Muscle Strength and Physiology

These flashcards cover key vocabulary and concepts related to muscle strength and physiology as outlined in the lecture notes.

Hand Grip Strength Assessment

A method used to evaluate muscle strength via the strength of grip.

Intrinsic Muscles of the Hand

Muscles located within the hand that enable fine motor movements.

Extrinsic Muscles

Muscles originating outside of the hand that contribute to hand movement.

Isometric Contraction

Muscle contraction without change in muscle length.

Tension-Length Relationship

Describes how the length of a muscle influences its ability to generate force.

Neuromuscular Junction

The synapse or junction where information is transmitted from a motor neuron to a muscle fiber.

Sliding Filament Theory

The mechanism explaining muscle contraction involving the sliding of actin and myosin filaments.

Sarcoplasmic Reticulum

A specialized endoplasmic reticulum in muscle cells that stores calcium ions.

Calcium Ions (Ca2+)

Essential ions that trigger muscle contraction by enabling actin-myosin interactions.

Fast Twitch Fibers

Muscle fibers that are designed for quick bursts of power but fatigue quickly.

Sarcopenia

Age-related muscle loss resulting in decreased muscle mass and strength.

Motor Unit

A single motor neuron and all the muscle fibers it innervates.

Creatine

A molecule that helps supply energy to muscles, especially during short bursts of high-intensity activity.

Acetylcholine

A neurotransmitter that transmits signals from motor neurons to muscle fibers.

T-tubules

Extensions of the muscle cell membrane that facilitate rapid transmission of electrical signals.

Myofibrils

The long, threadlike structures found in muscle cells, responsible for contraction.

Cross-Bridge Cycle

Cyclic binding and release of myosin heads from actin filaments during muscle contraction.

Recovery after contraction

The process of returning calcium ions to the sarcoplasmic reticulum and covering actin binding sites.

Easy to measure, noninvasive, predictive of health outcomes

A vital sign should be:

Muscle weakness often appears before disease symptoms

What is the early warning sign in hand grip strength?

Sacropenia

Hand grip strength is often used to help diagnose ______ an age related muscle loss

Frailty

Hand grip strength tests are often used in ______ assessments in older adults

Metabolic and circulatory

Muscle strength reflects how well the body handles ____ and _____ demands

Overall muscle strength, frailty, nutritional status, cardiovascular health, neurological health, recovery progress, and biological age

What are the 7 main categories hand grip strength measures?

Sacropenia because it prevents age related muscle loss and osteoporosis because it improves bone mineral density

What are the two main conditions resistance training can prevent in older adults and why?

Fights Sacropenia, functional independence, reduces fall risk, strengthens bones, improves cardiovascular health, improves immune function and supports mental health

What are the 7 main reasons resistance training is beneficial for older adults?

Epimysium

Surrounds entire muscle

Perimysium

Surrounds bundles of muscle fibers

Endomysium

Surrounds individual muscle fibers

Sarcolemma

Muscle cell membrane

Fascicle, muscle fiber, myofibril, myofilament

What are the four main parts of the muscle starting with muscle fiber?

Power

_____ reveals how effectively strength is used