Lab 2.1

Question 1

Epidermis

Structure?

Function?

Answer 1

The outer, thinner layer conprised of a stratified squamous epithelium

-Prevents water loss and entry of chemicals and microorganisms, protects against ultraviolet light, produces vit D

Question 2

Dermis

Structure?

Function?

Answer 2

Inner, thicker connective tissue layer - 2 layers

Responsible for structural strength and flexibility of the skin. Epidermis Exchanges gases, nutrients and waste products with the blood in the dermis

Question 3

What are the accessory structures of the integumentary system?

Answer 3

Sweat glands

Hair

nails

sebaceous glands

Question 4

What are the 5 layers of the epidermis?

Answer 4

Stratum basale - bottom later

Stratum spinosum

Stratum granulosum

Stratum lucidum - not present in thin skin

Stratum corneum - top layer

Question 6

Name the layer

Which layer in epidermis?

of layers / cell type

Structure?

Function?

Answer 6

Stratum Basale

• Deepest portion of epidermis
• Single layer of cubodial or columnar cells
• Epidermis is anchored to basement membrane with hemidesmosomes
• Melanocytes produce and contribute melanin, which protects against ultra violet light

Question 7

Name the layer

Which layer in epidermis?

of layers / cell type

Structure?

Function?

Answer 7

Stratum spinosum

• on top of stratum basale (2nd layer up)
• Composed of 8-10 layers of many sided cells, as they push to the surface they flatten - desmosomes break apart and reform
• Keratin fibers and lamellar bodies form inside the cells

Question 8

Name the layer

Which layer in epidermis?

of layers / cell type

Structure?

Function?

Answer 8

Stratum granulosum

3rd layer up

• 2-5 layers of flat diamond shaped cells
• produces keratohyalin granules, lamellar bodies release lipids from cells, cells die

Question 9

Subcutaneous tisse

Structure?

Function?

Answer 9

Not part of the skin, loose connective tissue with abundant deposits of adipose tissue

Attaches dermis to underlying structures, provides energy, insulation and padding

Question 10

Name the layer

Which layer in epidermis?

of layers / cell type

Structure?

Function?

Answer 10

Stratum lucidum

4th layer from bottom

3-5 layers of dead cells, present in thick skin only

-Disperses keratohyalin around keratin fibers

Question 11

Name the layer

Which layer in epidermis?

of layers / cell type

Structure?

Function?

Answer 11

Stratum corneum

top layer / superficial part of skin

25 or more layers of dead squamous cells

Question 12

Name the structure

Answer 12

• fingerlike projections arranged into double rows
• increasing the surface area between the epidermis and dermis
• strengthening the juncture with the epidermis and increasing the amount exchange of oxygen, nutrients, and waste.

Question 13

Name the gland

Answer 13

Apocrine sweat gland

continuously secrete a concentrated fatty sweat into the gland tube

Simple cuboidal,. large lumen

Question 14

Name the gland

Answer 14

Eccrine/Merocrine sweat gland

Stratified cuboidal - Small lumen

Eccrine glands occur over most of your body and open directly onto the surface of your skin.

Question 15

Name the gland

Answer 15

Sebaceous glands

a small gland in the skin which secretes a lubricating oily matter (sebum) into the hair follicles to lubricate the skin and hair.

Question 16

Name the structure

Answer 16

Lamellated corpuscle

are one of the four major types of mechanoreceptor. They are nerve endings in the skin responsible for sensitivity to vibration and pressure.

Question 17

Name the structure

Answer 17

Tactile (Meissners) corpuscle

Tactile is flat and lamellated has a shape.

tactile provides fine touch, to judge texture including the lips, palms and nipples

Question 18

Name the structure

Answer 18

Medulla

Question 19

Name the structure

Answer 19

Cortex

Provides strength, structure, color and texture

Question 20

Name the structure

Answer 20

Cuticle

Protects the cortex

Question 21

Name the structure

Answer 21

Internal epithelial root sheath

surrounds and protects the growing hair

Question 22

Name the structure

Answer 22

External epithelial root sheath

Question 23

Name the structure

Answer 23

Hair bulb

forms the base of the hair follicle. In the hair bulb, living cells divide and grow to build the hair shaft.

Question 24

Name the structure

Answer 24

Hair papilla

The dermal papilla consists of mesenchymal cells in the hair follicle, which plays the main role in the regulation of hair growth.

Question 25

Name the structure

Answer 25

Arrector pili muscle

Attached hair follicle at one end and to dermal tissue on the other end.

In order to generate heat when the body is cold, the arrector pili muscles contract all at once, causing the hair to “stand up straight” on the skin.

Question 27

Identify the structures

1-6

Answer 27

1. Arrector pili muscle
2. Sebaceous gland
3. External root sheath
4. Dermal papillae
5. Hair bulb
6. Hair follicle