Movement Animal may be stationary and have moving parts, or may be mobile How do animals move? How do they overcome fri

1. Movement Animal may be stationary and have moving parts, or may be mobile How do animals move? How do they overcome friction and gravity in their various environments? What supportive/protective structures are required?

2. What modes of transport are there? in water on land flying All require a lot of energy Swimming is the most efficient Larger animals are more efficient, in terms of body weight

4. Swimming Friction is a big problem in water Gravity is not (as long as animal is buoyant) Some animals have fusiform bodies Others have appendages to help them swim

6. Locomotion on land Walking, running, jumping Appendages Muscles Balance Crawling (friction, not gravity) How are muscles arranged?

8. Flying Lift + thrust > weight + drag Wing design Weight

9. Mechanisms of movement Protozoans amoeboid movement: actin-myosin network (microfilaments) adhesion proteins (also seen in cells in complex animals that move in the same way ciliary/flagellar movement (microtubles) sliding filament model?

10. Multicellular animals muscles Muscles work against skeletons Three main types of skeletons hydrostatic exoskeletons endoskeletons

11. Hydrostatic skeleton Fluid-filled compartment cnidarians, flatworms, nematodes, annelids Animals with true body cavities exhibit peristalsis (longitudinal and circular muscles) Simpler animals have only longitudinal muscles

13. Exoskeletons Deposited on surface of animal mollusks, arthropods (Most) mollusks form shell that increases in size Arthropods have a cuticle secreted by epidermis protein-chitin complex Thicker in protective areas, thinner at joints Animals must molt periodically

14. Advantages of exoskeleton? Can support more weight, but animals are small enough that they will not collapse under the weight of the exoskeleton

15. Endoskeleton Formed within body Composed of bone and cartilage Bone is reservoir for calcium and phosphorus In amniote vertebrates, also site of blood cell formation

17. Cartilage Notochord serves as stiffening device in protochordates and vertebrate larvae and embryos Large cells surrounded by elastic and fibrous tissue Replaced by spinal column except in hagfishes Cartlaginous skeletons seen in jawless fishes and elasmobranchs (sharks, skates, rays)

18. Other vertebrates have bony skeletons interspersed with cartilage (Cartilage overlaid with bone during development) Hyaline cartilage most common Some invertebrates (e.g., mollusks) have tissue similar to cartilage

19. Functions of bone (skeleton) Support and protection Blood cell formation Mineral storage (calcium especially) Site for muscle attachmentbody movement

20. Compact bone osteocytes within lacunae arranged in concentric circles called lamellae This surround a central canal; complex is called Haversian system Canaliculi connect osteocytes to central canal and to each other

22. Prenatal development skeleton is mostly cartilaginous Cartilage cells and then osteoblasts start to deposit minerals Cartilaginous disk (epiphyseal disk) remains in epiphysis Cells eventually stop dividing

23. Adults continually break down and build up bone Osteoclasts remove damaged cells and release calcium into blood Osteoblasts remove calcium from blood and build new matrix. They become trapped osteoclasts

24. Axial skeleton skull (cranium and facial bones) hyoid bone (anchors tongue and muscles associated with swallowing) vertebral column (vertebrae and disks) thoracic cage (ribs and sternum) Appendicular skeleton pectoral girdle (clavicles and scapulae) upper limbs (arms) pelvic girdle (coxal bones, sacrum, coccyx) lower limbs (legs)

26. Joints Immovable (synarthoses) bones sutured together by connective tissue: skull Slightly movable (amphiarthoses) connected by fibrocartilage or hyaline cartilage: vertebrae, rib/sternum joint, pubic symphysis Freely movable (diarthroses)- separated ligaments- hold bones together tendons- muscle to bone lined by synovial membrane

28. Skeleton and other systems Skin makes vitamin D which enhances calcium absorption Skeleton stores calcium for muscle contraction, nervous stimulation, blood clot formation Red marrow- site of blood cell formation Calcium levels regulated by parathyroid hormone and calcitonin kidneys (can help provide vitamin D) digestive system (can release calcium into blood)

29. Vertebrates will have different types of skeletons depending on their size and needs Variations in: vertebrae number of ribs usually paired appendages girdles (pelvic, pectoral) modification of pentadactyl limb

30. Posture Larger animals bear stress along long axis of bone, i.e., more upright posture Smaller animals bear weight along transverse axis of bone; more crouched posture

32. Movement: muscle moves against skeleton Skeletal muscles are attached to bones by tendons (bones are attached to each other by ligaments) Muscles are attached in opposing pairs (when on contracts, the other relaxes) How does (skeletal) muscle contract? the sliding filament model is based on microscopic observations of muscle

37. Critical role for calcium in muscle contraction Calcium must bind to actin so that myosin binding sites are exposed Regulated by sequestration of calcium in the sarcoplasmic reticulum of muscle cell “Sarco” prefix refers to muscle cells

40. Muscle contraction is graded Action potentials can be summated; many cells contract Skeletal muscles are innervated by motor units (one neuron can stimulate many muscle fibers)

41. A single somatic motor neuron can produce an axon with several terminal branches. Each stimulates a different muscle fiber. Motor unit- a motor neuron and the muscle fibers it innervates

43. Control of skeletal muscle contraction number of fibers stimulated size of muscle number of motor units size of motor unit how many times fiber is stimulated (summation) length of muscle at time of contraction (longest at rest; more cross bridges can form)

44. Energy requirements of skeletal muscles At rest, most energy obtained from fatty acids Exercise: glycogen and glucose also used ATP is used for: movement of cross bridges pumping of calcium into sarcoplasmic reticulum (i.e., for contraction AND relaxation)

45. Oxidative phosphorylation (O2-dependent) blood deep breathing myoglobin Glycolysis glycogen fatigue: depletion of glycogen accumulation of lactic acid Creatine phosphate- first source

47. Not all muscles have the same contraction speed Slow-twitch- red fibers; lots of myoglobin and blood supply back and legs (in humans) Fast-twitch- fewer capillaries and less myoglobin (white fibers)- anaerobic activity (glycolysis) tend to be larger in diameter arms Intermediate fibers- fast twitch but with high oxidative capacity. Resistant to fatigue

48. Upper motor neuron control Spinal reflex activity Output from primary motor cortex Multineuronal system (posture, movement of trunk and limbs) Modulated by motor cortex, cerebellum and basal nuclei Information “delivered” by muscle spindles (muscle length) Golgi tendon organs (tension)

49. Cardiac and smooth muscle Cardiac- striated muscle cells can produce impulses and contract simultaneously gap junctions allow impulses to be conducted from cell to cell can produce action potential simultaneously usually originate from SA node autonomic innervation

50. Smooth muscle Often arranged circularly, sometimes longi- tudinally as well No sarcomeres, lots of actin. Myosin arranged so cross bridges can form along its length Muscle can contract when stretched