Lecture 10 - Integumentary and Lymphatic Systems Flashcards
Name the three main layers of the skin
1 - Epidermis
2 - Dermis
3 - Subcutaneous layer (protective adipose tissue)
True or false:
The epidermis contains ample blood vessels and nerve endings
False
What kind of cells make up the epidermis and in which proportions?
90% Kerinatocytes: a tough fibrous protein that protects from heat, microbes and chemicals
8% Melanocytes: a pigment that contributes to skin colour and absorbs UV light. Two types: eumelanin = brown/black; pheomelanin = reddish/yellow
2% Langerhans cells: immune cells (skin’s surveillance)
What are the two types of melanin in the skin and how are they different?
Eumelanin = brown/black
Pheomelanin = reddish/yellow
Name three accessory structures in the dermis
Sweat glands
Hairs
Sebaceous glands
Nerve endings
In relation to the epidermis, what do the following definitions refer to?
a. A single row of dividing to form new keratinocytes
b. 3-5 layers of cells undergoing apoptosis
c. 25-30 layers of flattened dead keratinocytes
a. Stratum basale
b. Stratum granulosum
c. Stratum corneum
Describe the function of the following components of the dermis:
a. Collagen fibres
b. Elastic fibres
a. Tensile strength
b. Stretch and recoil
Which cells are responsible for the production of collagen and elastic fibres?
Fibroblasts
Which of the following components are located within the dermis?
a. Lymph vessels
b. Sweat glands
c. Sensory nerve endings
d. Stratum corneum
e. Hairs
f. Sebaceous glands
g. Arterioles and veins
h. Fibroblasts and immune cells
i. Freckles
a. Lymph vessels
b. Sweat glands
c. Sensory nerve endings
e. Hairs
f. Sebaceous glands
g. Arterioles and veins
What is the function of Meissner’s corpuscle?
Detection of light pressure
Name two body locations that contain numerous sweat glands (4)
Palms of hands
groin
axillae (armpits)
soles of feet
Name four functions of sebaceous glands
It secretes sebum that
1. Forms a protective barrier
2. Keeps hair and skin soft
3. Waterproofing
4. Anti-microbial
List four functions of the skin
1- Protection
2- Thermoregulation
3- Vitamin D production
4- Sensation
What is the range that is considered normal body temperature?
36.5 - 37.5 degrees
Name three body locations containing sebaceous glands.
Face, lips, scalp, nipples, glans penis
Explain specifically how sebum can act as an anti-microbial
The fatty acids in sebum inhibit bacterial growth
Describe the function of the arrector pili muscle
The arrector pili connects the hair follicle to the dermis.
When the hair is erect, it traps a layer of air next to the skin (part of thermoregulation)
Explain how age can affect sebaceous gland activity
Activity increases in puberty, and decreases with age
Describe THREE ways in which the skin provides protection
1- Physical barrier — closely-packed keratinised cells and melanin.
2- Sebum — contains fatty acids which inhibit microbial growth.
3- Sweat — contains lysozymes, which are enzymes that break down bacteria.
4- Desquamation — shedding of skin cells helps remove microbes.
5- Nerve sensors — induce protective reflexes.
Name TWO temperature control centres
Temperature control centres are the
hypothalamus and medulla oblongata
(brain stem)
Name the nervous system that controls both sweat gland and blood vessels in thermoregulation
Autonomic nervous system (ANS)
Describe the main difference between ‘hypothermia’ and ‘hyperthermia’
Hypothermia (<35°C) - When core temperature drops below that required for normal metabolism and body functions.
Hyperthermia (>38.5°C ) - When core temperature elevates above 38.5°C.
Which body organ is responsible for producing active vitamin D?
The kidneys
Name TWO minerals that vitamin D promotes uptake from the gastrointestinal tract.
Calcium and phosphorus