flashcards

Question 1

The active binding sites to which myosin cross bridges attach during muscle contraction are found on the

Answer 1

Actin filaments

Question 2

When a muscle fiber is stimulated by a motor nerve, the muscle fiber either will contact maximally or it will not contract at all.

Answer 2

All or none principle

Question 3

The structure within skeletal muscle that spreads the nerve impulses rapidly throughout individual myofibrils

Answer 3

T tubules

Question 4

The muscle that provides most of the force required for a movement

Answer 4

agonist

Question 5

The specialized network of membranous tubules that stores calcium ions in a muscle fiber

Answer 5

Sarcoplasmic reticulum

Question 6

The thick filaments of a myofibril are composed mainly of

Answer 6

Myosin

Question 7

The muscle fiber that constitutes for approximately 50% of the total muscle fibers in most muscles of the body, in the normal, non athletic population.

Answer 7

Type I fibers

Question 8

A muscle action in which the muscle generates force but does not change in length

Answer 8

Isometric contraction

Question 9

low oxidative capacity, high glycolytic capacity, fast contraction speed, and a low level of fatigue resistance are characteristics of

Answer 9

Type II fibers

Question 10

The striated appearance of skeletal muscle fiber is mainly due to the arrangement of

The A-band of a sarcomere contains

Answer 10

Actin and Myosin myofilaments

primary contractile proteins in muscles are

Question 11

The muscle lengthens as contractile force is generated

Answer 11

Acentric contraction

Question 12

During a progressive increase in exercise intensity, motor units

Answer 12

with small motor neurons are recruited first

Question 13

The smallest functional unit of a muscle

Answer 13

Sarcomere

Question 14

The process by which free fatty acids are broken down to yield multiple molecules of acetyl COA

Answer 14

Beta oxidation

Question 15

The major source of energy for running a 440 yard race

Answer 15

Carbohydrate

Question 16

The primary source of energy during a marathon is

Answer 16

Oxidative system

Question 17

The two enzymes most commonly measured in order to assess the oxidative capacity of muscle tissues are

Answer 17

Succinate dehydrogenase

Citrate synthase

Question 18

Anaerobic glycolysis begins with either glucose or glycogen and ends with

Answer 18

Lactic acid

Question 19

The major metabolic waste product that causes the muscles and blood to have a lower ph during exercise of increasing intensity is

Answer 19

Lactate

Question 20

represents depolarization of the atria

Answer 20

P wave

Question 21

The volume of blood ejected from the heart with each contraction is called

Answer 21

Stroke volume

SV= ESV-EDV

Question 22

what phase of the cardiac cycle does the diastolic pressure reflect

Answer 22

Relaxation

Question 23

Skeletal muscles receive approximately ___% of the total cardiac output under resting conditions, but they can receive as much as ___% cardiac output during heavy endurance exercise.

Answer 23

15, 80

Question 24

The structures within heart tissue that anchor individual cells together so they do not pull apart during contraction

Answer 24

Desmosomes

Question 25

The volume of blood in the ventricles at the end of ventricular filling is called

Answer 25

End diastolic volume

Question 26

Resistance vessels are also called

Answer 26

Arterioles

Question 27

Represents repolarization of the ventricles

Answer 27

T wave

Question 28

Represents depolarization of the ventricles

Answer 28

QRS complex

Question 29

Mean pressure in the pulmonary artery is

Answer 29

15 mmHg

Question 30

Found in skeletal muscle, serves to transport oxygen from the cell membrane to the mitochondria

Answer 30

Myoglobin

Question 31

A decrease in muscle or blood ph causes increased unloading of 02 from hemoglobin, this is an example of the

Answer 31

Bohr effect

Question 32

States that the rate of diffusion through a tissue such as the respiratory membrane is proportional to the surface area and the difference in the partial pressure of gas between the two sides of the tissue

Answer 32

Ficks Law of Diffusion

Question 33

Regulation of ventilation is complex and regulated by multiple factors. The area responsible for 'switching off' inspiration and helping to regulate inspiratory volume is the

Answer 33

Pneumotaxic center

Question 34

ventilator regulation appears to be most sensitive to which chemical stimuli

Answer 34

pCO2

Question 35

a shortening of inspiration that occurs in response to activation of stretch receptors in the lungs

Answer 35

Hering Breuer reflex

Question 36

States that at a constant temperature, pressure and volume are inversely related

Answer 36

Boyles Law

Question 37

Explains the sum of partial pressures in a mixture of gases

Answer 37

Daltons Law

Question 38

The amount of air remaining in the lungs after a maximal expiration

Answer 38

Residual volume

Question 39

The largest volume of air that can be exhaled after a maximal inspiration is

Answer 39

Vital capacity

Question 40

The carotid bodies are chemoreceptors that are sensitive to changes in arterial

Answer 40

H +, pc02, and p02

Question 41

The amount of air inhaled or exhaled during a given breath is called the

Answer 41

Tidal volume

Question 42

An athlete started taking long cycling rides and bought a heart rate watch to monitor HR. She noticed after about 40 minutes of riding at a steady pace that HR gradually increased without increasing the work output. What is causing the cardiovascular drift since cardiac output is unchanged?

