Lecture 20 - Integumental System

Question 0

What are some general roles of skin

Answer 0

Sensation
Thermoregulation
Vitamin D absorption
Protection

Question 1

What are skin appendages?

Answer 1

Nails
Hair
Breasts

Question 2

What is the germ layer derivate of the skin?

Answer 2

Epidermis: ectoderm
Dermis: mesoderm

Question 3

What is the epidermis made up of?

Answer 3

Keratin
Basal cells
Melanocytes

Question 4

Describe the layers in the skin

Answer 4

Epidermis
Dermis
Subcutaneous tissue
Deep fascia
(Muscle
Bone)

Question 5

What is subcutaneous tissue made up of?

Answer 5

Fat

Fibrous strands

Question 6

Describe subcutaneous fat distribution in males and females

Answer 6

Males: thighs, belly
Females: bottom, thighs, breasts, belly, back of neck

Question 7

What is meant by ‘thick skin’, and what are the features?

Answer 7

This is the thick, hairless skin on the palms and soles of feet

Question 8

What is the simian crease associated with?

Answer 8

Foetal alcohol syndrome

Downs’ syndrome

Question 9

What is a general rule for skin surafce area percentages?

Answer 9

Rule of 9s
Trunk: 18%
Leg: 9% each
Arms: 9%
Head: 9%
Genitalia: 1%

Question 10

Why are skin tension lines important?

Answer 10

Scar will heal and appear better is the laceration is made across the skin tension line

Question 11

Why is skin surface area important for burns victims?

Answer 11

The fluid loss and replacement is proportional to percentage of skin lost

Question 12

What is the name of the hair + sebum gland?
Describe the structure of it

Where is it located?

Answer 12

Pilosebaceous gland

Hair and hair follicle attached to Arrector pilus muscle
Sebaceous gland further up the shaft of the hair

The hair follicle is in the dermis, and it extends out through the epidermis through the skin

Question 13

Where is a sweat gland located?

Answer 13

In dermis, up our of the epidermis

Question 14

What is the structure of the sweat gland?

Answer 14

Gland (dermis)

Duct

Question 15

What is interesting, evolutionarily, about the finger nail?

Answer 15

It has migrated from the anterior to the posterior asspect

Question 16

What is the special region in the mouth?

Answer 16

Mucocuaneous junction

Mucosa meets the skin

Question 17

What is the structure of the nail bed?

Answer 17

Deep connective tissue

Question 18

Describe the blood and nerve supply of the skin

Answer 18

Epidermis: avascular and aneural
Dermis: rich vascular and nervous innervation

Question 19

Which receptors are present in the skin?

Answer 19

Mechanoreceptors: Meissner, Merkel, Pacini, Ruffini

Nociceptors

Question 20

What are the different types of motor innervation of the skin?

Answer 20

Vasomotor: diameter of blood vessels
Sudomotor: sweat glands
Pilomotor: Arrector pili muscle

Question 21

What are the names of the many regions of the skin that have sensory innervation? Give a precise definition

Answer 21

Dermatomes

A region of the skin innervated by a single segment of the spinal cord

Question 22

Describe the pattern of the dermatomes of the body

Answer 22

Since we have limbs, the dermatomes have been pulled out onto the limb, and thus do not proceed directly down the trunk

Arm: C5-8 and T1-2 out along preaxial border, and back along postaxial border

Question 23

Do dermatomes overlap?

Answer 23

Dermatomes do not overlap over the axis

However, they do overlap with adjacent dermatomes

Question 24

Describe the overlapping of mechanoreceptors and nociceptors in dermatomes

Answer 24

The nociceptors overlap much more than the mechanoreceptors.

This ensures that when a dermatome is lost, nociception in that area will not be completely lost

Question 25

Why is shingles interesting when looking at dermatomes?

Answer 25

The virus remains latent in the posterior root ganglion and then reawakens when the individual is immunosuppressed.

It comes down the nerve and produces symptoms only in the dermatome supplied by that posterior root ganglion.

Question 26

Describe the regions of blood supply to the skin

Answer 26

The body is made up of angiosomes: regions that are supplied by a single artery and vein