Week 35 / Skin 2

Question 1

Question 1:
What is the mechanism by which the skin protects against microorganisms?

Question 2:
How does the skin protect against dehydration?

Question 3:
What role do melanins play in protecting the skin?

Question 4:
How does the skin protect against mechanical trauma?

Question 5:
How do somatic sensory receptors in the skin function?

Answer 1

Answer 1:
The skin protects against microorganisms through a surface film/mechanical barrier, which prevents the entry of pathogens.

Answer 2:
The skin protects against dehydration by using keratin in the epidermis to form a waterproof barrier that prevents excessive water loss.

Answer 3:
Melanins in the skin absorb ultraviolet radiation, providing protection from UV light that can damage deeper layers of the skin.

Answer 4:
The skin’s tissue strength helps protect against mechanical trauma like cuts and abrasions.

Answer 5:
Somatic sensory receptors in the skin detect sensations such as pain, heat, cold, pressure, and touch, transmitting these sensations to the brain.

Question 2

Question 6:
What allows the skin to permit movement and body growth?

Question 7:
What is the skin’s role in vitamin D production?

Question 8:
What does the skin excrete?

Question 9:
How does the skin support immunity?

Question 10:
How does the skin regulate body temperature?

Answer 2

Answer 6:
The skin’s elastic and recoil properties allow for movement and growth without injury, especially due to the flexibility provided by the subcutaneous tissue.

Answer 7:
The skin plays an endocrine role in vitamin D production by activating a precursor compound in the skin when exposed to ultraviolet light.

Answer 8:
The skin excretes water, urea, ammonia, and uric acid through sweat, aiding in waste elimination.

Answer 9:
The skin aids in immunity by destroying microorganisms and interacting with immune system cells, such as helper T cells, through phagocytic cells and epidermal dendritic cells.

Answer 10:
The skin regulates body temperature through sweat production, blood flow regulation to the skin, and evaporation of sweat, helping to maintain heat loss or retention.

Question 3

Question 2:
How does the skin protect against microorganisms and harmful chemicals?

Answer 3

Answer 2:
The skin has a supply of immune cells and chemicals that resist microbes and other pathogens, offering protection against invasion by harmful microorganisms and chemicals.

Question 3

Question 1:
What type of cells cover the epidermis and what is their role in protection?

Answer 3

Answer 1:
The keratinized stratified squamous epithelial cells cover the epidermis, forming a barrier that protects underlying tissues from microorganisms, harmful chemicals, and mechanical injury.

Question 4

Question 3:
What role does the skin play in protecting against dehydration?

Answer 4

Answer 3:
The skin protects against dehydration by minimizing the loss of internal body fluids and preventing the unwanted entry of fluids from the external environment.

Question 5

Question 1:
What is the surface film on the skin, and how is it produced?

Answer 5

Answer 1:
The surface film is a thin layer of emulsified material spread over the skin’s surface. It is produced by the mixing of residue and secretions from sweat and sebaceous glands with epithelial cells that are constantly being shed from the epidermis.

Question 5

Question 2:
What is desquamation in relation to the skin?

Answer 5

Answer 2:
Desquamation is the process of shedding epithelial cells from the surface of the skin, which helps to maintain the skin’s protective barrier.

Question 6

Question 3:
What role do microbial cells play in the skin’s surface film?

Answer 6

Answer 3:
Microbial cells are an important part of the surface film, contributing to the skin microbiome, which plays a role in maintaining the health and protection of the skin.

Question 7

Question 4:
What is an example of a microorganism found on the surface film of the skin?

Answer 7

Answer 4:
An example of a microorganism found on the surface film of the skin is a face mite, which resides on the skin’s surface and is part of the skin microbiome.

Question 8

Question 1:
How much water evaporates through the stratum corneum daily?

Answer 8

Answer 1:
Approximately 400 mL of water evaporates through the stratum corneum daily.

