stratum spinosum which is composed of multiple rows of closely packed keratinocytes

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

What is the third most bottom layer of the skin and its function?

A

The stratum granulosum which is multiple rows of flattened keratinocytes that contain keratohyalin granules and lamellar bodies. These form a hydrophobic, impermeable barrier on release.

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

What is the second most top layer of the skin?

A

The stratum lucidium which is multiple rows of clear, flat, dead, keratin-rich keratinocytes. It is only present in thick skin.

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

What is the top layer of the skin?

A

The stratum corneum which is made of multiple rows of dead, flat, enucleate keratinocytes that are made up of cross-linked keratin fibres.

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

What happens to keratinocytes as they get closer and closer to the surface of the skin?

A

They get further and further away from the “food supply” (blood vessels) and they will eventually begin to die. This is controlled apoptosis.

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

What is the purpose of the lipid-rich lamellar bodies in the stratum granulosum?

A

It provides an oily layer to prevent water evaporating out of the body.

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

What are desmosomes and where are they found?

A

A structure that links two adjacent cells. They are found in the stratum spinosum.

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

How do certain skin diseases arise?

A

There is an imbalance between the formation and death of skin cells. The barrier gets weaker as the turnover is faster than production, for example in psoriasis.

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

What are keratins?

A

A family of cytoskeletal filament-forming proteins that make up 25-30% of the total protein in the epidermis.

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

What is the purpose of keratins in the skin?

A

They form branching, rope-like structures in the cell cytoplasm that associate with adjacent cells. They maintain the structural integrity of the epidermis.

20
Q

What is unique about the lipid matrix of the stratum corneum?

A

There are no phospholipids and is mostly composed of ceramides, free fatty acids and cholesterol.

21
Q

What happens to desmosomes when the skin cells die?

A

They get broken down by enzymes.

22
Q

What are Langerhan cells?

A

They are cells that communicate with the immune system and provide a warning system for the skin if harmful substances come into contact, such as poison ivy.

23
Q

What are Merkel cells?

A

Sensory cells that provide a somatic connection to nerve endings such as when something hot is touched.

24
Q

What are Melanocytes?

A

Cells that make melanin and package it into melanosomes.

25
Q

What is the function of melanin?

A

To provide protection against the sun.

26
Q

How are melanosomes transferred to keratinocytes from melanocytes?

A

Epithelial cells phagocytize the tips of the melanocyte and enter the keratinocytes.

27
Q

What does peri-nuclear mean, in terms of melanosomes?

A

The melanosomes surround the nucleus of the keratinocytes to protect them from direct radiation.

28
Q

What are the three types of melanin?

A

Eumelanin, pheomelanin and neuromelanin.

29
Q

What is skin colour mostly dependent on?

A

The amounts of eumelanin and pheomelanin.

30
Q

What are the two regions of the dermis and what proportions are they present in?

A

The papillary (20%) near the top and the reticular (80%) near the bottom.

31
Q

What separates the epidermis and the dermis?

A

The basement membrane (basal lamina).

32
Q

What is the function of the basement membrane?

A

It is a bridging structure and regulates proliferation in the stratum basale and the movement of cells between the dermis and epidermis.

33
Q

What is the purpose of the basement membrane being convoluted?

A

There are more contact points which provides a mechanical benefit.

34
Q

What is the papillary made up of?

A

Elastic fibres and nerve endings - it is a connective tissue.

35
Q

What is the reticular made up of?

A

Dense, connective tissue that is made up of randomly orientated collagen fibres, elastin, proteoglycans and glycosaminoglycans.

36
Q

What are the hairs in the skin composed of?

A

Lots of dead, keratinised epithelium cells.

37
Q

What is the function of the sebaceous gland?

A

It secretes sebum which is a mixture of oily lipids that lubricate the hair shaft.

38
Q

What is horripilation?

A

When hairs stand on end due to the muscle attached to the hair.

39
Q

What are the four stages of hair growth?

A

Anagen, catagen, telogen and exogen.

40
Q

What are glands?

A

Specialised secretory structures formed by epithelial cells.

41
Q

What are the two categories of glands?

A

Endocrine (ductless) and exocrine (with ducts).

42
Q

What are the three modes of secretion from exocrine glands?

A

Merocrine, apocrine and holocrine.

43
Q

What are sebaceous glands?

A

They produce lipid rich sebum.

44
Q

What is the difference between apocrine and eccrine sweat glands?

A

Apocrine glands have limited distribution and are only active from puberty. They are more viscous than eccrine. Eccrine glands are widely distributed and are active shortly after birth.

45
Q

What are the three types of skin sensory receptors?

A

Mechanoreceptors, thermoreceptors and nociceptors.

PA10315 COPY (48 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions