Presentation on theme: "Each motion had a limited range of movement. The types and ranges of movement differed. Different joints allow rotational movements, angular movements,"— Presentation transcript:
Each motion had a limited range of movement. The types and ranges of movement differed. Different joints allow rotational movements, angular movements, and gliding movements.
Chapter 10: Movement and Forces 10.1 The skeletal system provides movement and protection 10.2 The muscular system makes movement possible 10.3 Muscles exert forces 10.4 Bones and joints at as levers
Match each definition with the terms. 1. a bony structure that allows rotation 2. the skeleton division containing the skull 3. the part of a bone that produces red blood cells a. compact bone d. ball-and-socket joint b. axial skeleton e. marrow c. immovable joint d b e
Muscles perform important functions Beating heart, moving food through your digestive system, blinking eyes Some movements are automatic, some you control Muscles help Produce movement regulate your body’s temperature (keep it stable) maintain your body’s posture
Movement Muscular system – consists of skeletal muscles (attached to the skeleton) Most skeletal muscles are attached to bones by tendons Made of muscle fibers (many muscle cells) Contract – shorten / relax – lengthen Most muscles work in coordinate groups Bend arm and release: biceps/triceps coordination
Maintaining Body Temperature Homeostasis: the balance of conditions in the body A muscle contracts releases heat Shiver: quick muscle contractions release heat to warm your body
Maintaining Posture Gravity is pulling your body down, but most muscles are always a little bit contracted Called tension, or muscle tone This is present even when sleeping! Muscles make contracting and relaxing adjustments to keep you sitting or standing These are automatic
Types of Muscles All contract and relax Perform different functions Skeletal attached to the skeleton under voluntary control. Smooth located in walls of some organs under involuntary control Cardiac located in the walls of the heart under involuntary control
Skeletal Muscles Attached to bones Help give the body its shape Voluntary/controlled movement ~ “voluntary muscles” Long fibers made of many bundles made of many cells Cells can have more than one nucleus Slow twitch – move slow but can sustain tension for longer periods Fast twitch – move quick but can only sustain tension for shorter periods
Smooth Muscles Involuntary muscle Contracts slowly Walls of stomach and intestines helps push food through the digestive system Also found in blood vessels helps regulate blood pressure
Cardiac Muscles Involuntary muscle Only found in the heart Each cardiac muscle cell is branched cells connect in a chain The chains form webs and layers that allow cardiac muscle cells to contract together and make the heart beat
Checking in… What do the bundles that make up skeletal muscle do? One type allows muscles to move slowly and maintain tension for a long time. Another allows muscles to move more quickly and sustain tension for a shorter period. Why are skeletal muscles called voluntary muscles? They move when you want them to. Compare and contrast the three types of muscle: skeletal, smooth, and cardiac. Skeletal muscles give the body shape and control movement. They are voluntary muscles. Smooth muscles contract without voluntary control. They are found in the walls of the stomach, intestines, and blood vessels. Cardiac muscle moves without conscious control and is found only in the heart.
Skeletal muscles, tendons, and joints allow bones to move Many skeletal muscles are attached to your bones by tendons Tendons: strong connective tissue Muscle contracts and shorten pull the tendon tendons pulls on the bone to make it move Muscles can only contract or relax. By contracting, they pull on the tendons. How do muscles move bones?
Movement Muscles must work together in coordinated groups Muscle groups produce movement in opposite directions A muscle contracts and shortens – it exerts a force Counterpart relaxes Which muscles work together to bend and extend your leg?
Movement Lift your leg without bending your knee Which muscles must contract in order to keep your knee from bending? What if you point your toes? Some of the muscles in your leg are working to stabilize the joints Other muscles are contracting to produce the controlled movement Muscular system + skeletal system + BRAIN!
Muscles grow and heal Baby neck muscles not strong enough to hold up head Childhood/adolescence: develop muscular coordination and become more graceful in their movements Exercise: muscles may get big # muscle fibers does NOT increase thickness of the muscle fibers and surrounding tissues increases Muscles can become sore during or after exercise: During exercise the muscle cells may not receive enough oxygen for cellular respiration switch to fermentation for energy Fermentation causes the buildup of lactic acid in muscles cramps or aches Muscles can also be damaged (overstretched or torn)