Question 9

Question 2:
What substances are excreted through sweat?

Answer 9

Answer 2:
Through sweat, small amounts of salts, carbon dioxide, ammonia, and urea are excreted from the body.

Question 10

Question 3:
What is a key function of sweat besides excreting substances?

Answer 10

Answer 3:
Sweat also serves to remove heat from the body, helping to regulate body temperature.

Question 11

Question 4:
How can certain drugs be administered through the skin?

Answer 11

Answer 4:
Certain drugs can be absorbed through the skin by applying patches, ointments, or gels, allowing for transdermal drug delivery.

Question 12

Question 1:
What percentage of heat transfer occurs through the skin?

Answer 12

Answer 1:
80% or more of heat transfer occurs through the skin.

Question 13

Question 2:
How is heat loss regulated through the skin?

Answer 13

Answer 2:
Heat loss can be regulated by altering the flow of blood in the skin.

Question 14

Question 3:
What is vasoconstriction?

Answer 14

Answer 3:
Vasoconstriction is the narrowing of blood vessels in the skin, which helps conserve heat.

Question 15

Question 4:
What is vasodilation?

Answer 15

Answer 4:
Vasodilation is the widening of blood vessels in the skin, which helps release excess heat from the body.

Question 16

Question 5:
How does blood flow contribute to temperature regulation?

Answer 16

Answer 5:
Blood flow in the skin helps regulate body temperature by adjusting heat loss through vasoconstriction or vasodilation.

Question 17

Where is hair absent on the body?

Answer 17

Answer 1:
Hair is absent on the palms, fingertips, and soles of the feet.

Question 18

Question 1:
What function does hair on the head serve?

Question 2:
What role do eyebrows and eyelashes play?

Question 3:
What function does hair in the nostrils serve?

Question 4:
How do hair root plexuses function?

Answer 18

Answer 1:
Hair on the head guards the scalp from injury and the sun’s rays and decreases heat loss from the scalp.

Answer 2:
Eyebrows and eyelashes protect the eyes from foreign particles.

Answer 3:
Hair in the nostrils protects against the inhalation of particles.

Answer 4:
Hair root plexuses, associated with hair follicles, are activated whenever a hair is moved, even slightly, allowing hair to function in sensing light touch.

Question 18

Question 2:
Where is hair heavily distributed on the body?

Answer 18

Answer 2:
Hair is heavily distributed on the scalp, eyebrows, axillae (armpits), and around the external genitals.

Question 18

Question 2:
Why does grey or white hair appear grey or white?

Answer 18

Answer 2:
Grey hair appears due to low melanin, and white hair appears due to no melanin. Both also appear grey/white because of the diffusion of light through the translucent hair shaft.

Question 19

Question 3:
What determines the thickness and distribution of hair?

Answer 19

Answer 3:
Genetic and hormonal influences determine the thickness and distribution of hair.

Question 20

What determines the color of hair?

Answer 20

Answer 1:
The color of hair is determined by the amount, type, and distribution of melanin deposited in the cells of the hair, typically in the medulla

Question 21

Question 1: What happens during the growth stage (anagen) of the hair growth cycle? Question 2: What occurs during the regression stage (catagen) of the hair growth cycle? Question 3: What happens during the resting stage (telogen) of the hair growth cycle?

Answer 21

Answer 1: During the growth stage (anagen), cells of the hair matrix divide. New cells are added to the base of the hair root, causing existing cells of the hair root to be pushed upward, and the hair grows longer. Answer 2: During the regression stage (catagen), the hair moves away from the blood supply in the papilla of the hair. Cells of the hair matrix stop dividing, and the hair follicle shrinks. Answer 3: During the resting stage (telogen), the hair root falls out or is pushed out of the hair follicle, and the new growth stage begins.

Question 22

Question 1: Where are eccrine sweat glands distributed on the body?

Answer 22

Answer 1: Eccrine sweat glands are distributed over the entire body surface, except for the lips, ear canal, and nail beds.

