Chapters 3, 4, and 5:

What are the primary components of muscle composition?

What are the primary components of muscle composition?

Muscles are primarily made up of: Water (65-75%), Protein (20%), Other components (lipids, carbohydrates, electrolytes, ATP, phosphocreatine) (5%).

What is the function of muscle fibers?

Muscle fibers produce force when stimulated, which allows movement; this occurs as chemical energy from ATP converts into mechanical energy.

What are the different types of connective tissues in muscles and their functions?

Tendons connect muscles to bones, Epimysium covers the whole muscle, Perimysium covers bundles of muscle fibers (fasciculi), Endomysium covers individual muscle fibers.

What is a sarcomere and what happens to it during muscle contraction?

The sarcomere is the basic unit of contraction in a muscle; during contraction, it shortens as actin slides over myosin, making the H zone disappear and the I bands shorten.

What are the main types of muscle fibers?

Type I (slow-twitch): endurance activities; Type II (fast-twitch): short bursts of activity.

Explain the sliding filament theory.

The sliding filament theory describes how muscle contraction occurs as actin filaments slide over myosin filaments, shortening the sarcomere.This process is powered by ATP and involves the binding and unbinding of myosin heads to actin, leading to muscle shortening.

Define proprioception.

Proprioception is the body's ability to sense its position in space, facilitated by receptors called proprioceptors.

What factors influence the amount of force a muscle can produce?

Factors include cross-sectional area, muscle length, and neural influences.

Describe the length-tension relationship in muscles.

A muscle produces maximum force at a specific length where actin and myosin filament overlap is optimal.

What adaptations occur in muscles due to resistance training?

Strength gains occur first due to neural changes, followed by muscle hypertrophy.

What are the key functions of the nervous system?

Starting movements through signals to muscles and maintaining homeostasis.

Describe the organization of the nervous system.

The nervous system consists of two parts: Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What are the divisions of the peripheral nervous system (PNS) and their functions?

The PNS divides into the Somatic (voluntary movements) and Autonomic nervous system (involuntary functions).

What are the branches of the autonomic nervous system and their roles?

Sympathetic Nervous System (fight-or-flight) and Parasympathetic Nervous System (rest and digest).

What are the main components of a neuron and their functions?

Dendrites (receive impulses), Cell Body (nucleus), Axon (carries impulse away from the body).

How are impulses conducted along neurons?

Impulses travel as action potentials; myelination increases conduction speed through saltatory conduction.

What is a synapse and how does it function?

A synapse is where two neurons communicate; neurotransmitters are released and bind to receptors to transmit signals.

Explain the neuromuscular junction.

The neuromuscular junction connects a motor neuron to a muscle fiber; acetylcholine is released to trigger muscle contraction.

What is a motor unit and how does it operate?

A motor unit consists of a motor neuron and the muscle fibers it controls, contracting together upon stimulation.

Describe the size principle of motor unit recruitment.

Motor units are recruited from smallest to largest, with slow-twitch units activated first.

What are the neural adaptations that occur in response to exercise?

Adaptations include increased motor unit recruitment, firing rates, coordination, and timing of contractions.

What are the main components of the cardiovascular system?

Key components include the heart, blood, and blood vessels.

Differentiate between pulmonary and peripheral circulation.

Pulmonary circulation involves blood flow between the heart and lungs; peripheral circulation involves blood flow from the heart to the rest of the body.

Describe the structure of the heart.

A four-chambered organ with two atria and two ventricles; valves ensure unidirectional blood flow.

Explain the phases of the cardiac cycle.

The cardiac cycle includes systole (contraction) and diastole (relaxation).

What are the mechanisms of heart rate control?

Heart rate control involves intrinsic mechanisms (SA node) and extrinsic controls (nervous system and hormones).

Define cardiac output and how it's calculated.

Cardiac output (Q) is the volume of blood pumped per minute, calculated as Q = HR x SV.

What is stroke volume and what factors influence it?

Stroke volume (SV) is the blood ejected from the ventricle; influenced by End-Diastolic Volume (EDV) and End-Systolic Volume (ESV).

What factors contribute to venous return?

Venous return is aided by venoconstriction, muscle pump, and respiratory pump.

Explain the Frank-Starling Mechanism.

The Frank-Starling Mechanism describes how stroke volume adjusts based on venous return.

What are the components of blood?

Blood consists of plasma and formed elements (red blood cells, white blood cells, platelets).

Describe the redistribution of blood flow during exercise.

Blood flow is redirected to working muscles and away from non-essential organs during exercise.

What is blood pressure and what influences it?

Blood pressure is the force exerted by blood on vessel walls, affected by cardiac output and total peripheral resistance.

Differentiate between systolic and diastolic blood pressure.

Systolic blood pressure is the maximum pressure during ventricular contraction; diastolic is the minimum pressure during relaxation.

What factors determine oxygen delivery to tissues?

Oxygen delivery relies on cardiac output and arteriovenous oxygen difference (a-v O2 diff).

explain the muscle length tension relationship

Optimal overlap of actin and myosin filaments allows for maximum force production displaying the amount of force a muscle can produce is dependent on the length of the muscle when it begins contracting.

The____of the neuron recieve impulses and send them too the cell body, the_____ carries the impulses from the cell body to another neuron or target tissue.

dendrites, axon

______ is an enzyme in the head of myosin which breaks down ATP and staining of this enzyme can be used to determine muscle_____

Myosin, Fiber type

Muscle contractions is regulated by______, which was once bound to______ induces a conformational changes and pulls tropomyosin from the active site on actin.

calcium, troponin

common formula for estimating HRmax is:

220 - age in years = maximum heart rate