Integumentary System

Question 1

What does the integumentary system include?

Answer 1

Skin (epidermis + dermis), hypodermis (subcutaneous layer), glands, nails, and hair.

Question 2

What are the two main layers of the skin?

Answer 2

Epidermis (outer layer) and dermis (inner layer).

Question 3

What is the hypodermis?

Answer 3

Also called the subcutaneous layer; it lies beneath the dermis and stores fat. It’s mostly made of adipose and areolar connective tissue.

Question 4

Where are hair follicles, sebaceous glands, and sweat glands located?

Answer 4

In the dermis.

Question 5

What tissue type makes up the dermis?

Answer 5

Connective tissue
Primarily made of dense irregular connective tissue with collagen and elastic fibers.

Question 6

What are the five layers of the epidermis (from outermost to innermost)?

Answer 6

Come Lick Grey Sweaty Balls

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale.

Question 7

What are the four main cell types found in the epidermis?

Answer 7

Keratinocytes, melanocytes, Langerhans cells, and Merkel cells.

Question 8

What is the function of keratinocytes?

Answer 8

They produce keratin and form the structural barrier of the skin.

Question 9

What do melanocytes do?

Answer 9

They produce melanin, the pigment responsible for skin color.

Question 10

What is the role of Langerhans cells in the skin?

Answer 10

They are immune cells derived from monocytes produced in the bone marrow and carry out phagocytosis.

Question 11

What is the function of Merkel cells?

Answer 11

They are involved in sensory reception, especially touch.

Question 12

What is found in the stratum corneum?

Answer 12

Dead, flat, enucleated keratinocytes filled with keratin.

Question 13

Where is the stratum lucidum found?

Answer 13

Only in thick skin—palms and soles.

Question 14

What happens in the stratum granulosum?

Answer 14

Keratinocytes flatten, accumulate granules, and begin to die.

Question 15

Which cells are found in the stratum spinosum?

Answer 15

Keratinocytes and Langerhans cells.

Question 16

What occurs in the stratum basale?

Answer 16

Mitosis of keratinocytes, and presence of melanocytes, Merkel cells, and stem cells.

Question 17

What is keratin and what produces it?

Answer 17

Keratin is a tough, water-insoluble protein produced by keratinocytes.

Question 18

What are lamellar bodies and which cells produce them?

Answer 18

Lamellar bodies are lipid-rich molecules produced by keratinocytes; they help make the skin impermeable to water.

Question 19

Why are keratinocytes important for skin renewal?

Answer 19

They are mitotically active and constantly renewed to maintain the epidermis.

Question 20

Why is the stratum corneum important for protection against viruses like HPV?

Answer 20

It is made of dead, enucleated, keratinized cells, which cannot support viral replication because they lack genetic machinery.

Question 21

What type of cells make up the stratum corneum?

Answer 21

Enucleated, dead keratinocytes filled with keratin.

Question 22

How does the keratinized layer of skin prevent viral entry?

Answer 22

Viruses cannot infect or replicate in dead cells that lack nuclei and cellular machinery.

Question 23

What could happen if the stratum corneum was absent or damaged?

Answer 23

Pathogens like HPV could infect live basal cells more easily without needing a cut in the skin.

Question 24

What two major substances do keratinocytes produce that contribute to the skin’s protective barrier?

Answer 24

Keratin (protein barrier) and lamellar bodies (lipid barrier).

Question 25

What are the two layers of the dermis?

Answer 25

The papillary layer (20%, areolar connective tissue) and the reticular layer (80%, dense irregular connective tissue).

Question 26

What is the function of dense irregular connective tissue in the reticular layer?

Answer 26

It resists tension and tearing in multiple directions.

Question 27

What structures are found in the dermis?

Answer 27

Blood and lymphatic vessels, nerves, hair follicles, arrector pili muscles, sebaceous glands, sweat glands, and sensory corpuscles.

Question 28

What types of cells are in the dermis?

Answer 28

Fibroblasts (produce fibers), mast cells (immune response), and macrophages (phagocytosis).

Question 29

What do sebaceous glands secrete and what stimulates them?

Answer 29

They secrete sebum (moisturizes and protects skin), stimulated by androgens.

Question 30

Where are sebaceous glands absent?

Answer 30

Palms, soles

Question 31

What is the difference between eccrine and apocrine sweat glands?

Answer 31

Eccrine glands secrete watery sweat for thermoregulation; apocrine glands secrete viscous sweat, often in response to stress.

Question 32

What are two modified apocrine glands?

Answer 32

Mammary glands (milk) and ceruminous glands (earwax).

Question 33

What are corpuscles?

Answer 33

Sensory receptors in the dermis for touch, pressure, and temperature.

Question 34

What tissues make up the hypodermis?

Answer 34

Mostly adipose tissue and some areolar connective tissue.

Question 35

What are the functions of the hypodermis?

Answer 35

Thermoregulation, insulation, and energy storage.