Ex phys exam 2 first part + heart topics

direct vs indirect calorimetry

Direct calorimetry measures heat production and indirect calorimetry measures gas exchange

direct MEASURES heat production and indirect ESTIMATES it

VO2 vs VCO2

VO2: volume of O2 (oxygen) consumed per minute

VCO2: volume of CO2 (carbon dioxide) produced per minute

Respitory Exchange Ratio (RER)

the ratio between the volume of CO2 produced and the amount of O2 consumed

RER=VCO2/VO2

Basal Metabolic Rate (BMR)

amount of energy (cals) to maintain basic bodily functions at rest

Resting Metabolic Rate (RMR)

The rate at which the body expends energy (calories) at rest

VO2 Max test

Highest amount of O2 an individual can take in &utilize during exercise

stoppage criteria for VO2 max test

1. participant tells you they have to stop

2. they fall off the treadmill

3. plateau in oxygen consumption

trained vs untrained

trained people will have a higher VO2 max then untrained. They can utilize more oxygen for a longer period of time.

Functions of the heart

Delivers O2 and nutrients•

Removes CO2 and other waste

• Transports hormones and other molecules

• Supports temperature balance and controlsfluid regulation•

Maintains acid-base balance•

Regulates immune function

Circulatory elements

1.Pump

2. Channels or Tubes

3. Fluid medium

Myocardium

cardiac muscle

What is the significance of intercalated discs?

They connect cardiac muscle fibres together.

Anatomy of Heart

Blood flow through heart/lungs/body

deoxygenated blood from the body enters the heart, is pumped to the lungs for oxygenation, and then oxygenated blood returns to the heart to be pumped out to the body

where does blood go when it leaves the right ventricle?

pulmonary valve to pulmonary artery

oxygenated vs deoxygenated

oxygenated rich in oxygen brighter red color

deoxygenated low in oxygen darker red color

Process of electrical conduction

1. SA node initiates contraction signal

2. AV node delays, relays signal to ventricle

3. AV bundle relays signal to RV, LV

4. Purkinje fibers send signal into RV, LV

Polarization, depolarization , repolarization

polarization is heart muscle cells at rest

depolarization is an electrical process that initiates the contraction of the heart muscle

repolarization heart muscles return to resting state after contraction

pacemaker

the hearts pacemaker is known as the SA Node

ECG

recordings of heart's electrical activity

3 phases:

P wave- activation of atria

QRS complex- activation of ventricles

T Wave

Control of Heart Rate

-Parasympathetic activity slows heart rate; (vagus nerve)

sympathetic activity increases heart rate

(cardiac accelerator nerve)

Cardiac Cycle

All mechanical and electrical events occurring during one heartbeat

Stroke Volume

volume of blood pumped in one heart beat

End Diastolic Volume (EDV)

Volume of blood in the ventricles after diastole

End Systolic Volume (ESV)

Volume of blood in the ventricles after systole

Ejection Fraction (EF)

% of EDV pumped

normal % at rest is 60%

Q: at rest vs excercise

at rest q= 5 L/min

during exercise q=25 L/min

VC (vasoconsriction)

the narrowing of blood vessels

vasodialation

blood vessels widen

Systolic Pressure (SBP)

highest pressure in artery- top # when taking blood pressure

diastolic pressure (DBP)

lowest pressure in artery- bottom # when taking blood pressure

Mean Arterial Pressure (MAP)

Average pressure over entire cardiac cycle

Pressure differences in each type of blood vessel (veins vs arteries)

arteries= high BP

veins = low BP

what maintains/ controls BP?

barorecpeters and chemoreceptors

How blood flow changes based on need

The organs need more blood when exercising compared to when at rest

Functions of blood

1. trasnportation

2. temperature regulation

3. Acid- base (pH) balance

components of blood

55-65% plasma

40-45% forced elements

hematocrit=total percentage of volume composed of formed elements

What causes changes in Plasma?

dehydration and physical activity

What is the function of coronary arteries?

provide main blood supply to the heart