Module 2 - Topic 1-2: Integumentary system Flashcards
Basic function of integumentary system
- physical and chemical barrier
- maintains body temp
- enables body to sense environment
- vitamin D synthesis
How blood recieves oxygen
by diffusion through the skin (1-2%)
integumentary makeup
many layers thick
specialised nerve endings
Epidermis
outer layer of squamous epithelium
Dermis
connective tissue, glands, blood and lymph vessels and nervous tissue
Hypodermis
below the dermis, adipose tissue and connective tissue
Keratinocytes
contains fibrous intermediate filaments protein (keratin) and waterproofs
Melanocytes
secretes pigment - melanin
- shields the DNA from UV rays
- close to blood vessels
- delivers melanin granules to kertainocytes
Langerhan’s cells
for immune surveillance and present antigens to immune system
Stratum Corneum
outermost layer, dead, flattened sloughing cells
Stratum Lucidum
clear layer, mainly thick skin
Stratum Granulosom
granular layer, keratohyaline granules
Stratum spinosum
spiny layer, developed desomomes, melanin
Stratum Basale
innermost base, where the live cells, closest to the dermis
Eumelanin
dark, makes skin darker
Phaeomelanin
makes red hair
Carotene
yellow
Haemoglobin
reddish colour
Dermis
highly vascularised
- supplies nutrients and O2 to stratum basale
- involved in temperature regulation
- protects underlying tissues
Ceruminous Glands
modified apocrine glands
- secretes cerumen - wax
Mammary Glands
modified apocrine sweat glands
- secrete milk
Sebaceous glands
associated with hair follicles
- secrete sebum
- oil lubricates hair
Hair
composed of concentric rings of keratinised cells
Eumelanin
gives black brown and blonde colour
Lanugo
loses 2 months before birth
Vellus
fine, pale body hair
Terminal hair
scalp, eyebrow, lashes, axilla, pubis
Around hair follicles
nervous tissue
- microscopic muscle tissue
- contraction forces sebum out of hair follicles
Free nerve endings
pain and temp
merkel discs
light touch and pressure
Ruffini corpuscles
skin distortion and pressure
Meissner’s corpuscles
light touch, texture
Pacinian Corpuscles
deep pressure, tickle and vibration
Hypodermis
consists of adipose tissue
storage depot for triglycerides
protects and insulates underlying skin
Human Skeleton
Compromised bone and cartilage
- provides support and protection
- assists movement
- calcium and phosphate storage
- blood cell production
Bone - qualities
strong and light but prone to wear and tear
Cartilage - qualities
more durable and flexible material
3 types of cartilage
hyaline
elastic
fibrocartilage