Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Skin > Flashcards

Skin Flashcards

1
Q

What system does the skin belong to

A

The integumentary systems of our body

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

Largest organ of our body

A

Skin

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

The skin is what percent of an adult human body’s weight

A

15 percent

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

Is the skin permeable

A

It is an almost impermeable barrier

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

What is the skin

A

The outermost covering of the body. It’s stretched out all over in the form of a layer. Many structures and glands are derived from it

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

Skin aka

A

Integument

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

Functions of the skin

A

1) Protection of the underlying tissues from mechanical shocks, preventing loss of water by evaporation by holding body fluids inside, preventing harmful substances or germs from entering body, and protecting against excess ultraviolet light.

2) Regulates temperature by preventing loss of heat in cold weather and facilitating loss of heat in warm weather.

3)Stores reserve food in the form of a layer of fat contained in special cells.

4) Assists in the process of excretion (thru sweating) of water, salts and very small content of urea.

5) Serves as a sense organ for touch pain pressure heat etc.

6) The skin can synthesise vitamin d upon expose to sunshine.

7) On prolonged expose to water the skin of fingers wrinkles/pickers up giving better grip in slippery and wet environments.

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

How does the skin protect us

A

Protection of the underlying tissues from mechanical shocks

Preventing loss of water by evaporation by holding body fluids inside

Preventing harmful substances or germs from entering body

Protecting against excess ultraviolet light

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

Why is skin not excretory organ

A

As sweating from the skin occurs mainly for temperature regulation
It is an accessory function

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

Too much sunshine causes

A

Tanning
Other ill effects even skin cancers

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

Principal two divisions of skin

A

Skin proper
Derivatives of skin

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

Skin proper is composed of which 2 layers

A

Outer epidermis
Inner dermis

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

Characteristics of epidermis

A

It is the outer thinner part of the skin.
It is formed of stratified epithelium piled layer after layer.
At places, it becomes thick and hard.
It is fully devoid of blood vessels.

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

Where is the epidermis thick and hard

A

Palms, soles and heels (specially heels)

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

3 regions of epidermis (depth wise)

A
  1. Stratum corneum
  2. Granular layer
  3. Stratum malpighi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Stratum corneum aka

A

Cornified layer

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

Stratum malpighi aka

A

Malpighian layer, germinative layer

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

Stratum corneum dead / living

A

Dead

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

Stratum corneum characteristics

A

Outermost layer consists of several piled up layers of flattened dead cells.

These cells are made of keratin a fibrous structural protein.

The cells are continually worn away/shed and are replaced from beneath by the cells arising from the deeper malpighian layer.
This layer is tough.

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

Stratum corneum functions/offers resistance to what?

A

Offers resistance to
Mechanical damage
Bacterial infection
Loss of water by evaporation

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

Keratin is what and where is it found

A

Found in the cells of stratum corneum and nails, hairs horns hooves and silk.
It’s a fibrous structural protein.

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

The granular layer characteristics

A

Very thin middle layer consisting of two or three sub layers of flattened cells
Gradually it gives way to the outermost cornified layer.

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

Stratum malpighi

A

Innermost region of epidermis. Cells actively divide to produce new cells which press and shift outward to replace the worn out cells of outermost cornified layer.

