1.04 Remember the structures of the muscular system

1.04 Remember the structures of the muscular system Essential Question What are the structures of the muscular system? 1.04 Remember the structures of the muscular system

1.04 Remember the structures of the muscular system Comprises nearly half our weight. Over 650 muscles. Each muscle is made up of hundreds or thousands of muscle fibers. 1.04 Remember the structures of the muscular system

The Muscular System: Muscle Fibers Bundles of threadlike structures called myofibrils Composed of: Myosin Actin Form overlapping pattern called sarcomere muscle muscle fiber sarcolemma sarcomere functional unit of muscle movement 1.04 Remember the structures of the muscular system

Structures of the muscular system Muscles Skeletal Smooth Cardiac Sphincter Connective tissue Tendons Fascia 1.04 Remember the structures of the muscular system

Structures of the muscular system Types of muscle Skeletal Smooth Cardiac Sphincter Body movements are determined by one or more of 3 principle types of muscles – skeletal, smooth and cardiac. These muscles are also described as striated, spindle shaped and non-striated because of the way their cells look under a microscope. Spincter muscles open and close to control passage of substances. 1.04 Remember the structures of the muscular system

Structures of the muscular system Types of Muscle Skeletal muscles Attached to bone Striated (striped) appearance Voluntary Multinucleated muscle cell bundles Attached to bones of skeleton. Called striped or striated because they have cross bandings of alternating light and dark bands running perpendicular to the lenths of the muscle. Also called voluntary because it contains nerves under voluntary control. Skeletal muscles consists of bundles of muscle cells that contain many nuclei (multinucleated). Each muscle cell is known as a muscle fiber. The cell membrane is sarcolemma and the cytoplasm is sarcoplasm. Skeletal muscles are over our “fleshy” body parts. They provide movement to the limbs, but contract quickly, fatigue easily, and lack the ability to remain contracted for prolonged periods. Control things like blinking the eyes, talking, breathing, dancing, eating, and writing are all produced by the motion of these muscles. 1.04 Remember the structures of the muscular system

1.04 Remember the structures of the muscular system

Mrs. Smith's Muscular System notes Pg. 394 - 398 TYPES OF MUSCLES SKELETAL - Attached to bone - Cause body movement - Voluntary muscle : you control Ex: Biceps, Triceps, Hamstrings, Quadriceps, Abdominals PG. 395

Structures of the muscular system Types of Muscle Smooth muscles Also known as visceral muscles Involuntary Located in walls of digestive system, uterus & blood vessels Smooth muscles are small and spindle-shaped. There is only one nucleus, located in the center of the cell. Smooth muscles called smooth ecause they are unmarked by any distinctive striations. They are unattached to bones, they act slowly, do not tire easily and can remain contracted for a long time. Smooth muscles are ont under conscious control so called involuntary. Their actions are controlled byy the autonomic nervous system. They are found in the walls of internal organs, including the stomach, intestines, uterus and blood vessels. They help push food along the length of the alimentary canal, contract the uterus during labor and childbirth and control the diameter of the blood vessels as the blood circulates throughout the body. 1.04 Remember the structures of the muscular system

Mrs. Smith's Muscular System notes Pg. 394 - 398 TYPES OF MUSCLES SMOOTH - Produce movement in your internal organs & passageways. - Involuntary muscle: automatic contractions Ex: pupil, stomach, liver, bladder, esophagus, lungs, blood vessels PG. 395

Structures of the muscular system Types of Muscle Cardiac muscle Found only in the heart Striated, branched Involuntary Cells are fused- when one contracts, they all contract, creating the heartbeat Cardiac muscle is found only in the heart. Cardiac muscles are striated and branched and are involuntary. The cardiac cells are joined in a continuous network without a sheath separation. The membranes of adjacent cells are fused at places called intercalated discs. A communication system at te fused area will not permit independent cell contraction. When one cell receives a signal to contract, all neighboring cells are stimulated and they contract together to produce the heartbeat. When the heart beats normally, it holds a rhythm of about 72 beats per minute, however the activity of various nerves leading to the heart can increase or decrease its rate. Cardiac muscle requires a continuous supply of oxygen to function. If the oxygen supply is cut off for even 30 seconds, the cardiac muscle will start to die. 1.04 Remember the structures of the muscular system

