Human Biology The Muscular System
The Muscular System… The muscular system allows body movement and maintains posture Your body has more than 600 muscles Your muscles work even when you are asleep
The Muscular System… Most muscles, or muscle tissue, are composed of muscle fibers that run beside, or parallel to, one another These muscle fibers are held together in bundles of connective tissue Each muscle fiber is actually a single cylinder-shaped cell
The Muscular System… The function of muscle tissue is to contract, or shorten
The Muscular System… Types of Muscles There are three types of muscle tissue in the human body Skeletal muscle Smooth muscle Cardiac muscle Each type of muscle tissue has a characteristic structure and function
The Muscular System… Skeletal muscle Attaches to and moves bones By contracting, skeletal muscle causes your arms, legs, head, and other body parts to move
The Muscular System… Under a microscope, skeletal muscle appears banded, or striated Skeletal muscle is also known as striated muscle
The Muscular System… Skeletal muscle moves only when you want it to Voluntary muscle Skeletal muscles react quickly when you want them to Skeletal muscles tire easily
The Muscular System… Smooth muscle Has no bands-hence the name Help control breathing, blood pressure, and the movements of the digestive system Has no bands-hence the name In general, smooth muscles can contract without your actively causing them to Involuntary muscle
The Muscular System… Smooth muscles react slowly Smooth muscles tire slowly
The Muscular System… Cardiac muscle Found only in the heart Branches out in many directions, weaving a complex mesh Contractions of cardiac muscle cause the heart to beat
The Muscular System… Cardiac Muscle Involuntary muscle Does not tire
The Muscular System… Action of skeletal muscles Muscles do work only by contracting In order for muscles to cause any kind of movement, they must work in pairs Nerves carry messages from the brain and the spinal cord to the muscles, signaling them to contract
The Muscular System… Injuries to the muscular system Strain, tear
The Muscular System… Review Muscle tissue is made of fibers bundled together by connective tissue Muscle tissue moves only by contracting There are 3 types of muscle tissue Skeletal Smooth Cardiac
The Muscular System… Skeletal muscle Smooth muscle Cardiac muscle Permits voluntary movement Are connected to bone Smooth muscle Help control breathing, blood pressure, and movements in the digestive system Cardiac muscle Makes the heart beat
The Muscular System… All skeletal muscles work in pairs When one contracts, the other relaxes