Transcript Starr & Taggart Chapter 38 PowerPoint

Protection, Support,
and Movement
Starr/Taggart’s
Biology:
The Unity and Diversity of Life,
Chapter 38
9e
Key Concepts:
Nearly all animals have an integument, a
skeleton, and muscles
Skin protects the body from environmental
insults
The categories of skeletal systems include
hydrostatic skeletons, exoskeletons, and
endoskeletons
Bones function in movement, support, and
protection
Key Concepts:
Blood cells form in bones
Muscles move body parts by contractions
Smooth muscle and cardiac muscle are
responsible for the motions of internal
organs
The sarcomere is the basic unit of
contractions within muscle cells
Integumentary System
Cuticle
Roundworms
Insects
Arthropods
Vertebrates
Skin
Epidermis
Dermis
Structures Derived from Skin
Hair
Nails
Feathers
Human Skin
Epidermis
Stratified
epithelium
Keratinocytes
Keratin
Melanocytes
Melanin
Glands
Sweat
Sympathetic
system control
Palms, soles,
forehead,
armpits
Oil
Lubricate
Types of Skeletons
Hydrostatic
Invertebrates
Sea anemone
Earthworm
Exoskeleton
Shells
Arthropods
• Hinge joints
• Muscle
attachments
Types of Skeletons
Endoskeleton
Vertebrates
Most animals
Bones
Sharks
Cartilage
Shark, Reptile, & Mammal
Functions of Bones
Movement
Protection
Support
Mineral storage
Blood cell formation
Bone Structure
Shapes
Long
Short
Irregular
Calcium hardened
Collagen fibers
Ground Substance
Types
Compact
Haversian
System
Spongy
Red and Yellow
Marrow
Bone Structure
Bone Formation
Cells
Osteoblasts
Osteoclasts
Osteocytes
Tissue turnover
Development
from cartilage
Human Skeleton System
Appendicular
Axial
Pectoral girdle
Skull
Arm, hand
bones
12 Pairs of Ribs
Pelvic girdle
26 Vertebrae
Leg, foot bones
Intervertebral
disks
Breastbone
Skeletal Joints
Between bones
Types
Fibrous
Cartilaginous
Synovial
Ligaments
Bone to bone
Tendons
Muscle to bones
Skeletal - Muscular Systems
Tendon sheath
Functional Organization
of Muscle
Muscle bundle
Myofibril
Sarcomere
Unit of
contraction
Filaments
• Thin
(Actin)
• Thick
(Myosin)
Sliding Filament
Model of Contraction
Pulling interactions among filaments in
sarcomere
Actin filaments extend from Z lines
Myosin filaments overlaps part of Actin
Muscle contraction
Cross-bridge formation
Myosin pulls actin toward the center of the
sarcomere
Sliding Filament
Model of Contraction
Before Contraction
Z
Z
After Contraction
Z
Length of sarcomere shortens with contraction
but filament length is unchanged
Myosin
Actin
Z
Control of Muscle Contraction
Signal from motor neuron causes action
potential in muscle cell
Calcium ions released from sarcoplasmic
reticulum
Actin and myosin filaments interact to bring
about contraction
The Control Mechanism
Troponin
Tropomyosin
Actin
Calcium binds to
troponin exposing
myosin binding
sites
Sources of Energy for
Contraction
Properties of Whole Muscles
Muscle Tension
Mechanical force a contracting muscle exerts
on an object
Contractions
Isometric
Isotonic
Lengthening
Properties of Whole Muscles
Motor unit
Motor neuron
All muscle cells that form junctions with
its endings
Muscle response
Twitch
Tetanus
Fatigue
Muscle Contraction
Aerobic Exercise and
Strength Training
Aerobic
Not Intense
Long duration
Increase in number of mitochondria
Increase energy production
Improve endurance
Strength
Weightlifting
Glycolysis
In Conclusion
 Most animals have an integumentary
system which may include a cuticle or skin
 Skin protects against environmental injury
and has sensory receptors
 Skin consists of layers of dead keratinized
and melanin-shielded epithelial cells
 Skin consists of two regions: epidermis and
dermis
In Conclusion
 The epidermis consists of layers of dead
keratinized and melanin-shielded epithelial
cells
 The dermis contains glands
 Contractile cells move animal parts
 There are three types of skeletons:
hydrostatic, exoskeleton, and
endoskeleton
In Conclusion
 Bones are mineralized and function in
protection, and support of body parts
 The human skeleton is divided into
appendicular and axial portions
 Skeletal joints are areas found between
bones
In Conclusion
 Cells of smooth, cardiac, and skeletal
muscle contract in response to adequate
stimulation
 Tendons attach muscle to bones
 The sarcomere is the basic unit of
contraction in a muscle cell
In Conclusion
 The sliding-filament model explains how
myosin pulls actin towards the middle of
the sarcomere
 There are 3 metabolic pathways for ATP
production for muscle cells
 A motor unit is a motor neuron and muscle
cells that form junctions with its endings

developed by M. Roig