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

What is melanin

A

It is a pigment which causes colouration of the skin.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Where is melanin contained
Malpighian layer
26
How does skin pigment help us
It acts as an umbrella to protect inner parts of body from the harmful effects of the ultra violet rays of sunlight which can cause skin cancer.
27
What are the two abnormal conditions of skin pigment
Leukoderma Albinism
28
Leukoderma aka
Vitiligo
29
Define leukoderma
Skin pigmentation (melanin) is lost from smaller or larger patches at different regions of the body
30
Albinism
Complete loss of pigmentation of the skin all over the body including hair, eyebrows and even the iris. The skin of affected individuals appears pinkish because of the underlying blood capillaries. It is a recessive trait caused due to inheritance.
31
What is the dermis
It is the inner thick layer of connective tissue made of elastic fibres. It's tough and flexible.
32
What is the dermis
It is the inner thick layer of connective tissue made of elastic fibres. It's tough and flexible.
33
What is the dermis
It is the inner thick layer of connective tissue made of elastic fibres. It's tough and flexible.
34
Where is the dermis v thick
Palms and soles
35
Where is the dermis v thin
Eyelids
36
What does the dermis contain
Blood vessels, nerve fibres, sensory organs, hair follicles, sweat glands
37
Leather is what layer of skin
Dermis
38
What are papillae
The outer region of the dermis which lies next to the epidermis is raised into numerous small processes called papillae which contain blood capillaries and nerve endings.
39
What do papillae contain
Nerve endings and blood capillaries
40
What are the nerve endings and sense organs in papillae associated with
Sensations of touch and pain.
41
What helps the blind to read the Braille characters
The sharp sense of touch in the finger tips
42
Sense receptors in deeper parts are concerned with sensations of
Pressure pain heat cold etc.
43
Fat is where
The layers beneath the dermis have many fat cells aka adipose tissue
44
Fat function
Serves as food reserve As a heat insulating layer As a shock absorber
45
______ fat
Subcutaneous
46
Special derivatives of human skin
Hair Nails Sebaceous glands Sweat glands Mammary glands
47
Three parts of hair
Hair shaft Hair root Hair bulb
48
Three parts of hair
Hair shaft Hair root Hair bulb
49
Hair shaft
It is the part which projects from the skin and may extend slightly above the surface of the epidermis.
50
A normal situations how does the hair shaft lie
Obliquely on the skin
51
Hair root is located where
It is embedded within the dermis
52
Hair bulb contains
A projection of the dermis called hair papilla with capillary blood supply
53
What is the hair follicle
It is a structure enclosing the hair root.
54
What is the hair follicle composed of
An epithelial and a connective tissue sheath
55
What is the hair follicle composed of
An epithelial and a connective tissue sheath
56
Function of hair bulb and hair follicle
Growth and elongation of hair
57
What is responsible for the growth and elongation of hair and how does it occur
Hair bulb and hair follicle Addition of cells at the base which soon die
58
What do hair follicles contain? What gives hair it's colour
Hair follicles contain pigment cells that produce melanin The colour of hair is due to varying quantities of melanin.
59
Why does have become grey silvery or even completely white
Due to decrease in melanin lroduction
60
What is goose flesh
During winter or during some emotions the hair is lifted and its called piloerection and the surface of the skin presents a some what contracted and wrinkled appearance.
61
Why does piloerection occur
Due to the erector muscle. The contraction of this muscle at one end pulls the hair to a somewhat vertical position and at the other end depresses the epidermis
62
Erector aka
Arrector
63
Erector muscle location
Runs obliquely between the hair follicle and the outer part of the dermis
64
What is the duration of scalp hair
2 to 5 years
65
What is the duration of scalp hair
2 to 5 years
66
Duration of eyebrow and eyelashes
3 - 5 months
67
How is hair from different parts of the body helpful
Forensic investigations Provides sensation of touch because nerve fibres extend to their bases Hairs along edges of eyelids (eyelashes) prevent entry of foreign substances and hair in nose prevents entry of dust particles entering nasal passage. Facial hair in human males like moustache and beard help in distinguishing male sex known as sexual dimorphism
68
What are nails
Hardened keratinous plate like structures which grow as dead cells from the nail root, which lies below the skin at the base
69
What do sebaceous glands open to
Usually a hair follicle Sometimes even directly to the outside
70
What do sebaceous glands give out and what’s it called and what’s its function
An oily secretion called sebum It makes hair and outer surface of skin oily and waterproof to keep the epidermis supple and to prevent loss of moisture by evaporation.
71
How are the sebaceous glands in shape
Branched
72
How does skin become in cold and dry weather? Why?
As there is a reduced secretion of oil from the sebaceous glands skin becomes rough and leaves a powdery surface when scratched
73
How does skin become in hot and humid weather and why
Extra oily due to increased secretion of sebum
74
In what weather skin becomes extra oily
Hot and humid
75
In what weather does skin become rough and leave powdery surface when scratched
Cold and dry
76
Three common problems related to sebaceous glands
Pimples Acne Black heads
77
How does sweat gland look
Each sweat gland is a simple coiled tube
78
What does sweat gland consist of
Deeper secretory part Excretory part which runs upwards to open on the surface
