Integumentary System

Question 1

What is the integumentary system?

Answer 1

the skin and the accessory structures

Question 2

What does the integumentary system do?

Answer 2

protects, regulates temperature, senses things, begins the synthesis of Vitamin D

Question 3

What are the three layers of skin?

Answer 3

epidermis, dermis, hypodermis (subcutaneous layer)

Question 4

What are general traits of the epidermis?

Answer 4

made of stratified squamous epithelium; completely avascular (no blood vessels); thin areas can be 0.1 mm thick, thickest skin can be 1.5 mm; contains very few nerve endings;broken into five layers; 95% of the cells are keratinocytes

Question 5

Five layers of epidermis

Answer 5

stratum corneum; stratum lucidum; stratum granulosum; stratum spinosum, stratum basale

Question 6

What is stratum corneum?

Answer 6

dead, flat keratinocytes completely wrapped in keratin

Question 7

What is stratum lucidum?

Answer 7

dead and flattened keratinocytes that give an extra layer

Question 8

What is stratum granulosum?

Answer 8

keratinocytes expel liquids to form a barrier

Question 9

What is stratum spinosum?

Answer 9

keratinocytes connect to one another with desmosomes; cells start to differentiate, and they cannot divide anymore

Question 10

What is stratum basale?

Answer 10

keratinocyte-making stem cells and other cells are here; this is where the keratinocytes from the other layers were “born”, and they gradually pushed outwards; only found in thickest parts of skin

Question 11

What are desmosomes?

Answer 11

specialized structures that use multiple different adhesion proteins to hold cells together and minimize the space between cells

Question 12

What three cell types does stratum basale have?

Answer 12

Melanocytes, Merkel Cells, Langerhans cells

Question 13

What are melanocytes?

Answer 13

produce black pigment called melanin. they produce more melanin in response to sunlight exposure. package small amounts of pigment in organelles called melanosomes. melanin absorbs UV rays from sunlight

Question 14

What is skin color a factor of, and what is it NOT determined by?

Answer 14

it’s a factor of the number of melanosomes in the skin, and it’s not determined by the number of melanocytes

Question 15

What does melanocytes generally have in their structure?

Answer 15

dendrites; the long projections reach into more superficial layers

Question 16

What are Merkel cells?

Answer 16

a type of mechanoreceptor, and they sense any outside movement, and convey the message to the nerves; only mechanoreceptor in the epidermis. they are the best at detecting light pressure, as well as texture and edges of shapes; most densely found in fingertips

Question 17

What do Merkel cells sit on top of?

Answer 17

sensory neurons; pass info to these neurons, and they’re carries to be processed

Question 18

What are Langerhans cells?

Answer 18

a type of dendritic cell unique to the skin. dendritic cells are a type of antigen-presenting phagocyte, which are a type of white blood cell. Langerhans cells are considered the first line of defense for the immune system. Should an invader enter the immune system, the Langerhans cells will basically destroy it

Question 19

What is the dermis?

Answer 19

the dermis is under the epidermis, and it is also thicker than the epidermis. it has vasculature. the dermis and epidermis just kind of “cross” into each other, and the dermis protrudes into the epidermis to give nutrients. the protrusions are called dermal papillae, and they are responsible for unique fingerprints

Question 20

What are the 2 types of glands in the dermis?

Answer 20

Sebaceous glands and sweat glands

Question 21

What are sebaceous glands?

Answer 21

glands that are responsible for producing and secreting an oil called sebum. typically found attached to hair follicles

Question 22

What are the two types of sweat glands?

Answer 22

eccrine and apocrine

Question 23

What are eccrine glands?

Answer 23

sweat glands that simply release water to cool down the body’s temperature. usually release their liquid directly onto the skin

Question 24

What are apocrine glands?

Answer 24

a special sweat gland located in the armpits and groin area. they release extra oil into their secreted fluid. responsible for smelly compounds, or natural musk. usually release their secretions into a hair follicle

Question 25

What are Meissner’s corpuscles?

Answer 25

a type of mechanoreceptor that is on the superficial side of the dermis. detect light touch sensations, and they help people read braille

Question 26

What are Pacinian corpuscles?

Answer 26

a type of mechanoreceptor that is the deepest of all four. only register large amounts of pressure on the skin. detect heavier touch and vibrations

Question 27

What are Ruffini’s corpuscles?

Answer 27

a type of mechanoreceptor that are entirely in the dermis, but not as deep at Pacinian corpuscles. not much is known about this corpuscle, however it’s thought that they mostly detect stretching, or how firmly you are grasping an object

Question 28

Describe 1st, 2nd, 3rd, and 4th degree burns

Answer 28

First- part of the epidermis
2nd- all epidermis and some dermis
3rd-all epidermis and dermis
4th- damage all skin and underlying muscle/bone