1. Biology, 9th ed, Sylvia Mader
Chapter 41
Chapter 41
Locomotion and Support Systems
Locomotion and Support Systems

2. Diversity of Skeletons
Outline
Diversity of Skeletons
Hydrostatic Skeleton
Exoskeletons
Endoskeletons
Human Skeletal System
Axial Skeleton
Appendicular Skeleton
Human Muscular System
The Muscles
Muscle Contraction

3. Hydrostatic Skeleton Functions Source Supports body form
Provides resistance for the contraction of muscles to act against
Source
Some organisms use their fluid-filled gastrovascular cavity
Others use their fluid-filled coelom

4. Locomotion in an Earthworm

5. Exoskeletons and Endoskeletons
Exoskeleton - External Skeleton
Molluscs - composed of calcium carbonate
Arthropods - composed of chitin
Endoskeleton - Internal Skeleton
Echinoderms and vertebrates
Mineralized bone and cartilage
Grows as the animal grows
Does not limit space for internal organs
Supports greater weight

6. Exoskeleton

7. The Vertebrate Endoskeleton

8. Bones store calcium and phosphate ions
Human Skeletal System
Functions
Supports and protects the body
Permits movement
Provides resistive foundation for muscles to act against
Bones store calcium and phosphate ions
Certain bones produce red blood cells

9. Bone Growth and Renewal
Cartilage structures in early development act as models for future bones
Calcium salts deposited in matrix by cartilage cells and later by osteoblasts
Endochondral ossification
Osteoclasts
Break down bone
Remove worn cells
Deposit calcium in the blood
Work with osteoblasts to heal broken bones

10. Anatomy of a Long Bone Gross Details Main shank Spongy bone at ends
Thick outer cylinder of compact bone
Medullary cavity in center
Spongy bone at ends
Details
Compact bone
Unit of structure called osteon
Concentric lamellae arranged around central canal
Osteocytes lie in lacunae at lamellar boundaries
Spongy bone
Numerous bars and plates separated by irregular spaces
Spaces filled with red bone marrow

11. Anatomy of a Long Bone

12. The Human Skeleton

13. Lies in the midline of the body Consists of
The Axial Skeleton
Lies in the midline of the body
Consists of
The skull
The vertebral column
The sternum, and
The ribs

14. Formed by cranium and facial bones
The Skull
Formed by cranium and facial bones
Major bones are named after
The lobes of the brain, and
The facial bones
Foramen magnum
Opening at base of skull
Where spinal cord connects to brain
Bones of cranium surround sinuses

15. The Skull

16. Segments (from superior to inferior)
Vertebral Column
Vertebral column
Supports the head and trunk
Protects the spinal cord and roots of spinal nerves
Segments (from superior to inferior)
Cervical - Neck
Thoracic - Thorax
Lumbar - Small of back
Sacral - Sacrum
Coccyx - Tailbone
Intervertebral disks of fibrocartilage act as padding

17. Protects the heart and lungs, and assists breathing
Rib Cage
Protects the heart and lungs, and assists breathing
Support by the thoracic vertebrae
Twelve pairs of ribs
True ribs
Connect directly to sternum
Seven pairs
“False” ribs
Do not connect directly to sternum
Five pairs

18. The Rib Cage

19. The Appendicular Skeleton
Consists of
The bones within the pectoral and pelvic girdles
The attached limbs
Pectoral girdle – Bones of the shoulder
Anterior
Supports the arms and hands
Pelvic girdle - Bones of the pelvis
Posterior
Supports the legs and feet

20. Bones of the Pectoral Girdle, the Arm, and the Hand

21. Bones of the Pelvic Girdle, the leg, and the Foot

22. Classification of Joints
Fibrous Joints
Immovable
Between cranial bones
Cartilaginous Joints
Slightly Movable
Between vertebrae
Synovial Joints
Freely Movable
Bones separated by a cavity
Ligaments bind bones together at joint

23. The Knee Joint

24. Human Muscular System Skeletal muscles
Attached to the skeleton by cable-like fibrous connective tissue called tendons
Arranged in antagonistic pairs
Can only contract, cannot push
When one muscle contracts, it stretches its antagonistic partner
A muscle at “rest” exhibits tone (minimal contraction)
A muscle in tetany is at maximum sustained contraction

25. Human Musculature

26. Antagonistic Muscles

27. Microscopic Anatomy and Physiology
Sarcolemma
Plasma membrane
Sarcoplasmic Reticulum
Modified endoplasmic reticulum
Myofibrils
Contractile structures in sarcoplasm
Sarcomeres
Units of contraction
Consist primarily of proteins
Myosin
Actin

28. Skeletal Muscle Fiber Structure and Function

29. Sliding Filament Model
Actin filaments at both ends of sarcomere
One end of each filament attached to a Z-plate at one end of the sarcomere
Other end suspended in sarcoplasm
Myosin filaments suspended in between Z-plates
Myosin filaments contain cross-bridges which pull the actin filaments inward
Causes Z-plates to move toward each other
Shortens sarcomere
Sarcomeres stacked together in series and cause myofiber to shorten
Working muscles require ATP
Myosin breaks down ATP
Sustained exercise
Requires cellular respiration
Regenerates ATP

30. Neuromuscular junction
Muscle Innervation
Neuromuscular junction
The synaptic contact between a nerve fiber and a muscle fiber
Nerve impulses bring about the release of a neurotransmitter that cross the synaptic cleft
Signals the muscle fiber to contract

31. Neuromuscular Junction

32. The Role of Calcium and Myosin in Muscle Contraction

33. Diversity of Skeletons
Review
Diversity of Skeletons
Hydrostatic Skeleton
Exoskeletons
Endoskeletons
Human Skeletal System
Axial Skeleton
Appendicular Skeleton
Human Muscular System
The Muscles
Muscle Contraction

34. Biology, 9th ed, Sylvia Mader
Chapter 41
Ending Slide Chapter 41
Locomotion and Support Systems
Locomotion and Support Systems