Question 23

Question 3: What does eccrine sweat consist of?

Answer 23

Answer 3: Eccrine sweat is a transparent, watery liquid rich in salts, ammonia, uric acid, urea, and other wastes.

Question 24

Question 2: What is the structure of eccrine sweat glands?

Answer 24

Answer 2: Eccrine sweat glands are simple, coiled, tubular type glands.

Question 25

Question 4: What is the main function of eccrine sweat glands?

Answer 25

Answer 4: The main function of eccrine sweat glands is temperature regulation.

Question 26

Where are apocrine sweat glands located on the body?

Answer 26

Answer 1: Apocrine sweat glands are located deep in the subcutaneous layer, specifically in areas like the armpits, eyelids, areola, genitalia, perineum, and ears.

Question 27

Question 2: How do apocrine sweat glands differ in size compared to eccrine sweat glands?

Answer 27

Answer 2: Apocrine sweat glands are larger compared to eccrine sweat glands.

Question 28

Question 3: What is the connection between apocrine sweat glands and hair follicles?

Answer 28

Answer 3: Apocrine sweat glands are connected to hair follicles.

Question 29

Question 4: How does the secretion of apocrine sweat glands differ from eccrine sweat glands?

Answer 29

Answer 4: The secretion of apocrine sweat glands is more viscous than that of eccrine sweat glands.

Question 30

Question 5: What causes the odour associated with apocrine sweat glands?

Answer 30

Answer 5: The odour associated with apocrine sweat glands is caused by the decomposition of the secretion by skin bacteria.

Question 31

Question 1: How do eccrine glands secrete their fluids? Question 2: How do apocrine glands secrete their fluids? Question 3: Where are eccrine glands located on the body? Question 4: Where are apocrine glands found? Question 5: What is the type of fluid secreted by eccrine glands? Question 6: What type of fluid do apocrine glands secrete? Question 7: What is the primary function of eccrine glands? Question 8: What is the function of apocrine glands? Question 9: What is unique about the pheromone marking in mammals?

Answer 31

Answer 1: Eccrine glands secrete fluids directly through a duct onto the skin surface. Answer 2: Apocrine glands secrete substances indirectly into the external skin surface. Answer 3: Eccrine glands are present on all areas of the body, except the areas where apocrine glands are located. Answer 4: Apocrine glands are found in areas like the areola of the breast, armpits, ears, eyelids, perineum, and other similar areas. Answer 5: The fluid secreted by eccrine glands is thin and clear watery sweat. Answer 6: Apocrine glands secrete a thick, clear fluid. Answer 7: Eccrine glands primarily act as thermoregulatory glands to help regulate body temperature. Answer 8: Apocrine glands secrete pheromonic chemicals that are believed to attract the opposite sex. Answer 9: Pheromone marking in mammals involves rubbing against mates, transferring the contents of apocrine glands to communicate with others.

Question 32

Question 1: What do sebaceous glands secrete?

Answer 32

Answer 1: Sebaceous glands secrete oil for the hair and skin, called sebum.

Question 32

Question 2: Where are sebaceous glands located?

Answer 32

Answer 2: Sebaceous glands are located wherever hairs grow from the skin.

Question 32

Question 3: What is the function of the oil secreted by sebaceous glands?

Answer 32

Answer 3: The oil (sebum) secreted by sebaceous glands keeps the hair supple and the skin soft and pliant.

Question 33

Question 4: What is the role of sebaceous glands in preventing water loss?

Answer 33

Answer 4: Sebaceous glands secrete sebum, which acts as nature's own skin cream, helping to prevent excessive water loss from the epidermis.

Question 34

What is the main function of sebum?

Answer 34

Answer 1: Sebum is antifungal and helps protect the skin from numerous types of fungal infections.

Question 35

Question 2: What are the main components of sebum?