Answer 42

decreased SV

Question 43

Sub maximal exercise tests can be used to estimate aerobic capacity based on

Answer 43

The linear relationship between heart rate and oxygen consumption

Question 44

Which of the following groups of individuals are most likely to experience exercise-induced hypoxemia during exercise?

Answer 44

Olympic marathoners

Question 45

what would cause a decrease in stroke volume?

Answer 45

Exercise | An increase in afterload

Question 46

What is the most important contributor to the improvement in stroke volume with endurance training?

Answer 46

Increase blood volume

Question 47

Resting stroke volume ____ in the supine position.

Answer 47

Increases

Question 48

During a graded exercise test, you would expect to see systolic blood pressure ___ while diastolic blood pressure ____.

Answer 48

rise linearly; changes very little

Question 49

At near-maximal and maximal exercise intensities, ____ is a major determinant of cardiorespiratory endurance capacity.

Answer 49

Stroke volume

Question 50

The tolerable limits for arterial blood pH extend from

Answer 50

6.9 to 7.5

Question 51

What type of muscular contraction is mostly likely to induce delayed-onset muscle soreness (DOMS)?

Answer 51

Eccentric contractions

Question 52

In the trained heart, increased ventricular mass results in ____ EF.

Answer 52

Increased

Question 53

Heart chamber that undergoes the greatest hypertrophy in response to aerobic training

Answer 53

Left Ventricle

Question 54

In response to aerobic training, Type 1 fibers become ____ and Type 2 fibers generally _____.

Answer 54

Larger; | No change

Question 55

Anaerobic 30-second training bouts lead to an increase in

Answer 55

Phosphofructokinase

Question 56

transport is driven by the energy stored in the concentration gradient of another molecule

Answer 56

Secondary Active transport

Question 57

molecules are pumped against a concentration at the expense of energy

Answer 57

Primary Active Transport

Question 58

a substance is transported in same direction as "driver" ion | ex. glucose "piggybacks" onto Na⁺

Answer 58

Co-transport

Question 59

the minimum charge we need to reach for action potential to happen V sub m

Answer 59

RMP

Question 60

electrical charge moves towards positive Na⁺ goes into cell ex. -70 resting potential to -30

Answer 60

Depolarization

Question 61

electrical charge moves towards negative K⁺ leaves the cell ex. +20 to -40

Answer 61

Repolarization

Question 62

electrical charge overshoots and goes below the resting potential ex. -70 to -100

Answer 62

Hyperpolarization

Question 63

A regenerating depolarization of membrane potential that propagates along an excitable membrane

Answer 63

Action potential

Question 64

Opening Na⁺ channels generates local current that depolarizes adjacent membrane, opening more Na⁺ channels - how impulse moves across neuron

Answer 64

Propagation

Question 65

The tendency for turbulent flow increases in direct proportion to the velocity of blood flow, the diameter of the blood vessel, and the density of the blood.

Answer 65

Reynold's number

Question 66

Activate and regulate T and B cells. These cells bind antigenic peptides present on MHC II molecules on APC. Make cytokines to coordinate IR.

Answer 66

CD4+ T helper cells

Question 67

Binds antigens presented by MHC I of virus-infected or tumor cells and kills them. Nearly all nucleated cells display MHC I. These cells also receive an activation signal from helper t-cells.

Answer 67

CD8+ cytotoxic T cells

Question 68

Virus and infected tumor cells that do not display MHC I or display stress.

Answer 68

NK cells

Question 69

Mark pathogen for ingestion and destruction by a phagocyte.

Answer 69

Antibody opsonization

Question 70

Type of APC that present antigens to Cytotoxic T-cells

Answer 70

MHC I

Question 71

What are the steps of hemostasis or when a blood vessel is ripped open?

Answer 71

1. vascular constriction (smooth muscle contracts) 2. Platelet Plug 3. Blood coagulation