79 terms


Smooth Muscle
non-striated, long spindle like structure, involuntary, one nucleus
Skeletal Muscle
striated, cylindrical, voluntary, multinucleated
Cardiac Muscle
striated, interwoven fiber arrangement, one nucleus, located in heart
Components of Skeletal Muscle
muscle belly, muscle fiber bundle, muscle fiber, myofibril
Microstructure of Muscle Fibers
myofibrils, sarcomere, sarcoplasmic reticulum, transverse tubules
actin (thin filaments) & myosin (thick filaments)
includes Z line, M line, H zone, A band, I band
Sarcoplasmic Reticulum
storage sites for calcium and terminal cisternae
Motor Unit
a group of fibers activated via the same nerve; all muscle fibers of one particular motor unit are always of the same fiber type
Intramuscle Coordination
the capacity to apply motor units simultaneously; force deficit
Intermuscle Coordination
the interplay between muscles that generate movement through contraction (agonists) and muscles responsible for opposing movement (antagonists)
Motor Unit Recruitment Process
recruitment of muscle fibers during resistance work depends on the level of muscle tension; as tension rises more and more of the various fiber types are recruited into the movement
Skeletal Muscle Functions
force production for locomotion and breathing, postural support, and heat production during cold stress
Muscle Spindles
a stretch receptor that sends signals to the spinal cord then to synapse with alpha motor neurons and causes the muscle to contract and resist being stretched; signal agonist
Golgi Tendon Organ
sensitive to tension and force that synapses with inhibitory neurons that synapse with alpha neurons and cause relaxation relieving the tension applied to the tendon; functions to protect the muscle from too much stretch
Static Contraction
a contraction in which the muscle tension or internal force against an external load is equal or weaker than the external load; no visible movement of external load occurs
Isometric Contraction
a static contraction in which there is no visible change in muscle length, even though the muscle has undergone muscle contraction; no work (work=force x distance) performed but energy is used
Dynamic Muscle Contraction
muscle tension or force is exerted against an external load;internal force is greater than the external load so movement of external load occurs
Isotonic Contraction
during dynamic work, continual changes in joint angle and speed result in changes in strength needs; constant addition or subtraction of motor units recruited causes the muscle to adapt to constantly changing tension requirements (iso=same or constant and tono=tension)
Isokinetic Contraction
a dynamic contraction that involves a constant speed contraction against a preset high resistance (iso=same or constant and kinetic=motion)
Plyometric Contraction
a hybrid contraction in that the muscle performs an isotonic concentric contraction from a stretched position
Concentric Contraction
muscle shortens as it goes through a range of motion; usually termed flexion
Eccentric Contraction
muscle lengthening during movement; usually termed extension
Maximal Strength or Absolute Strength
the total amount of weight you can lift at one time
Relative Strength
the performance of athletes classified by wight or athletes who must overcome their own body mass depends less on maximal strength than on the proportion of maximal strength to body mass (relative strength= maximal strength/ body mass)
the ability to overcome external resistance by developing a high rate of muscular contraction; also known as speed-strength
Muscular Endurance
the ability to resist fatigue in strength performance of longer duration; also known as strength endurance
aging affects muscle force output, a loss of fast-twitch fibers, may occur as a result of apoptosis, may occur as a result of disuse
the absolute force and power capacity of women is often less than that of men due to the difference in muscle volume
Fast Twitch Fibers
fast glyolytic and fast oxidative;significantly greater force and speed generating capability , fatigue faster, more anaerobic
Ex. sprinting
Slow Twitch Fibers
slow oxidative; suited for repeated contractions during activities requiring a force output of less than 20-25% of max force output, rely on oxygen
Ex. endurance activities
Sliding Filament Theory
the sliding of the thin actin filaments over the thick myosin filaments that causes shortening of the muscle to create movement
force deficit
the difference between assited and voluntarily generated maximal force
Factors that Affect Force Production
joint angle, muscle cross-sectional area, speed of movement, muscle fiber type, age, and sex
Joint Angle
the type of contraction and the force required to resist an external load as it changes at different joint angles
Muscle Cross-sectional Area
body mass is positively correlated with strength, provided that the mass is primarily muscle tissue or lean mass; the larger the muscle cross-sectional area, the more force it can generate
Speed of Movement
as the speed of movement is increased, the force that the muscle can develop is decreased
Relationship Between Maximal strength and Power
hormone testosterone must be present
another hyperichy factor is?