Answer 35

Answer 2: Sebum is made from oils, including: Triglycerides Fatty acid breakdown products Wax esters Squalene Cholesterol

Question 36

Question 3: Where are sebaceous glands located?

Answer 36

Answer 3: Sebaceous glands are located in the dermis, except in the skin of the palms and soles.

Question 36

Question 5: What happens when sebum accumulates in sebaceous gland ducts?

Answer 36

Answer 5: When sebum accumulates in and enlarges the ducts of the sebaceous glands, it can form white pimples. With oxidation, this sebum darkens and forms a blackhead.

Question 36

Question 4: How does sebum secretion change during adolescence?

Answer 36

Answer 4: Sebum secretion increases during adolescence due to hormonal control, which can lead to acne.

Question 37

What are the roles of sebum

Answer 37

Surface lubrication Prevents drying Waterproof barrier Prevents loss of heat and water Antimicrobial Pro-inflammatory Anti-inflammatory Transports pheromones to surface

Question 38

Question 1: What type of glands are ceruminous glands?

Answer 38

Answer 1: Ceruminous glands are specialist apocrine sweat glands.

Question 39

Question 2: Where are ceruminous glands located, and how do they function?

Answer 39

Answer 2: Ceruminous glands are located in the external ear canal and open into the canal or the necks of hair follicles in the area. They secrete cerumen (earwax), a mixture of sebaceous and ceruminous gland secretions.

Question 39

Question 3: What is cerumen (earwax) and what role does it play?

Answer 39

Answer 3: Cerumen is a brown substance formed by the mixed secretions of sebaceous and ceruminous glands. It helps protect the ear canal from dehydration, lubricates, and cleans the canal.

Question 39

Question 4: How does cerumen protect the ear canal?

Answer 39

Answer 4: Cerumen helps to waterproof the ear canal, keep the eardrum pliable, kill bacteria, and trap foreign particles.

Question 40

Question 5: What happens if there is an excess of cerumen in the ear canal?

Answer 40

Answer 5: Excess cerumen can harden, causing a blockage in the ear, which may result in hearing loss.

Question 41

Question 1: What is the main function of the mammary gland?

Answer 41

Answer 1: The main function of the mammary gland is the production and expression of milk, which provides nourishment and immune protection for offspring.

Question 42

Question 2: What is required for the development of mammary glands?

Answer 42

Answer 2: The development of mammary glands requires the coordinated action of many hormones.

Question 43

Question 3: What are mammary glands composed of?

Answer 43

Answer 3: Mammary glands are composed of specialized epithelium and stroma.

Question 44

Question 4: What types of lesions can mammary glands give rise to?

Answer 44

Answer 4: Mammary glands may give rise to both benign and malignant lesions.

Question 45

Question 1: What happens to the lobules in the mammary glands during pregnancy?

Answer 45

Answer 1: During pregnancy, the lobules undergo controlled proliferation and enlargement in preparation for lactation.

Question 46

Question 2: What increases in each lobule during pregnancy?

Answer 46

Answer 2: During pregnancy, the acini in each lobule markedly increase.

Question 47

Question 3: What do epithelial cells in the mammary glands do during pregnancy?

Answer 47

Answer 3: Epithelial cells in the mammary glands become differentiated and start to synthesize and secrete milk.

Question 48

Question 4: Which hormone is necessary for the initiation of lactation after birth?

Answer 48

Answer 4: Prolactin is necessary for the initiation of lactation after birth.

Question 49

Question 5: What happens to the breast structure after breastfeeding ceases?

Answer 49

Answer 5: After breastfeeding ceases, there is a rapid change in the differentiated lobular structure, and the breast returns to its pre-pregnancy structure.

Question 50

What are the Functions of the Integumentary System?

Answer 50

* Regulates body temperature. * Protects body from external environment * Stores blood. * Detects cutaneous sensations. * Excretes and absorbs substances. * Synthesizes vitamin D.