Mrs. Smith's Muscular System notes Pg. 394 - 398 TYPES OF MUSCLES CARDIAC - Forms the walls of your heart. - Involuntary muscle : automatic contractions - Works non-stop until… - on avg.  60 – 80 beats / min. In shape Out of shape Less More PG. 395

Structures of the muscular system Types of Muscle Sphincter muscles Also called dilator muscles Special, circular muscles Located in the digestive system urinary system These muscles are in the openings between the esophagus and stomach, and the stomach and small intestine. They are also found in the walls of the anus, the urethra, and the mouth. They open and close to control the passage of substances. 1.04 Remember the structures of the muscular system

Structures of the muscular system Types of Muscle Skeletal Smooth Cardiac Sphincter 1.04 Remember the structures of the muscular system

Structures of the muscular system Types of Connective tissue Tendons Fascia The muscular system is not only made up of muscle, but also some connective tissues as well. 1.04 Remember the structures of the muscular system

Structures of the muscular system Connective tissue Tendons dense bands that connect skeletal muscle to the bone There are over 650 different muscles in the body. For any of these muscles to produce movement in any part of the body, it must be able to exert its fors upon a movable object. They must be attached to pones for leverage in order to have something to pull against. They only pull, the never push. Muscles are attached to the bones of the skeleton by nonelastic cords called tendons. Bones are connected at joints 1.04 Remember the structures of the muscular system

Structures of the muscular system Connective tissue Fascia Fibrous connective tissue sheets that wrap around muscle bundles These help to hold the muscles into place. 1.04 Remember the structures of the muscular system

How do skeletal muscles get their names? Location Location of origin and insertion Size Action flexor Direction Extensor Number of origins Depressor Location – Frontalis (forehead) Size- gluteus maximus (largest muscle in the buttock) Direction of fibers- external abdominal oblique (edge of the lower rib cage) Number of origins- biceps (two-headed muscle in the humerus) Location of origin and insertion- sternocleidomastoid (origin in the sternum) Action flexor - flexor carpi ulnaris (flexes the wrist) Levator and depressor – depressor anguli oris (depresses the corner of the mouth: raises or lowers body parts) However, not all muscles are named by the above methods! 1.04 Remember the structures of the muscular system

1.04 Remember the structures of the muscular system Head & Neck Muscles Head – muscles of expression such as anger, fear, grief, joy pleasure and pain. Muscles of mastication (chewing) to open and close the jaw. Muscles of the tongue, pharynx, soft palate. Muscles that move the head cause extension, flexion and rotation. Neck – moving the head, muscles moving the hyoid bone and the larynx, muscles moving the upper ribs 1.04 Remember the structures of the muscular system

Torso/Trunk (anterior) 1.04 Remember the structures of the muscular system

Torso/Trunk (anterior) Muscles for breathing and movement of the abdomen and pelvis 1.04 Remember the structures of the muscular system

Torso/Trunk (posterior) Muscles that move the vertebral column and scapula 1.04 Remember the structures of the muscular system

1.04 Remember the structures of the muscular system Upper extremities Muscles that move the humerus and the forearm, hand, wrist and fingers 1.04 Remember the structures of the muscular system

1.04 Remember the structures of the muscular system Lower extremities Muscles that act on the pelvis, move the femur and leg, and attach to the ankles, feet and toe digits. Athletes often pull what are known as the hamstrings. 1.04 Remember the structures of the muscular system

The muscular system review Anterior view 1.04 Remember the structures of the muscular system

The muscular system review Posterior view 1.04 Remember the structures of the muscular system

1.04 Remember the structures of the muscular system Essential Question What are the structures of the muscular system? 1.04 Remember the structures of the muscular system