fiber type
medical term for muscle loss
Aerobic Metabolism
energy or ATP production in the presence of oxygen
Anaerobic Metabolism
energy or ATP production without the presence of oxygen
Phosphagen System
energy production for muscular activity fueled by immediate ATP and creatine phosphate muscle stores;has a limited supply therefore the duration of an activity is short, but it produces very large amounts of energy within a short period of time rate of recovery is rapid; yields 1 ATP
Anaerobic Glycolytic System
results in lactic acid build up; can produce energy without the presence of oxygen, energy production for muscular activity is fueled by stored glycogen and blood glucose; yield 2 ATP but it takes longer to produce thus slowing a person down
a biochemical process that releases energy in the form of ATP from glycogen and glucose; anaerobic process
primary energy fuels for brain, muscles, heart, and liver; most important fuel source for body during exercise
Aerobic Oxidative System
energy production for muscular activity is fueled by glycogen, glucose, fats, and proteins but takes longer to use fat for energy
fat molecule= glyceroc+3 fatty acids
the power house; anaerobic metabolism takes place here; increase in mitochondria= increase in work
Metabolic limiting factors
the system requires continuous and adequate supplies of oxygen and fuel sources that are necessary for aerobic metabolism and the rate of ATP utilization must be relatively slow to allow the process to meet the energy demands
Primary Roles of the Cardiovascular System
transport oxygen from the lungs to the tissues, carbon dioxide from the tissues to the lungs, nutrients from the digestive system to other areas in the body, and waste products from sites of production to sites of excretion
Heart Structure
consists of four chambers: two ventricles and two atria
pump blood through the body
receive blood from peripheral organs and pump blood into the ventricles
Left Ventricle
pumps blood through the entire body
Right Ventricle
pumps blood a short distance to the lungs
Blood Pressure
an important measure of cardiac function
Two Components of blood pressure
diastole and systole
describes the pressure in the heart when the ventricles are relaxed and being filled with blood
the pressure in the ventricles when they are contracting and pushing blood out into the body
Stroke Volume
the amount of blood pumped out of the left ventricle each time the heart beats
Cardiac Output
the amount of blood that is pumped into the aorta each minute by the heart
Heart Rate
the number of times the heart beats in one minute, measured in beats per minute (bpm)
vessels that carry blood away from the heart
arteries that branch into smaller and smaller vessels
the arterioles that branch into even smaller vessels
allow the exchange of oxygen and nutrients from the blood to muscles and organs and also allows blood to pick up waste products and carbon dioxide from metabolism
as the blood begins to return to the heart, capillaries connect to form larger and larger vessels
venules that merge into larger vessels that return blood to the heart
Primary role of the respiratory system
deliver oxygenated air to blood and remove carbon dioxide from blood, a by product of metabolism
Components of Respiratory System
lungs, several passageways leading from outside to the lungs, and muscles that move air in and out of the lungs
located in the thoracic cavity/chest; the right side is larger than the left side because the heart takes up more space on the left side
Conduction Zone
a set of anatomical structures through which air passes before reaching the respiratory zone
Conduction Zone Components
bronchi, bronchioles, and terminal bronchioles
Conduction Zone Breakdown
the trachea branches into right and left bronchi that enter the lungs and continue to branch into smaller and smaller tubes called bronchioles, and finally terminal bronchioles
Respiration Zone
the region where gas exchange occurs
the functional units of the lungs are the tiny air sacs
Alveolar Sae
a cluster in bunches like grapes with a common opening into an alveolar duct
the primary muscle responsible for passive respiration