79
Outer openings of sweat glands
Sweat pores
80
Total number of sweat pores
2 million
81
Sweat pore
The outer openings of sweat glands
82
Who has more sweat pores
Human races belonging to hotter countries when compared to those belonging to cold ones
83
Function of secretory part of sweat gland
It absorbs fluid from the surrounding cells and blood capillaries of the dermis and passives it into the excretory sweat duct
84
Function of excretory sweat duct
After receiving fluid from secretory part of sweat gland it pours it out on the surface.
85
When does sweating occur
At all times
86
Minute quantities of sweating is called
Incipient or invisible perspiration
87
When is sweat in large quantities
During strenuous exercise or during hot and humid weather
88
Major function of sweating
To lose body heat by evaporation
89
Sweat consists of
About 99 percent water 0.2 to 0.5 percent salts (mainly sodium chloride) Traces of urea (0.8 percent)
90
Urea secreted by sweat is water percent of total urea secreted by body
1 percent
91
What is cold sweat? What emotions does sweating accompany (may)?
May be due to psychic influences such as fright and nervousness. Sweating may also accompany nausea and severe pain.
92
All mammals including humans are
Warm blooded or endothermal meaning the body heat is generated from inside.
93
Our body heat is more or less
Constant
94
Ectothermal
Cold blooded. Their body temperature fluctuates with the environmental temperature
95
Which animals hibernate and why
Ectothermal, their temperature fluctuates with environmental temperature. Thus they must somehow escape both conditions of too hot/too cold environment and thus they aestivate (summer sleep) or hibernate (winter sleep)
96
Aestivating animal
Frog
97
Aestivate
Summer sleep
98
Hibernate
Winter sleep
99
Ectothermal fancy
Poikilothermal
100
Endothermal fancy
Homeothermal
101
Human body temperature in mouth, rectum, arm pits
37 *C, 1 Celsius higher in rectum 1 Celsius lower in the arm pits
102
Our body may show variation in temperature by how much in what duration?
0.3 to 0.5 Celsius in course of 25 hours
103
Lowest (temp) in
Early morning
104
Highest (temp) in
Late afternoon
105
What does rise in body temperature above normal mean ? What about fall?
Fever and sickness, fall is dangerous.
106
What is optimum temperature range why is it essential
35 to 40 C for normal body activities esp for action of enzymes. Working of enzymes is slowed down with lowering of temperature whilst higher temperatures destroy enzymes altogether.
107
Sources of heat production
Chemical reactions - occurring in all body cells, especially liver by oxidation of glucose, generally produces heat Activity of muscles. Vigorous activity makes one warm on cold day, overheats on hot day. A small amt - ingestion of hot foods and beverages
108
Heat loss
Skin - 85 percent lost here by convection, conduction, radiation and evaporation of sweat Lungs - In warm air breathed out. Vaporisation of water from lungs. Urine and faeces - Eliminated at Body temp Foods - when cold food, water or cold beverages are taken into body
109
Principle heat regulation centre location
Hypothalamus, a portion of forebrain
110
Hypothalamus function
Acts like thermostat. When body tends to cool below normal temp it switches on/speeds up heat producing processes and when body tends to get over heated it accelerates cooling process, switches off the heat producing processes.
111
Vasoconstriction
When outside temperature is low, the blood vessels get narrowed. This reduces the blood supply to the skin. Thus, less heat is lost by convection conduction and radiation, and less is lost through vaporisation of sweat.
112
What physically occurs in a person during Vasoconstriction?
The person looks pale or bluish because of reduced blood supply to the skin. Heat production is increased by the increased metabolic rate and through increased muscular activity, which sometimes in the form of shivering.
113
Vasodilation
When there’s overproduction of heat within body blood supply to the skin is increased by the dilation of blood vessels in the skin. Thus, more heat is lost by radiation, convection and conduction, and by vaporisation of sweat, which is latent heat. Sweat is now produced in larger quantities due to the rich supply of blood to the skin.
114
Why do fans which do not cool? The air of the room? Have a cooling effect on our body?
Air movements over the body helps speed up, evaporation of sweat
115
Heatstroke
A condition in which sweat production is unable to keep base with its evaporation in very hot winds
116
Heatstroke results
Rise in body temperature, which is fever, which may sometimes be fatal
117
Precaution against heatstroke
Drinking a lot of water and taking a little more salt in summer
118
Why do we need Five kingdom classification
As there are millions of organisms starting from single celled microorganisms to large multicellular ones
119
How are organisms grouped to study their diversity?
Grouped according to their increasing similarities. Also from less to more complex.
120
What are the 7 categories
Kingdom Phylum Class Order Family Genus Species
121
Kingdom + Example
Largest division of related organisms Animalia
122
Phylum + Eg
Largest division in classification of plants and animals. Related classes and grouped in one phylum. Chordata.
123
Class + Eg
Related orders comprise a class. Vertebrate, Mammalia
124
Order + Eg
Related families comprise an order. Primates.
125
Family + Eg
A group of genera with certain common characteristics form a family. Hominidae
126
Genus + Eg
Similar species constitute a genus. Homo
127
Species + Eg
Group of organisms whose members can interbreed amongst themselves to produce fertile young ones. sapiens.

Biology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions