The Integumentary System (Skin)

Front 1

What are the other names for the skin?

Back 1

The skin has two other names:

1) The integument.

2? The subcutaneous layer.

Front 2

Describe the skin.

Back 2

The skin is the largest organ by weight. It contributes approximately 15-20%.

Front 3

How would one identify various body conditions related to the skin?

Back 3

Five skin related conditions can be identified as follows:

1) Injuries could be identified through bruising.

2) Vitamin deficiencies can be identified through scaliness.

3) Jaundice can be identified through yellow skin.

4) Viral diseases can be identified through rashes.

Front 4

What are the functions of skin?

Back 4

There are four basic functions of the skin and they are:

1) The ski functions to provide protection.

2) Sensory functions.

3) Thermoregulatory functions

4) Metabolic functions

Front 5

Describe the protection functions of the skin.

Back 5

The skin functions to protect the body from:

1) Ultraviolet light.

2) Thermal, mechanical and chemical stresses.

3) Dehydration.

4) Invasion by microorganisms.

Front 6

Describe the sensory functions of the skin.

Back 6

The skin has receptors that are able to sense touch, pain, pressure and temperature.

Front 7

Describe the thermoregulation function of the skin.

Back 7

The skin functions to regulate the body temperature making use of sweat glands, adipose tissue and hair.

Front 8

Describe the metabolic function of the skin.

Back 8

The adipose tissue found in the subcutaneous layer functions to produce vitamin D and triglycerides.

Front 9

How many layers make up the skin and what are they called?

Back 9

There are three layers that make up the skin and they are called:

1) Epidermis.

2) Dermis.

3) Hypodermis.

Front 10

Describe the epidermis.

Back 10

The epidermis is the most superficial layer of the skin and it is made up of stratified squamous epithelium and is lined with the protein keratin.

Front 11

What are the cells found in the epidermis called?

Back 11

The cells found in the epidermis are called:

1) Melanocytes

2) Langerhans cells

3) Merkel cells

4) Keratinocytes

Front 12

What is the function of melanocytes?

Back 12

Melanocytes function to produce a pigment called melanin.

Every individual has the same amount of melanocytes, however we all produce varied amounts of melanin. They are found in stratum basale.

Front 13

What is the function of the Langerhans cells?

Back 13

The Langerhans cells function as sensory cells found at the ends of the nerves. They make the epidermis sensitive to touch. They are found in stratum spinosum.

Front 14

What is the function of the merkel cells?

Back 14

The merkel cells function as immune cells that phagocytize foreign bodies in the epidermis. They are found in stratum basale.

Front 15

Describe stratum basale.

Back 15

Stratum basale consists of cells that constantly undergo mitosis, as they give rise to the other cells in the other layers. They also have the melanocytes and the merkel cells present.

Front 16

Describe stratum spinosum.

Back 16

Stratum spinosum has the keratinocytes and the langerhans cells present.

Front 17

Describe stratum granulosum.

Back 17

In stratum granulosum the cells are flattened, the nucleus and organelles are deteriorating and the cytoplasm is replaced with lamellar granules and keratohyaline granules.

Front 18

Describe stratus lucidum.

Back 18

It is know the be called stratus lucidum because it appears clear. Lucid is a direct translation of clear. It consists of only dead cells.

Front 19

Describe stratum corneum.

Back 19

In stratum corneum all cells are flat and dead, filled with keratin. The extracellular matrix, i.e. cytoplasm is replaced with glycolipids.

Front 20

What are the differences between thick and thin skin.

Back 20

The differences between thick and thin skin are:

1) Thick skin has five layers in the epidermis, whereas thin skin has four layers.

2) Thick skin has a short dermis, whereas thin skin has a long dermis.

3) Thick skin lacks hair, sebaceous glands and appocrine glands, whereas thin skin has hair, sebaceous glands and appocrine sweat glands.

4) Thick skin has merocrine/eccrine sweat glands, whereas thin skin doesn't have merocrine/eccrine sweat glands.

5) Thick skin is found on the fingertips, palms of hands and the soles of the feet, whereas the thin skin is found on the entire body.

6) The interface between the dermis and the epidermis in thick skin is extensive as it is long and closely spaced whereas, the interface between the dermis and epidermis is restricted in thin skin.

7) The stratum corneum has more cells per unit time in thick skin whereas, the stratum corneum has less cells per unit time in thin skin.

Front 21

Describe the dermis.

Back 21

The dermis is the layer found deep to the epidermis. It is made up of connective tissue and it consists of two layers.

Front 22

What are the two layers of the dermis?

Back 22

The two layers of the dermis are:

1) The papillary layer

2) The reticular layer

Front 23

Describe the papillary layer.

