Post on 02-Jan-2016
description
Locomotion Act, ability, or power of moving
The musculoskeletal system gives animals the ability to move
Provides form, support, stability, and movement to eh body
Bones Made of collagen and calcium salts
Bones change shape when osteoblasts (bone-building cells) and osteoclasts (bone-breaking cells) remodel them.
Joints are held together by ligaments
The connective tissue that attach muscles to bones are tendons.
Exoskeleton Encloses the bodies of arthropods
Supports the important internal organs and protects them from being damaged
Insects shed their exoskeleton to increase in size
Endoskeleton Found in all vertebrates
Made up of phosphate and calcium
Important to maintain the body shape, supports the soft-body tissues and protects the internal organs from getting injured
Certain parts store minerals
Hydrostatic Consists of internal body fluids in the confined body
cavity
The fluid is held under pressure in compartments and surrounded by muscles
This ensures the shape of soft-bodied organisms like earthworms and sea anemones.
Human Skeleton
Axial Skeleton Is the part of the skeleton that
forms an imaginary line down the back bone of the body
Is made out of
-skull
-vertebral column
-sternum and ribs
Appendicular Skeleton
Scapula- flat, triangular-shaped bone that forms the basis of the shoulder
Humerus- articulates with the scapula to form a ball-end socket joint at the shoulder
Ulna- longer bone of the forearm that articulates with the humerus
Radius- flattened, slightly curved bone in the hand
Pelvic Girdle- provides connection between the axial skeleton and hind limbs
Femur- largest bone in the human body. Forms a hind joint at the knee
Fibula- shorter and smaller bone, giving support to the leg
An organ system consisting of skeletal, smooth, and cardiac muscles
It permits movement of the body, maintains posture, and circulates blood throughout the body
Muscle cells (fibers) move by lengthening and contracting, a process that generates much of the body heat needed for survival
Muscular System
Three Types of Muscle Skeletal Muscle Smooth or Visceral Muscle Cardiac Muscle
Muscle
Striated voluntary muscles
Attached to bones by dense, fibrous connective tissue called tendons
Important in maintaining posture, providing support and allowing for movement
Skeletal Muscle
Muscles are made up of muscle bundles, which subdivide into muscle fascicles
Within each muscle fascicle are units called muscle fiber cells
Within each muscle fiber are contractile fibrils called myofibrils
A single myofibril is subdivided intro sarcomomeres or contractile units
Organization of Skeletal muscle
The functional unit in a muscle cell
Inside a sarcomere, there are two protein filaments Actin: thin filament Myosin: thick filament
Interaction of both proteins cause muscle contractions
Sarcomere
Found in the heart
Its action is beyond conscious control
When the skeletal muscles are exercised, they send signals to the heart via nerve cells to provide more oxygen
Cardiac Muscle
Found throughout the body (in the walls of blood vessels, the digestive tract, and internal organs)
Involuntary
They respond to demands for increased oxygen from the skeletal muscles by narrowing or widening blood vessels
Smooth Muscle
Tendons are tough bands of fibrous connective tissue that usually connect muscle to bone
Ligaments refer to fibrous tissue that connect bones to other bones Ex: head and neck, wrist, thorax, pelvis, knee
Ligaments
1. A nerve impulse is sent to a skeletal muscle.
2. The neuron sending the impulse releases a neurotransmitter onto the muscle cell.
3. The muscle depolarizes.
4. Depolarization causes the sarcoplasmic reticulum to release calcium ions.
5. These calcium ions cause the actin and myosin filaments to slide past each other.
6. The muscle contracts.
How does a muscle contract?
InvertebratesSponges
Cnidarians
Nematodes
Flatworms
Annelids
Hydrostatic Skeleton Many invertebrates have these skeletons.
As mentioned earlier, three types of skeletons: exoskeleton, endoskeleton, and hydrostatic skeleton.
How it Works Exterior muscles contract along the body of the
organism, causing the fluid filled chamber inside to move.
Similar to peristalsis in the human intestine.
Nematodes Locomotion in nematodes
RoundwormsImportant: Nematodes and annelids have a one way digestive track although they are invertebrates
Annelids Earthworms are annelids
Have better locomotion than nematodes because they are segmented, so they can control their peristaltic waves of motion better.