V. Integument Flashcards
What is Integument?
(in-teg ū́ -ment; integumentum = a covering) is the skin that covers your body. Skin is also known as the cutaneous( kū-tā ń ē-ŭs) membrane, orcutaneouslayer.
What does the Integumentary system consist of?
The skin and its derivatives—nails, hair, sweat glands, and sebaceous glands.
What are the 3 main glands?
- Sebaceous (oil)
- Mammary
- ? Sweat
What are the main functions?
Barrier - between external and internal environments
- Protection
- Regulation of Body Fluids
- Regulation of Body Temperature
- Absorptive/ Excretory Functions
- Sensory Reception
- Communication
Protection…(5)
a. Micro-organisms (Film of oil develops from sebaceous glands on the skin which keeps the them under control)
b. water - barrier for both inside and outside
c. chemicals
d. radiation - ultraviolet radiation
e. mechanical trauma (thinker skin (hypo-dermis) thickest layer
Skin makes up ___% of our weight
70%
How many sq ft of skin do humans have on average?
21 sq ft
Regulation of body fluids
Prevents excess water loss
This is the reason why severe burns can be a problem
Regulation of body Temperature (cooling)
Sweating - evaporation from skin causes cooling sensations
circulation - cooling of blood
Regulation of body temperature (warming)
Goose bumps - hair stands up (Arector pili muscle causes it to stand)
In the winter the cooling circulation shuts down - reason why we turn red when we walk inside
Fat - Insulator
Absorptive/ Excretory Functions
- oxygen & carbon dioxide - amphibians use skin for respiration
- fat soluble vitamins (vit D), drugs (Skin patches), toxins (poison Ivy)
- excretion of NaCl, nitrogenous wastes
- ultraviolet light (makes vitamin D3 - needed for calcium and phosphate absorption by intestine)
- D3 deficiency = rickets (kids) or Osteomalacia (adults)
Sensory Reception
Skin is one big sensory organ - there are sensory receptors everywhere
- abundance of receptors varies according to location on body
- nerve endings for temperature, touch, pressure, vibration, pain
- Deep pressure in feet, butt, ect
Communication
Facial expressions Moving Skin Talking Cues - red face/ flush, nervous - sweating mood - animals can detect odor Continuation of humans
Texture
Rough and soft
Thickness
Varies
Soles of feet – thickest part
eyelids/ ear drums very thin
Average skin thickness: 1-2 milliliters
Surface Patterns
- ridges (knuckles, palms of hands, finger prints)
- creases and lines (related to how you move your face, frowning/ smiling)
- tension lines (cuts during surgery are made along these)
- stretch marks (tearing scars)
what are the 3 types of coloration?
- Melanin
- carotene
- hemoglobin
Melanin
melanocytes
natural coloration in skin pigments
same amount in everyone (regardless of skin color)
Carotene
yellow/ orange pigment
Hemoglobin
gives the underline redness color from the blood through circulation under skin.
Bruises - are just broken blood vessels (turn green - yellow when hemoglobin is being broken down)
Gives clues to body conditions… (list 4)
- Disease (blue pigments —> yellow jaundice; red area = infection; rashes spots ect. (measles, chicken pox), allergies
- shock (pale skin)
- cyanosis (blue lips and nails) - anoxia (inadequate oxygen)
- abnormal texture (glandular, nutritional disfunction)
3 main layers…
- Epidermis (from ectoderm)
- Dermis (from mesoderm – dermatome)
- hypodermis (from mesoderm – dermatome) - deepest layer
Epidermis cell types
- Keratinocytes - keratin (define layers of skin)
2. Melanocytes
Epidermis layers (5)
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
Stratum corneum
skin layer 1
looks like cornflakes
strutum lucidum
skin layer 2
strutum granulosum
skin layer 3
strutum spinosum
skin layer 4
main layer
joined by junctions
looks like spines under microscope) - actually desmosomes
strutum basale
skin layer 5
germinativum?
Basal laminate
extra cellular
Skin Cancer
- Basal cell carcinoma
- Squamous cell carcinoma
- melanoma
Basal Cell Carcinoma
Skin Cancer
Doesn’t metastasize
Squamous Cell Carcinoma
Metastasize
Spinosum
Melanoma
Can occur anywhere
Probably already metastasized by the time it is found
occurs by melanoma —?