Transcript Skin and Muscles

Chapter 37
What do you think the functions
of the skin are?
Integumentary System
Skin
Hair
Nails
Functions
Protect from injury
Defense against illness
Regulate body temp
Prevents dehydration
Senses environment
Skin
 15% of your
weight
 Largest organ
 Specialized
Structures
 Integumentary
System
Tissues of Skin
Connective
Epithelial
Layers:
 Epidermis
 Dermis
 Subcutaneous
Epidermis
Outermost
layer
Composed of
epithelial cells
Epidermis Continued
 Outermost
layer- flat, dead
cells
 Filled with
Keratin
 Protein that
protects and
waterproofs
Replacement of cells
 Mitosis occurs
frequently
 Outermost cells
scraped away
 New cells made
at the basal layer
Other Cells of the
Epidermis
Melanocytes
Innermost
layer of
epidermis
Form melanin
Pigment
Role of melanin
Skin coloration
Absorbs UV
rays
Dermis
Second layer
Connective
Tissue
 Elasticity
 Toughness
Specialized Cells of Dermis
 Hair follicles
 Nerve Cells
 Blood Vessels
 Sweat Glands
 Sebaceous
glands
 Muscles
Subcutaneous Layer
Below the
dermis
Composed of
connective
tissue (fat)
Functions of Subcutaneous
 Insulation
 Energy Storage
 Absorb Shock
 Varying amount
of subcutaneous
layer
Pacinian Corpuscle
Detects
pressure
changes and
vibrations
Hair
 Specialized
epidermal cells
 Produced by hair
follicle
 Dead cells filled
with keratin
Hair
 Grows for average of
4 years
 Stops for around 3
months
 Falls out
Hair Color
Nails
 Specialized
epidermal cells
 Cells in the cuticle
make
 Newest cells near
cuticle
 Filled with keratin
Skin Disorders
 Acne- overproduction
of sebum
 Clogs pores
 Causes area to be
infected, inflamed
and pus filled
Skin Cancer
 Mutations to cells by
overexposure to UV
rays
 Carcinoma and
melanoma
 Carcinoma= nonpigmented cells
Melanoma
 Cancer of
melanocytes
 More dangerous
 metastasized
Function of Muscles
Maintain
posture
Generate heat
Stabilizes
joints
Produce
movement
Muscle Tissue
Skeletal
Smooth
Cardiac
Skeletal Tissue
• Voluntary
• Multi-
nucleated
• Striated
• Attached to
skeleton
• Biceps
Smooth Muscle
Involuntary
One nucleus
per cell
Not striated
Lines organs
Cardiac Muscle
Involuntary
Striated
Uni-nucleated
Heart
Muscle attachment
Tendon
Insertion
Origin
Muscle Pairs
Antagonistic
Flexor
Extensor
Exercise
 ATP made by
aerobic cellular
respiration
 Needs Oxygen
 Occurs in
mitochondria
Aerobic Respiration
C6H12O6 + 6O2→ 6H2O + 6CO2 +
ATP
 Intense Exercise?
Glycolysis
Used to produce ATP when oxygen levels
reduce
Also called anaerobic respiration
Takes place in cytoplasm
Lack of ATP- break down fat and
glycogen
Muscle Fatigue
Muscle unable to generate force
Caused by:
More ATP is needed than can be produced
Fitness
Aerobic
Exercise
Increases
efficiency of
the Heart
Resistance Training
Increases size
of muscle
fibers