The Muscular System Chapter 7 I have husbandry

The Muscular System Chapter 7 “I have husbandry”

What do we call the study of muscles?

The Muscular System • • • > 600 muscles > half of body weight Determines form Maintains posture Produces body heat Forms internal organs

Tendon : Attaches muscle to bone

Aponeuros: Flat, ribbonlike tendon

Fascia : Encloses muscles and separates them into groups

Ligament : Attaches bone to bone or bone to cartilage

Attaching to a muscle… Origin: The less movable of the two points of attachment to a bone. Attaches to the fixed part of the skeleton.

Insertion: The point of attachment by a muscle to a moveable bone. Moves when a muscle is contracted.

Motor nerve: Causes a muscle to move by stimulating a group of muscle fibers

Muscle cells

Speed of muscle movement varies with muscle & size of structure to be moved…

Muscles are classified based on function, shape, and structure…

Skeletal muscle: • “Voluntary” because is controlled at will • “Striated” because of striped microscopic appearance • Fibers become shorter and thicker when muscle contracts

Striated Muscle

Smooth Muscle: • Also called visceral, nonstriated or involuntary muscle • Many internal organs are made of smooth muscle…

bladder

uterus

Smooth muscle vs skeletal muscle

Cardiac muscle is involuntary but does show very fine striations

cardiac striated smooth

Muscle Attachments: • Attachment to tendons (phalanges) results in movement and reduces bulk • Voluntary muscles usually attach to bone. o Attach to cartilage in larynx & thorax

Muscles may also be attached to skin, mucous membranes or the fascia of other muscles.