Back 23

The papillary layer is made up of areolar connective tissue. It is found directly beneath the epidermis. It consists of blood vessels, lymph and nerves. As well as thin collagen and elastic fibres.

Front 24

Describe the reticular layer.

Back 24

The reticular layer of the dermis is made up of irregular dense connective tissue. It is found deep to the papillary layer. It consists of lymph and nerves. As well as thick collagen and reticular fibres.

Front 25

Describe the hypodermis.

Back 25

The hypodermis is the subcutaneous layer. It is made up of adipose tissue and it contains sebaceous glands.

Front 26

What factors are involved with skin colour?

Back 26

There are three factors involved with skin colour:

1) Melanin pigment

2) Carotene pigment

3) The amount of blood and oxygen at the surface of skin

Front 27

Describe the melanin pigment.

Back 27

The melanin pigment is produced by the melanocytes. They are found in stratum basale. It produces a brown pigment.

Front 28

Describe the carotene pigment.

Back 28

The carotene pigment is found in adipocytes. It produces a yellow-orange pigment.

Front 29

Describe the blood and the hemoglobin.

Back 29

The colour of the skin is also dependent on the amount of blood that moves towards the surface of the skin and as well as the amount of oxygen carried by hemoglobin within the blood.

Front 30

How does the skin interact with ultraviolet light?

Back 30

When the skin is exposed to ultraviolet light, the melanocytes produce melanin which moves towards the surface of the skin. It must be noted that not enough melanin can be produced to protect the skin on the surface.

The presence of ultraviolet light increases melanin production.

Front 31

How is pigmentation caused?

Back 31

The process of pigmentation cam be described as:

1) Tyrosine

2) DOPA

3) Melanin

4) Melanoproteins

5) Melansomes

6) Keratinosytes

Front 32

Describe light skin complexion.

Back 32

Light complexioned skin have their melanin concentrated deep in their stratum basale.

Front 33

Does the number of melanocytes vary across race?

Back 33

No, it doesn't. Every individual has the same amount of melanocytes.

Front 34

So, what determines the complexion of an individual?

Back 34

There are three things that determine the complexion of an individual:

1) The amount of melanin produced.

2) The size of the melanosomes.

3) The degree of aggregation

Front 35

What are the appendages of the skin?

Back 35

The appendages of the skin are:

1) Hair

2) Epithelial glands

Front 36

Describe the epithelial glands found in the skin.

Back 36

There are two types of epithelial glands found in the skin:

1) Sebaceous glands

2) Sweat glands.

Front 37

Describe the sebaceous glands.

Back 37

The sebaceous glands are found in thin skin next to the hair follicles. They secrete an oily substance called sebum. The sebaceous glands develop during puberty. When the sebaceous glands secrete sebum into the dermis and it accumulates within the dermis, it causes inflammation and gives rise to acne/pimple.

Front 38

How many types of sweat glands are there?

Back 38

There are two types of sweat glands:

1) The apocrine sweat glands

2) The eccrine/merrocrine sweat glands

Front 39

Describe the merocrine/eccrine sweat glands.

Back 39

The merocrine/eccrine sweat glands secrete clear and non-smelling sweat. They are found all over the body and are more common in thick skin such as the fingertips, palms and soles of the feet. They are involved with thermoregulation.

Front 40

Describe the apocrine sweat glands.

Back 40

The apocrine sweat glands produce smelly sweat. The sweat consists of a lot of proteins which, are ingested by bacteria resulting in a foul smell. The apocrine sweat glands are found in the nipples, genitals, anus and armpits. The apocrine sweat glands develop during puberty and remain throughout adulthood. The apocrine sweat gland are also involved with thermoregulation.

Front 41

What do both the merocrine/eccrine and apocrine sweat glands have in common?

Back 41

Both types of sweat glands have myoepithelial tissue in common. They are able to contract and secrete.

Front 42

What are nerve endings?

Back 42

Nerve endings are receptors that provide sensory functions such as touch and pressure. They are common in epithelial tissue.

Front 43

What are the two types of nerve endings found in the skin?

Back 43

The two types of nerve endings found in the skin are:

1) Meisner's corpuscles

2) Pacinian corpuscles

Front 44

Describe Meisner's corpuscles.

Back 44

Meisner's corpuscles are receptors that sense light touch. They are found in hairless regions (i.e. thick skin) such as the fingertips, palms of hands and soles of feet.

Front 45

Describe Pacinian corpuscles.

Back 45

Pacinian corpuscles are receptors that sense pressure. They are found in the reticular layer of the dermis, near the sebaceous tissue (hypodermis), tendons and ligaments.