Download Muscular System Guided Notes

Name ______________________________
Date ________________ Period ________
The Muscular System
Introduction
• The human body has more than _______ individual muscles
• Bones and joints _________________________ movement
• Muscles cause bones and supported structures to move by alternating between _________________
_____________________________
Functions of Muscle
• Muscle has the _____________________________, permitting muscles to perform various function
• Functions:
• _______________________
• _______________________
• _________________ of body openings and passages
• ________________________________________________
Microscopic Anatomy of Skeletal Muscle
• Sarcomere—_____________________________ of a muscle fiber
• Organization of the sarcomere
• Myofilaments
• Thick filaments = ____________________ filaments
• Thin filaments = ____________________ filaments
• Thick filaments = myosin filaments
• Composed of the ____________________
• Has ATPase enzymes
• Myosin filaments have heads (extensions, or cross bridges)
• Myosin and actin _________________________________
• Thin filaments = actin filaments
• Composed of the ____________________
• Anchored to the Z disc
Functions of Muscle: Movement
• Skeletal muscles
• Attached to bones by ____________________
• Cross joints so when they contract, bones they attach to ____________
• Smooth muscle
• Found on _________________________
• Contractions produce movement of organ ____________________
• Cardiac muscle
• Produces atrial and ventricular _____________________
• This pumps blood from the __________________________________
Functions of Muscle: Stability
• Hold bones tightly together
• Stabilize ___________________
• Small muscles hold vertebrae together
• Stabilize the ______________________
Functions of Muscle: Control of Body Openings and Passages
• Sphincters
• ___________________ structures formed by muscles
• Control movement of substances _________________ of passages
• Example:
• A urethral sphincter prevents or allows _______________
Functions of Muscle: Heat Production
• Heat is released with _________________________________
• Helps the body maintain a _________________________________
• _________________ your body can make you warmer if you are cold
Types of Muscle Tissue
• Muscle cells
• Myocytes called ___________________________
• Sarcolemma – ____________________________
• Sarcoplasm – _______________________ of cell
• Myofibrils – ____________________________ in sarcoplasm
• Arrangement of filaments in myofibrils produces ____________________
Muscle Group
Major Location
Major Function
Mode of Control
Skeletal Muscle
Attached to __________ and
___________ of the face
Produces body movements and
facial expressions
_______________
Walls of _________________,
______________________, and
____________
Moves contents through organs;
vasoconstriction
_______________
Wall of the ____________
Pumps blood through heart
Smooth Muscle
Cardiac Muscle
_______________
Types of Muscle Tissue: Skeletal Muscle
• Muscle fibers respond to the neurotransmitter __________________________
• Causes skeletal muscle to ___________________
• Following contraction, muscles release the enzyme __________________________
• Breaks down _________________________
• Allows muscle to __________________
• Makes up about _____% of your muscles
Types of Muscle Tissue: Smooth Muscle
• Multiunit smooth muscle
• In the ________ of the eye and walls of ______________________
• Responds to neurotransmitters and hormones
• Visceral smooth muscle
• In walls of _________________________________
• Responds to __________________________
• Stimulate each other to contract so that muscle fibers contract and relax together in a rhythmic
motion – ________________________
• Peristalsis – rhythmic contraction that pushes substances through tubes of the body
• Neurotransmitters for smooth muscle contraction
• ____________________________
• ____________________________
• Will _______________________ contractions, depending on smooth muscle type
• Makes up about ____% of your muscles
Types of Muscle Tissue: Cardiac Muscle
• Intercalated discs
• __________________ groups of cardiac muscle
• Allow the fibers in the groups to contract and relax together
• Allows heart to _________________________
•
•
•
__________________________ – does not need nerve stimulation to contract
• _______________ speed up or slow down contraction
Neurotransmitters
• Acetylcholine – ____________ heart rate
• Norepinephrine – ____________ up rate
Makes up about ____% of your muscles
Production of Energy for Muscle
• ATP (adenosine triphosphate)
• A type of _____________________________
• Needed for sustained or repeated ___________________________
• Muscle cells must have three ways to store or make ATP
• Creatine phosphate
• _____________ production of energy
• Aerobic respiration
• Uses body’s store of _________________
• Lactic acid production
• _____________________________________
Production of Energy: Oxygen Debt
• Develops when skeletal muscles are used strenuously for several minutes and cells are low in oxygen
Production of Energy: Muscle Fatigue
• Condition in which a muscle has lost its ability to
contract
• Causes
• Accumulation of _____________________
• Interruption of the
______________________________ to a
muscle
• A motor neuron loses its ability to release
acetylcholine onto muscle fibers
Structure of Skeletal Muscles
• Skeletal muscles
• The _________________ components of the muscular system
• Composition: Connective tissue, Skeletal muscle tissue, Blood vessels, and Nerves
Structure: Connective Tissue Coverings
• Fascia
• Covers _____________ skeletal muscles
• _____________________ them from each other
• Tendon
• A tough, __________________________ made of fibrous connective tissue
• Connects _________________________________
• Aponeurosis
• A tough, _________________________________ made of fibrous connective tissue
• Attaches _________________________________
• Epimysium
• A thin __________________ that is just below the fascia of a muscle and surrounds the entire muscle
• Perimysium
• Connective tissue that divides a muscle into sections called _______________
• Endomysium
• Covering of connective tissue that _________________________________
Attachments and Actions of Skeletal Muscles
• Actions depend largely on what the muscles are __________________________
• Attachment sites
• Origin – an attachment site for a ___________________ bone
• Insertion – an attachment site for a ___________________ bone
• Movement usually produced by a __________________________
• Prime mover – muscle responsible for __________ of the movement
• Synergists – muscles that help the prime mover by ______________________________
• Antagonist (agonist) – produces movement ________________to prime mover
• Relaxes when prime mover contracts
Attachments and Actions: Body Movements
Flexion – bending a body part
Extension – straightening a body part
Hyperextension – extending a body part past the normal anatomical position
Dorsiflexion – pointing the toes up
Plantar flexion – pointing the toes down
Abduction – moving a body part away from the anatomical position
Adduction – moving a body part toward the anatomical position
Circumduction – moving a body part in a circle
Pronation – turning the palm of the hand down
Supination – turning the palm of the hand up
Elevation – lifting a body part; for example, elevating the shoulders as in a shrugging expression
Depression – lowering a body part; for example, lowering the shoulders
Muscle Strains and Sprains
• Strains – injuries due to ____________________ muscles or tendons
• Sprains – more serious injuries that result in _______________to tendons, ligaments, and/or cartilage of joints
• RICE is recommended treatment for either
• R__________ I__________ C__________ E__________
• Prevention
• ______________________________________
• A few minutes before an intense activity raises muscle temperature & makes muscle more pliable
• ______________________________________
• Improves muscle performance and should always be done after the warm-up or after exercising
• ______________________________________
• Before completely stopping prevents pooling of blood in the legs and helps remove lactic acid
from muscles
Aging and the Musculoskeletal System
• Contractions become slower and
not as strong
• ___________________
__________________ ability
decrease
• ____________ may decrease
• Assistive devices helpful
• Routine ___________________
• Swimming
• Physical therapy