Transcript Protection, Support & Movement

Protection, Support & Movement
Jeweled Joints
In The News
Movement in Humans
• Primarily from muscle moving bones
• Skin stretches to accommodate movement
• Body uses chemical energy (ATP) to move
muscle filaments
Animal Skeletons & Movement
• Hydroskeleton
– Support system using fluid under pressure
– Muscles attached to flexible body wall
– Example: worms
Animal Skeletons & Movement
• Endoskeleton of hard plates
– Found in echinoderms
– Movement is by hydraulics
Animal Skeletons & Movement
• Exoskeleton
• Found in arthropods
• Muscles attach to external skeleton
Animal Skeletons & Movement
• Endoskeleton
– Muscles attached to bones
– Found in all vertebrates
Bone
• Type of connective tissue
– Cells
– Matrix of collagen & mineral salts in a
semisolid gel
Bone
• Types of bone
– Compact
• Concentric ring structure
• Cavity filled with yellow bone marrow
– Spongy
• Latticework of thin plates
• Filled with red bone marrow
Bone Structure
Bone Function
• Support the body
• Protect internal structures
• Store minerals
• Produce blood cells
• Aid in movement
Human Skeleton
• Axial skeleton & appendicular skeleton
Axial Skeleton-80 bones
• Skull
– 8 cranial bones
– 14 facial bones
• Vertebral column
– 26 vertebrae
• Rib cage
– 12 pair of ribs
• Hyoid bone
Appendicular Skeleton-126 bones
• Appendages
• Pectoral girdle
• Pelvic girdle
Ligaments
• Dense connective tissue
• Attaches bone to bone
Tendons
• Cords of dense connective tissue
• Attach muscles to bones
Joints
• Articulation
• Place where bones meet
• Different joints allow different movements
Synovial (freely movable) Joint
Bone & Joint Health
• Moderate exercise enhances health
• Calcium helps maintain bone density
Bone & Joint Conditions
• Osteoporosis
– Bones lose mineral density
– Creates fragile bones
• Osteoarthritis
– Cartilage covers articulating ends of bones
– Makes movement painful
Muscles
• Attach to bones by tendons
• Move body parts by contracting
Muscle Attachments
• Origin - attachment to stationary bone
• Insertion – attachment to moveable bone
Muscle Structure
• Orderly arrangement of filaments
– Actin & Myosin
Sarcomere
• Contractile unit of muscles
• As filaments move past each other,
muscles shorten (contract)
Muscle Movement
• Forcefulness, speed, & degree of contraction
depend on the number of contracting muscle fibers
Integument
• Outer covering
• Protects underlying structures
• Barrier to infection
• Conserves water loss
Types of Animal Integument
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Layer of epidermal cells
Cuticle covering epidermal cells
Shell
Chitin cuticle
Thin prickly epidermis
Keratinized skin
Animal Integuments
Animal Integuments
Animal Integuments
Animal Integuments
Animal Integuments
Animal Integuments
Layers of Human Skin
• Epidermis, dermis, & hypodermis
Functions of Human Skin
• Protective barrier against microorganisms, water-loss,
and damaging UV radiation (melanin)
• Sensory surface for pressure, pain, heat, & cold
• Compensates for body movement
• Helps control body temperature- (vasoconstriction and
and vasodilatation), sweat glands
• Manufactures vitamin D in the presence of
sunlight, this vitamin helps body retain calcium
Integumentary System
• Hair, nails, & skin
Skin Development
• Cells produced deep in skin rise to surface
• Keratin is added to cells
• Cells are dead by the time they reach the
topmost layers
• Dead cells are lost at the surface
End chapter 34