Muscular System

Three Types of Muscle

• ______________

• ______________

• ______________

Skeletal Muscle• Attaches to skeleton via _________, contracts to move _________

• ___________

• ___________ appearance

Smooth Muscle• Found on the walls of ________ ________ and ________ (stomach, blood vessels)

• ______________

• _________ appearance

Cardiac Muscle• Forms the walls of the __________

• _____________

• ____________ appearance

Tendons• Attach muscle to bone

• Defined as ________ or _________

•When describing attachment sites, it’s common to state the origin and insertion of the muscle

Origin vs. Insertion•Origin- usually attached to the ________ bone of a joint, typically not as ________

• Insertion- usually attached to the more _________ bone and typically more _________

Origin vs. Insertion – Biceps Brachii

• Origin: Long Head: Supraglenoid tubercle of the scapula Short Head: Coracoid process of scapula

• Insertion: Posterior border of the bicipital tuberosity

Muscle Contraction•Muscles pull on bones to create ______________

• Contraction: Origin and insertion move __________ ___________

• Stretched: Origin and insertion move _________ from each other

Muscle Contraction• Prime Mover: Muscle that creates a ________ __________(aka _________)

• Antagonist: _________ muscle group

• Examples of agonist antagonist pairs?

Muscle Fiber Types• Divided into two categories based on how quickly they contract

• ________ Twitch

• ________ Twitch

Slow-Twitch• Relatively large amounts of ___________•Mitochondria: where __________ metabolism occurs

• More __________ than fast-twitch fibers•Capillaries: Smallest ________ vessel that supplies blood to tissues, site of all gas and nutrient exchanges within __________________ system

Slow-Twitch• Contract more slowly than _______ twitch

• Lower ________ outputs, but more _________ and _________ resistant than fast twitch fibers

Fast-Twitch• Subdivided into fast-glycolytic and fast-oxidative glycolytic fibers

• Type IIX- __________ _____________• Type IIA- _____ - _______ __________

Fast-Twitch-IIX• ________ amount of mitochondria

• _________ _________ for aerobic metabolism

• ________ more easily than slow twitch

Fast-Twitch-IIX• Vast amount of __________ capacity

• Largest and _________ fibers

• Produce the ________ _______of all skeletal muscle fibers

Fast-Twitch-IIA• Possess speed, fatigue and force production capabilities somewhere ___________ Type 1 and Type IIX

• Also called __________ fibers

Muscle Fiber CompositionType 1 Type IIa Type IIx

Speed of contraction Low Medium High

Force Capacity Low Medium High

Fatigue Resistance High Medium Low

Mitochondrial Content High Medium Low

Size Low Medium High

Efficiency High Medium Low

Aerobic Capacity High Medium Low

Anaerobic Capacity Low Medium High

Muscle Fiber Composition• Typically an equal mixture of fast and slow twitch fibers• Influenced by _________, _________, __________ _________• _____ play a role in sports performance• Power athletes high percentage of ______ twitch, endurance _____ twitch

Muscle Fiber Anatomy

• Fascia- Thin sheets of __________ tissue membranes – hold ________ fibers in place

• ___________• ___________• ___________

____________ outermost layer of connective tissue

_____________ bundles of muscle fibers surrounded by connective tissue _____________

Connective Tissue surrounding individual muscle fibers

Muscle Fiber Anatomy

•Muscle fibers are made up of myofibrils (protein filaments) composed of a series of repeating segments called _____________

Muscle Fiber Anatomy• Sarcomeres- made up of ____________ (protein filaments) - functional contracting unit of skeletal muscle – section between 2 _____________

• Myosin-_______ dark bands called _____bands

• Actin- _____ light bands called ____bands

A

Enlargement of a Sarcomere

________Thick Myofilament

_______Thin Myofilament

__________

Muscle Contraction- Key Terms• Adenosine Triphosphate (ATP)– High energy _________ molecule used in muscular ___________

• ______________- A chemical substance that transmits nerve impulses across synapses

• Synapse – region of ______________ between neurons

Muscle Contraction- Key Terms• Acetylcholine- most common

_____________ in the body – located in the Central and Peripheral Nervous system

• __________- used to expose binding sites on actin filaments

• Troponin- ___________ muscle contraction from occurring when a muscle is at rest

Sliding Filament Model• Explanation of how muscles produce ________ and ___________

•Myosin and actin filaments _____ past each other shortening the entire ________ of the sarcomere – draw Z-Lines closer together

Sliding Filament Model•When _____________ is released from the Central Nervous System and detected, ____________ is released.

•Calcium exposes __________ sites along the ________ for the __________ to attach.

• If sufficient ATP is present, cross-bridges are formed and the _______ pulls the ________ toward the center, thereby shortening the sarcomere.

Sliding Filament Model

Examples of Sliding Filament Model• Sliding Filament Model