The Muscular and Skeletal Systems

Phyla Cnidaria Porifera Invertabrate Lacks any true tissues Endoskeleton consist of hard needle-like structures of inorganic material

Phyla Annelida Hoplolaimus Galeatus Has an hydrostatic skeleton Muscle Contraction results in thrashing motion Body wall muscles aligned longitudinally

Hydrostatic Skeleton

Phyla Arthropoda Scorpio Maurus Relies on exoskeleton for structure Segmented body with jointed appendages for movement

Mammalia PHYLA MAMMILIA H. Sapien Three types of muscle -Skeletal -Cardiac - Smooth

Skeletal muscle is voluntary, so you can move at will Skeletal muscle is voluntary, so you can move at will. It’s attached by tendons and ligaments to bones throughout the body Cardiac muscle is involuntary and contracts in response to electrical stimulation in the heart Smooth muscles are involuntary internal muscles that form the walls of organs and blood vessels. They respond to both nervous stimulation and movement of the skeletal muscles.

The breakdown of a muscle fiber

The Sliding-Filament Model of Muscle Contraction

Tropomyosin and troponin are both regulatory proteins bound to strands of actin. A muscle fiber at rest, tropomyosin covers the myosin-binding sites. This prevents actin and myosin from interacting. When Calcium Ions accumulate in the cytosol, they Bind to the troponin complex. This causes it to Shift along the actin strand exposing different Myosin-binding sites When Calcium ion concentration rises, the thin and thick filaments slide past each other and the fiber contracts Conversely when the concentration is lowered, the binging sites are covered and contraction stops

Skeletal systems transform muscle contraction into movement With the muscle attaching to two parts of the skeleton, muscle fibers can be shortened in a contraction producing a movement

Hardened internal skeletons are called endoskeletons Three major types of joints on the human body are -Ball and Socket joint -Hinge joint -Pivot joint Each one has a different range of motion

Liam Hoekstra, the Mini Superman Rare genetic disorder Myostatin-related muscle hypertrophy First discovered in beef cattle in late 1990’s Prevents the body from producing myostatin a limiting factor to muscle size Little to no body fat Incredibly fast metabolism Little is known about the disorder, but side effects of a child without body fat can lead to stunted growth and impaired central nervous system

Muscular Dystrophy (MD) is an inherited muscle disease in which muscle fiber are unusually susceptible to damage Primarily affects voluntary muscles, which become progressively weaker throughout the stages Fat and connective tissue often begin to replace muscle fibers Some types of MD affect cardiac muscle as well

Signs and symptoms of MD include -Muscle weakness -Apparent lack of coordination -Progressive crippling, resulting in fixations of the muscles around your joints and loss of mobility. Specific signs and symptoms vary from each form of the disease. Muscular Dystrophy is a general term describing a group of inherited diseases. Each form of MD involves a genetic mutation. The most common types appear to be caused by a genetic deficiency of the muscle protein dystrophin

Treatments and Medicines Presently we do not have a cure for muscular dystrophy. The best we can offer are physical therapies to reduce the pain of the muscles contracting or surgery if necessary However in some cases doctors may prescribe medication that Is capable of slowing the muscle deterioration. The anti- inflammatory corticosteroid prednisone may help improve muscle strength and delay the progression of some muscular dystrophies