Chapter 5 - Integumentary System Flashcards Preview

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Flashcards in Chapter 5 - Integumentary System Deck (136)
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0

What is the integumentary system?

A group of organs working together - the skin, hair, oil and sweat glands, nails and sensory receptors

1

What are the 6 functions of the integumentary system?

1. Regulates body temperatures
2. Stores blood
3. Protects body from external environment
4. Detects cutaneous sensations
5. Excretes and absorbs substances
6. Synthesizes vitamin D

2

What does a bluish skin colour indicate?

Hypoxia - oxygen deficiency at the tissue level
A sign of heart failure

3

What is the dermatology?

The medical specialty that deals with the diagnosis and treatment of integumentary system disorders

4

What is the cutaneous membrane?

The skin
Covers the external surface of the body

5

What are the two main parts that make up the skin?

1. Epidermis
2. Dermis

6

Describe the epidermis.

The superficial, thinner portion which is composed of EPITHELIAL TISSUE
Avascular

7

Describe the dermis.

The deeper, thicker, CONNECTIVE TISSUE portion
Vascular

8

What is the subcutaneous layer?

Also called the hypodermis
Consists of areolar and adipose tissues
Fibers that extend from the dermis anchor the skin to the subcutaneous layer

9

What does the subcutaneous layer serve as?

Storage deposit for fat and contain large blood vessels that supply the skin

10

What are pacinian (lamellated) corpuscles?

Nerve endings in the subcutaneous layer, and sometimes in the dermis that are sensitive to pressure

11

What is the epidermis composed of? What 4 kinds of cells?

Keratinized stratified squamous epithelium cells
1. Keratinocytes
2. Melanocytes
3. Langehans cells
4. Merkel cells

12

What do keratinocytes do?

Produce the protein keratin - a tough fibrous protein that helps protect the skin and underlying tissues from abrasions, heat, microbes, and chemicals
Arranged in 4 or 5 layers

13

What are lamellar granules?

Release a water-repellant sealant that decreases water entry and loss and inhibits the enters of foreign materials

14

What do melanocytes do?

Produce the pigment melanin
Their long slender projections extend between keratinocytes and transfer melanin granules to them

15

What is melanin?

A yellow-red or brown-black pigment that contributes to skin colour and absorbs damaging ultraviolet light

16

What do melanin granules do once they're inside keratinocytes?

They cluster to form a protective veil over the nucleus, on the side towards the skin surface
They shield nuclear DNA from damage

17

What are langerhans cells?

Also called epidermal dendritic cells
Arise from red bone marrow and migrate to the epidermis
They participate in immune responses against microbes that invade the skin

18

What are merkel cells?

Located in the deepest layer of the epidermis, where they contact the flattened process of a sensory neuron called a merkel disc
Detect touch sensations

19

What are the layers of thin skin called?

1. Stratum basale
2. Stratum spinosum
3. Granulosum
4. Thin stratum corneum

20

What are the layers of thick skin called?

1. Stratum basale
2. Stratum spinosum
3. Stratum Granulosum
4. Stratum lucidum
5. Thick stratum corneum

21

Describe the stratum basale.

Deepest layer
Composed of a single row of cuboidal or columnar keratinocytes
Some cells in this layer are stem cells that produce new keratinocytes

22

Describe stratum spinosum

Superficial to the stratum basale
Consists of keratinocytes arranged in 8-10 layers
Cells in more superficial layers become flattened
Some cells retain their ability to divide

23

Describe the stratum granulosum

Superficial to the stratum spinosum
Consists of 3-5 layers of flattened keratinocytes that are undergoing apoptosis - programmed cell death
Father away from their source of nutrition

24

What is the distinctive feature of the cells in the stratum granulosum layer?

The presence of darkly staining granules of protein called keratohyalin

25

What is keratohyalin?

It assembles keratin intermediate filaments into keratin

26

What marks the transition between the deeper, metabolically active strata and the dead cells of the superficial strata?

The stratum granulosum

27

What is stratum lucidum?

Present only in thick skin
Consists of 4-6 layers of flattened CLEAR, dead keratinocytes that contain large amounts of keratin and thickened plasma membranes

28

What is the stratum corneum?

Consists of 25-30 layers of flattened dead keratinocytes
Can range from a few cells to many
Cells no longer contain organelles
Cells are continuously shed

29

What is kertiniziation?

A process whereby cells accumulate more and more keratin as they are slowly pushed to the surface