9CardiacForm walls of heartContract to circulate bloodInvoluntary: function without conscious thought or control
10Visceral (Smooth)Found in the internal organs of the body such as the digestive system, respiratory system, blood vessels, and eyes.Contract to cause movement in these systemsInvoluntary: function without conscious thought or control
11 Skeletal Attached to bones Cause body movement Voluntary: person has control over their action
12Functions of Skeletal Muscle: Attach to bones to provide voluntary movementProduce heat and energyHelp maintain postureProtect internal organs
13Methods of Attachment to Bones: TendonStrong, tough connective tissue cordExample: Achilles tendon which attaches the gastrocnemius muscle on the calf of the leg to the heel bone.
14FasciaTough, sheetlike membraneCovers and protects tissueExample: lumbodorsal fascia which surrounds the deep muscles of the trunk and back
15Origin and InsertionWhen muscles attach to bones, one end becomes the origin and one end the insertionOrigin: end that does not moveInsertion: end that moves when muscle contracts
16Movements of Muscles: Adduction: moving body part toward the midline Abduction: moving body part away from midline
17Flexion: decreasing the angle between two bones or bending a body part Extension: increasing the angle between two bones or straightening a body part
18Rotation: turning a body part around its own axis; turning the head from side to side Circumduction: Moving in a circle at a joint; Example – swinging the arm in a circle with the trunk flexed forward at the waist.
19Toe-down motion of the foot at the ankle Dorsiflexion:Turn your foot or toes upward.Plantar Flexion:Toe-down motion of the foot at the ankle
20Muscle Tone:Muscles are partially contracted at all times even though they may not be in use.This state of partial contraction is known as muscle tone.Also described as a state of readiness to act.
21Can occur in severe illness such as paralysis Loss of muscle toneCan occur in severe illness such as paralysisWhen muscles are not used for a long period of time, they can atrophy or waste awayLack of use can result in a contractureSevere tightening of a flexor muscleResults in bending of a jointFoot drop is a common contractureMany joints such as fingers, wrists, and knees can be affected.
22 Increase in muscle tone Can occur with brain damage Resistance is felt in muscles; rocking motion can help to normalize tone