Integumentary System

Question 1

Function of the skin

Answer 1

The skin has many functions such as:
thermoregulation
pathogen protection
protection against UV rays
energy storage
vitamin D production
mechanical damage protection

Question 2

Epidermis

Answer 2

The top layer of the skin which includes the: stratum cornneum and acidic mantle

Question 3

Stratum Corneum

Answer 3

Made up of 25-30 sub layers of flattened cells that provide protection to the skin and body. These cells are constantly exfoliated by friction and replaced by new cells.

Question 4

Keratinised Stratum Corneum

Answer 4

The stratum corneum are cells are rich in the structural protein keratin to provide protective properties

Question 5

Stratum Basale

Answer 5

Cells found in the deepest epidermis layer that become rounder, flatter and harder before moving to the surface (stratum corneum) to replace the stratum corneum layer

Question 6

Acidic Mantle

Answer 6

Also found on the surface of the skin, and is slightly acidic as it’s the body’s first line of defence against pathogens

Question 7

Dermis

Answer 7

The tough, elastic middle layer of the skin, made up of interlaced (white) fibrous tissue and (yellow) elastic fibres

Question 8

Components of Dermis

Answer 8

blood vessels
lymphatic vessels
sweat glands and ducts
sebaceous glands
Hair follicle and strands
hair erector muscles

Question 9

Hair follicle

Answer 9

A tube like structure (pore) which surrounds the root and strand of hair to provide a pathway for the hair shaft (strand) to grow through.
The white bulb at the base of hair strands is a protein called keratin

Question 10

Hair erector muscle

Answer 10

The muscle contracts (under the influence of the connected nerve) to cause hairs to erect (stand on end)

Question 11

Sebaceous (oil) Gland


Answer 11

A gland which connects to the hair follicle to release sebum to the surface of the skin

Question 12

Sebum

Answer 12

An oily substance produced by the sebaceous gland that:
protects the skin from drying out
lubricates to reduce friction
makes the skin more impervious to moisture

Question 13

Melanin

Answer 13

A natural dark skin pigment that caused the hair, eyes & skin to become pigmented (appear darker). The amount of you have depends on:
genetics
previous ancestral exposure to UV

Question 14

Role of melanin

Answer 14

Absorbs harmful UV rays to protect the skin against cellular damage from UV light exposure. It makes skin appeared ‘tanned’ during the summer a the sun causes melanin to move to the surface of the skin. Eventually fades away as sun is less prevalent during winter.

Question 15

Perspiration


Answer 15

The process of sweating, involving:
sweat glands
duct of sweat glands
sweat pore

Question 16

Sweat glands

Answer 16

A gland in the dermis which produces sweat (a mixture of water and salts) which is carried through the sweat gland duct to the epidermis where it’s released onto the skin through the sweat pore. To reduce body temperature

Question 17

Subcutaneous layer

Answer 17

The deepest layer of the skin (8% thicker in female then male). It connects to underlying organs and is made of:
loose fibrous connective tissue (collagen)
interlaced with blood vessels
fat (adipose tissue)

Question 18

Functions of the subcutaneous layer

Answer 18

The subcutaneous layer (mainly adipose) provides insulation for the body, energy release, stores lipids, cushions the body, used for communication & is important for tissue repair

Question 19

Vitamin D production

Answer 19

The skin absorbs UV rays from the sun to help with the production of UV rays from the sun, which is needed for strong bones and good eyesight

Question 20

Vasodilation & Vasoconstriction


Answer 20

Vasodilation: blood vessels (arterioles) open up and move closer to the skin to increase volume of blood so more heat can be loss by evaporation.
Vasoconstriction: blood vessels (arterioles) constrict and move further from the skin to reduce blood volume flow so less heat escapes

Question 21

Pilorelaxation & Piloerection

Answer 21

Pilorelaxation: hair erector muscle relax so hairs on the surface of the skin flatten
Piloerection: hair erector muscles contract so hairs stand up (goosebumps) to trap a layer of insulating air around the skin

Question 22

High temperatures

Answer 22

High temperatures
Hypothalamus detects high temperatures so sends impulses to the skin to reduce temperature:
Produce sweat (evaporates quickly to reduce temp)
Pilorelaxation
Vasodilation
NO shivering

Question 23

Low temperatures

Answer 23

Hypothalamus detects low temperatures so sends impulses to the skin to increase temperature:
Shivering (rapid contraction to produce heat energy from ATP)
Piloerection
Vasoconstriction
NO sweating