Brainscape's Knowledge GenomeTM

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


See full index

Biology > The Skin(Complete) > Flashcards

The Skin(Complete) Flashcards

1
Q

What are the two layers of the skin called?

A

The epidermis.

The dermis.

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

Describe the structure and role of the Malpighian layer.

A

Cells are formed by mitosis.
They are hardened by waterproof protein keratin to replace dead cells in the outer cornified layer.
Cells produce the pigment melanin

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

Where is the protein keratin found?

A

The skin.
The hair.
The nails.

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

What is the role of melanin?

A

To protect against UV radiation.

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

Where is melanin found?

A

In the iris of the eye.
In the skin.
In hair.

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

What is melanoma?

A

When the cells that produce melanin become cancerous.

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

Describe the granular layer.

A

Cells are larger and keratinized as they migrate to the outer cornified layer.

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

Why are cells dead in the cornified layer?

A

As no blood supply and cells are coated with too much keratin.

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

Describe the cornified layer.

A

The outer layer of the skin with dead cells which is constantly shedding- the epidermis is replaced every 30 days.

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

What are the main roles of the outer cornified layer?

A

Cells have keratin with a natural waterproof layer which prevents natural moisture from leaving the skin keeping it hydrated.
It acts as a barrier against all pathogens and protects against pressure changes.

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

Describe the structure of the dermis.

A

Consists of live connective tissue with elastic and collagen fibres.

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

What is inside of the dermis?

A

Receptors, sweat glands, hair follicles, arterioles and sebaceous glands are all embedded into the dermis.

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

What is the role of the receptors?

A

The touch and temperature receptors detect a stimulus and generate impulses as a result.

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

What is the role of sweat glands?

A

Sweat glands produce the excretory fluid sweat which is carried to the surface of the skin by sweat ducts. Sweat is evaporated to cool down the body.
Has a big role in thermoregulation.

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

What is the role of sebaceous glands?

A

Sebaceous glands are connected to the side of the hair follicle.
They secrete sebum which is an oil which creates a moisturising layer, preventing the skin from cracking.

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

Where are hair follicles formed?

A

In the infoldings of the Malpighian layer.

17
Q

What is hair?

A

A solid cylinder made of dead cells and keratin.
The root of the hair is under the skin surface.
The shaft of the hair is above the skin surface.
Hair erector muscles control the movement of hair and therefore contract to allow hair to stand upright-thermoregulation.

18
Q

Where is adipose tissue located?

A

Under the dermis.

19
Q

How is adipose tissue formed?

A

Subcutaneous tissue and fat cells.

20
Q

What are the roles of adipose tissue?

A

To insulate the body.

To act as a food store.

21
Q

What are the main functions of the skin?

A

Formation of vitamin D in the presence of UV radiation.
Acts as a sense organ.
Insulates and acts as a food store by means of subcutaneous fat.
Protection.
Excretory role.
Thermoregulation.

22
Q

Describe the role of the skin in the formation of vitamin D.

A

The skin produces vitamin D which is essential for the absorption of calcium.
Lack of this vitamin would result in rickets causing the bones to become soft and legs would become bowed.

23
Q

Describe the role of the skin in acting as a sense organ

A

The skin contains receptors on its surface which detect stimuli such as heat, cold and touch and generate impulses as a result.

24
Q

Describe the role of the skin in insulating the body and acting as a food store.

A

Adipose tissue contains fat cells which insulate the body and act as a food store.

25
Q

Describe the role of the skin in protection.

A

The outer cornified layer acts as a barrier against all pathogens.
It is constantly flaking away taking pathogens with it.
Sebaceous glands secrete sebum which is an oil that coats the skin and hair and moisturises the skin preventing cracking and the entry of pathogens.
The skin excretes sweat which contains the enzyme lysozyme which causes lysis in pathogens.
Melanin in the skin protects from UV radiation.
The hair acts as a barrier against many insect pests.

26
Q

Describe the role of the skin in its excretory role.

A

Sweat is an excretory fluid produced by sweat glands and is taken to the surface of the skin by sweat ducts.
Sweat excretes water, salts, urea and lactic acid.

27
Q

What is the body’s response to a rise in temperature?

A

Increased sweating- sweat evaporates using heat from the body which lowers body temperature.
VAsodilation- the arterioles widen which increases blood flow to the skin’s surface which increases heat loss.
The hairs lay flat to not trap warm air.

28
Q

What is the body’s response to a loss in temperature?

A

Vasoconstriction- arterioles narrow to decrease blood flow towards the skin’s surface and reduce heat loss.
Piloerection- hairs stand upright to increase warm air trapped close to the skin’s surface.

29
Q

Describe briefly the hormonal and nervous responses that occur when the internal body temperature drops.

A

Nervous- Shivering generates heat as muscles contract

Hormonal- Excess levels of thyroxine increase aerobic respiration which releases heat.

30
Q

State two ways in which the body is insulated against the loss of heat.

A

Subcutaneous fat.

Hair.

31
Q

Suggest a biological reasoning for the following:

A person’s fingers may turn white when exposed to low temperatures for a period of time.

A

Arterioles constrict.

Lessens blood flow to the fingers to reduce heat loss.

32
Q

What is the importance of thermoregulation?

A

To maintain the body temperature of 37.8C.
To help maintain a high rate of metabolism.
Prevents enzyme denaturation.

33
Q

What is an endoderm?

A

Their body temperature is independent of the temperature of the environment.
Can vary their metabolic rates.

34
Q

Give 2 examples of endoderms.

A

Mammals.

Birds.

35
Q

What is an ectoderm?

A

Their body temperature varies with the temperature of the environment.
Cannot vary their metabolic rates.

36
Q

Give 2 examples of ectoderms.

A

Reptiles.

Amphibians.

37
Q

How do ectoderms rely on behaviour to regulate body temperature?

A

They lie broadside to the sun or source of heat or move to hot areas to raise their body temperature.
Move to cold areas to lower their body temperature.

38
Q

What is the source of heat that allows the body to maintain a constant internal temperature?

A

Respiration of glucose in muscle and liver cells.

39
Q

What is the skin?

A

A self-replacing, self-healing barrier to invading pathogens.
It is our organ of touch.

Biology (36 decks)

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