lecture 1 - skin histology

Question 1

What are the 3 key layers of the skin?

Answer 1

Epidermis, dermis, hypodermis

Question 2

What are the 4 key functions of the skin?

Answer 2

Protective, biomechanical synthesis, temperature homeostasis, sensation

Question 3

What type of tissue makes up the epidermis?

Answer 3

Stratified epithelium

Question 4

What is the predominant cell in the epidermis?

Answer 4

Keratinocytes

Question 5

What is the function of langerhans cells in the skin?

Answer 5

Immune function

Question 6

What is the function of merkel cells in the epidermis?

Answer 6

Sensory nerve endings

Question 7

What is the function of melanocytes in the epidermis?

Answer 7

Produce melanin pigment

Question 8

What are the 5 layers of the epidermis?

Answer 8

Superficial to deep: stratum corneum, stratum lucidum (thick skin only), stratum granulosum, stratum spinosum, stratum basale

Question 9

What is the main function of the stratum basale?

Answer 9

epidermal cellular proliferation via keratinocyte stem cells.

Question 10

What does the stratum basale sit on that seperates the epidermis from the dermis?

Answer 10

Basement membrane

Question 11

What is the name for the protrusions of the epidermis into the dermis?

Answer 11

Epidermal/Rete pegs

Question 12

What is the name for the protrusions of the dermis into the epidermis?

Answer 12

Dermal papillae

Question 13

What are the 2 components of the basal lamina of the dermal-epidermal junction?

Answer 13

lamina lucida, lamina densa

Question 14

What do the basal keratinocytes of the epidermis contain?

Answer 14

Melanosomes, keratin tonofilaments

Question 15

What connects keratinocytes together in the epidermis?

Answer 15

Desmosomes

Question 16

What connect basal keratinocytes to the basal lamina?

Answer 16

Hemidesmosomes

Question 17

What is the function of desmosomes in the epidermis?

Answer 17

Connects keratinocytes together to provide tensile strength

Question 18

What is the shape of cells in the stratum granulosum?

Answer 18

Flattened

Question 19

What feature of the stratum granulosum helps to form the water barrier of the skin?

Answer 19

Keratocyte hyaline granules - produce hydrophobic glycophospholipids

Question 20

What substance is found in large amounts amongst the cells in the stratum corneum?

Answer 20

Keratin

Question 21

How are melanocytes adhered within the epidermis?

Answer 21

Adhered to the basal lamni via hemidesmosomes, but not to other cells in the epidermis via desmosomes.

Question 22

Where are melanosomes found within the epidermis?

Answer 22

The stratum granulosum

Question 23

What are the 3 key components of the dermis?

Answer 23

Connective tissue, meshwork of fibres (collagen & elastin), ground substance

Question 24

What is the function of collagen in the dermis?

Answer 24

Tensile strength

Question 25

What is the function of elastin in the dermis?

Answer 25

elasticity - stretch & recoil

Question 26

What types of cells are found in the dermis/

Answer 26

Fibroblasts, plasma cells, macrophages, glands

Question 27

What are the 2 regions of the Dermis?

Answer 27

Papillary, Reticular

Question 28

What is the most superficial layer of the dermis?

Answer 28

Papillary layer

Question 29

What is the deep layer of the dermis?

Answer 29

Reticular layer

Question 30

Which layer of the dermis sits adjacent to the epidermis?

Answer 30

Papillary layer

Question 31

Which layer of the dermis sits adjacent to the hypodermis?

Answer 31

Reticular layer

Question 32

What type of receptor is found in the papillary layer of the dermis?

Answer 32

Meissner’s corpuscles

Question 33

What type of receptor is found in the reticular layer of the dermis?

Answer 33

Pacinian corpuscles

Question 34

What is the key tissue type of the hpodermis?

Answer 34

Connective tissue (adipose tissue)

Question 35

What is the function of the adipose tissue of the hypodermis?

Answer 35

Thermal insulation, shock absorption, metabolic energy storage

Question 36

What are the 3 key accessory structures of the skin?

Answer 36

Hair, sebaceous glands, sweat glands

Question 37

What muscle moves hair follicles?

Answer 37

Arrector pilli muscle

Question 38

What layer of skin does a hair follicle sit in?

Answer 38

In the epidermis, which extends down into the dermis around the follicle.

Question 39

Where do sebaceous glands typically open into?

Answer 39

Hair follicles

Question 40

What do sebaceous glands secrete, and what is its function?

Answer 40

Sebum - produces an epidermal barrier

Question 41

What are the 2 types of sweat gland?

Answer 41

Eccrine, apocrine

Question 42

Which type of sweat gland are present everywhere in the body?

Answer 42

Eccrine, apocrine are not everywhere

Question 43

Where do apocrine sweat glands open into?

Answer 43

Hair follicles

Question 44

Where do eccrine sweat glands open into?

Answer 44

The skin’s surface

Question 45

What structure helps to push sebum out into hair follicles?

Answer 45

Arrector pili muscle

Question 46

What are the 2 parts of a sweat gland?

Answer 46

Secretory region, duct

Question 47

What do the sensory receptors in the skin detect?

Answer 47

touch, pressure, temperature, pain

Question 48

Where are Meissner’s corpuscles found?

Answer 48

Dermal papillae (papillary layer)

Question 49

What are pacinian corpuscles sensitive to?

Answer 49

Pressure & vibration - mechanoreceptors

Question 50

What is the structure of a pacinian corpuscle?

Answer 50

Capsule, intermediate layered zone, central core with axon terminal