chapter 37. what do you think the functions of the skin are?
TRANSCRIPT
Chapter 37
What do you think the functions of the skin are?
Integumentary SystemSkin HairNails
FunctionsProtect from injuryDefense against illnessRegulate body tempPrevents dehydrationSenses environment
Skin15% of your weight
Largest organSpecialized Structures
Integumentary System
Tissues of SkinConnectiveEpithelialLayers:
EpidermisDermisSubcutaneous
EpidermisOutermost layer
Composed of epithelial cells
Epidermis ContinuedOutermost layer- flat, dead cells
Filled with Keratin
Protein that protects and waterproofs
Replacement of cellsMitosis occurs frequently
Outermost cells scraped away
New cells made at the basal layer
Other Cells of the EpidermisMelanocytesInnermost layer of epidermis
Form melanin
Pigment
Role of melaninSkin coloration
Absorbs UV rays
DermisSecond layer
Connective TissueElasticityToughness
Specialized Cells of DermisHair folliclesNerve CellsBlood VesselsSweat GlandsSebaceous glands
Muscles
Subcutaneous LayerBelow the dermis
Composed of connective tissue (fat)
Functions of SubcutaneousInsulationEnergy StorageAbsorb ShockVarying amount of subcutaneous layer
Pacinian CorpuscleDetects pressure changes and vibrations
HairSpecialized epidermal cells
Produced by hair follicle
Dead cells filled with keratin
HairGrows for
average of 4 yearsStops for around
3 monthsFalls out
NailsSpecialized
epidermal cellsCells in the
cuticle makeNewest cells near
cuticleFilled with
keratin
Skin DisordersAcne-
overproduction of sebum
Clogs poresCauses area to be
infected, inflamed and pus filled
Skin CancerMutations to cells
by overexposure to UV rays
Carcinoma and melanoma
Carcinoma= non-pigmented cells
MelanomaCancer of
melanocytesMore dangerousmetastasized
Function of MusclesMaintain posture
Generate heat
Stabilizes joints
Produce movement
Muscle TissueSkeletalSmoothCardiac
Skeletal Tissue•Voluntary•Multi-nucleated•Striated•Attached to skeleton•Biceps
Smooth MuscleInvoluntaryOne nucleus per cell
Not striatedLines organs
Cardiac MuscleInvoluntaryStriated Uni-nucleated
Heart
Muscle attachmentTendonInsertionOrigin
Muscle PairsAntagonistic
FlexorExtensor
ExerciseATP made by aerobic cellular respiration
Needs OxygenOccurs in mitochondria
Aerobic RespirationC6H12O6 + 6O2→ 6H2O + 6CO2 + ATP
Intense Exercise?
GlycolysisUsed to produce ATP when oxygen levels reduce
Also called anaerobic respirationTakes place in cytoplasmLack of ATP- break down fat and glycogen
Muscle FatigueMuscle unable to generate forceCaused by:More ATP is needed than can be produced
FitnessAerobic Exercise
Increases efficiency of the Heart
Resistance TrainingIncreases size of muscle fibers
