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
Basic types of bones
long short flat irregular sesamoid
long bone
compact
short bone
spongy except surface
flat bone
plates of compact bone enclosing spongy bone
irregular bone
variable
sesamoid bone
developed in tendons or ligaments
ends of bone
epiphyses
shaft of bone
diaphysis
ara white fibrous membrane
periosteum
ticular cartilige
caps the end of bone
bone matrix
strong, hard, durable, tough material
Bone matrix composition
collagen type 1 fibres (strong, rope like protein fibres) and crystals (surrounding the collagen fibres)
Bone cells
Osteogenic
Osteoblasts
Osteocytes
Osteoclasts
Osteogenic cells
Stem cells, the young cells that develop into other specialised cells
Oestoblasts
Matrix synthesising cell
Bone growth
Outside of Bone matrix
Oestoclasts
Bone reabsorbing cell
Bone eaters
Outside of cell
Osteocytes
Mature bone cell
Monitors and maintains bone matrix
Inside bone
Bone tissue
Dynamic, always changing
Lacuna
Cavities which the oestocytes are in
Long bone - compact bone
Solid, dense bone
Basic unit of structure is osteons
Osteons
Ring circles of bone crystal
Long bone - spongy bone
Sponge like with spaces and trabeculae
No osteon
Usually ends of bone
Trabeculae
Bony struts surrounded by bone marrow
When trabeculae are formed
Formed after birth, formed in places that need added strength and to lessen force
Flat bone - structure
Compact bone
Spongy bone
Compact bone
Osteons- structure
Central cavity - arteries and veins
Lacuna - cavatites that hold osteocytes
Canliculi - allows nutrients from arteries to fuse to other osteocytes
Collagen fibres
Winded up bone
Tough fibres
Run in different directions in each layer of bone to provide strength
Thyroid gland
Secretes calcitonin
Inhibits osteoclasts activity
Decreases blood calcium levels
Parathyroid gland
4 small glands
Secretes parathyroid hormone
Stimulates osteocytes activity and bone degradation
Increases blood calcium level
Growth hormone
Secreted in parathyroid
Stimulates oestoblasts and osteoclasts
Sex hormones
Oestrogen and testosterone inhibits oestoclast activity
Stimulates osteoblasts activity
Epiphyseal plate
Cartilage growth plate
At 18 cartilage stops dividing to let in more bone and bone replaces it
Red bone marrow
Found in spongy bone
Site of blood cell production
Yellow marrow
Oily substance
Found in meduallary cavity of long bones (middle cavity)
Site of fat storage
Cartilage
Made of Chondrocytes (found in lacuna) Matrix consisting of - collagen fibres ( strength) - elastin fibres (flexibility) - chondrotin sulphate
Chondrotin sulphate
Chemical that attracts water
Causes cartilage to be stiff - filled with water
Hyaline cartilage
Most abundant but weakest
Rubbery
No blood vessels or nerves so repair is slow
Found in joints
Provides support, flexibility and reduces friction
Elastic cartilage
Networkof elastic fibres - maintains shape
Provides elasticity and shape
Fibrocartilage
Visible collagen fibres - causes rigidity and strength as well as support and flexibility
Absorbs shock, resists compression
Cranium
Skull
Mandible
Chin
Clavicle
Shoulder bones
Scapula
Bone inbetween shoulder and torso
Humerus
Top of arm
Sternum
Middle of chest
Ilium
Pelvic bones
Sacrum
Where spine mets pelvis
Carpals
Wrist
Metacarpals
Bottoms of fingers
Plalanges
Top of fingers
Radius
Outer bone of lower arm
Ulna
Inner bone of lower arm
Femur
Top of leg
Patella
Knee cap
Ishchium
Pubis bone
Fibula
Outer lower leg
Tibia
Inner lower leg
Tarsals
Ankle
Metatarsals
Bottom of foot Close to ankle