WEEK 7

Question 1

Identify and describe the components of the integumentary system.

Question 2

List and identify all the organs and accessory structures of the integumentary system.

Answer 2

skin, epidermis, dermis, stratum basal layer, stratum spinosum layer, stratum granulosum layer, stratum lucid layer, stratum corneum, papillary region, reticular region, hypodermic, hair, sebaceous and sudoriferous glands, ceruminous glands.

Question 3

Define “organ”. Explain why the skin specifically would fit your definition of an organ.

Answer 3

an organ is a a structure with defined form and function, is composed of 2 or more tissues.
Skin is spread out over layers over the surface and has several functions such as protection, temperature regulation, sensation, excretion, and synthesis of vitamin D.

Question 4

For the two layers of the dermis, state their proper anatomical name and the specific tissue type
of which each is primarily composed.

Answer 4

Papillary region: made up of loose areolar connective tissue and contains blood vessels and sensory receptors.

Reticular region: made up of dense regular connective tissue with bundle of collagen and elastic fibers. Gives skin its strength, flexibility, and elasticity.

Question 5

Identify the accessory structures of the skin that are embedded in each of the two layers of the
dermis.

Answer 5

hair, sebaceous glands, sudoriferous glands, cerumineous gland.

Question 6

Draw an annotated diagram of the skin, clearly showing:
◦ ◦
◦ ◦
The epidermal and dermal layers of the skin, and the hypodermis
The type(s) of tissue of that comprise each of the above layers indicated above (hint: refer back to the Tissue Structure topic)
The layer(s) of the skin that contain(s) blood vessels
The layer(s) of the skin that contain(s) nervous structures

Question 7

Identify and describe the five layers of the epidermis of the skin, including the location and function of keratinocytes and melanocytes.

Answer 7

stratum basale: rapidly dividing keratinocytes and melanocytes to replenish cells above it(alive cell)
- single row of cuboidal or columnar cells

stratum spinosum: 8 to 10 rows of live keratinocytes and melanocytes packed tightly together containing pre-keratin

stratum granulosum: 3 to 5 rows of flattened dying keratinocytes loosing nuclei and organelles.
- contains granules of keratohyalin

stratum lucidum: only in area where skin is thick(palm, soles, fingers)
- clear, flat, dead keratinocytes
- contains eleidin(eventually formed into keratin)

stratum corneum: flat, closely packed, dead keratinocytes(20-30 layers of cells)
- keratin instead of cytoplasm
- glycolipids in extracellular space
- this layer is the one that its shed during abrasion

Question 8

Draw an annotated diagram of the epidermis of thick skin, clearly showing the five layers of the epidermis and specifying the distinguishing physical characteristics of each layer.

Question 9

Identify which layer in the diagram you created above would be missing from thin skin.

Question 10

Specify the two main types of cells found in the epidermis, and which important chemical each of them produce. Briefly explain how each of those chemicals provide protection to underlying tissues.

Answer 10

2 main types of cells: keratinocytes and melanocytes
keratinocytes: produces keratin, helps protect the skin by keeping it water proof
melanocytes: produce melanin, protects kin from UV rays and is all a pigment for skin involved with skin colour

Question 11

Specify the function(s) of epidermal derivatives, including hair, sebaceous glands, sudoriferous glands, ceruminous glands, nails.

Answer 11

hair: protection and provides sensitivity to touch

sebaceous glands: produces oil to keep hair from drying out, keeps skin waterproof, soft, and pliable

sudoriferous glands: produces sweat to control body temperature and excrete chemical waste

ceruminous glands: modified sweat glands that produce earwax in auditory canal of the ear

nails: hard keratinized masses of cells, provide protection of fingers/toes, assist in object manipulation, scratching.

Question 12

List the main function(s) served in human by the hairs of the:
◦ Scalp
◦ Eyelids
◦ Nostrils
◦ Rest of the body

Question 13

What is the main function(s) of nails, and what about their structure allows them to perform that function(s)?

Answer 13

nails: hard keratinized masses of cells, provide protection of fingers/toes, assist in object manipulation, scratching.

Question 14

Complete the following table regarding integumentary glands:

Question 15

Describe five major functions of the integumentary system.

Answer 15

protection
temp regularion
excretion
vitamin D
sensation

Question 16

Explain the mechanisms by which the integumentary system carries out each of the following
functions:
◦ Protection
◦ Body temperature regulation
◦ Sensation
◦ Synthesis of vitamin D
◦ Excretion

Answer 16

protection:
- mechanical: keratin in outermost layer
- prevents dehydration: lipid secretions from cells and glands
- UV radiation protection: melanin in melanocytes and keratinocytes absorb UV radiation
- Antimicrobial protection: Langerhans cells and macrophages can activate the immune response after encountering a pathogen; sebaceous glands contain antimicrobial substances.

body temp:
- help in regulation body temperature
- sudoriferous glands produce sweat to reduce heat

sensation:
- contains various various receptors which detect various stimuli.
-> mechanoreceptors(touch, pressure)
-> thermorceptors(temp)
-> nociceptors(pain)

Excretion:
- removes waste products (salts, urea, ammonia, CO2) from body
- sweating removes variety of chemical wastes in small amounts

synthesis of vitamin D
- UV radiation from sun stimulates the skin to convert an inactive form of vitamin d into an active form
- vitamin d is needed to absorb calcium