KINES 314 UW-Madison Exam 2

circulatory system

(aka cardiovascular system) This system works as the transportation highway for the body. It consists of the heart, blood, and blood vessels. It transports substances such as oxygen, carbon dioxide, and nutrients in the body.

how does the circulatory system maintain homeostasis

exercise

gravity

temperature

oxygen consumption

sleep

how does the circulatory system maintain balance competition

metabolic demand and blood pressure

characteristics of the circulatory system

adaptable

durable and delicate

durable characteristic

the heart never rests

arteries and arterioles

carry blood away from the heart

capillaries

exchange sites for o2, co2 and nutrients with tissues

how many circuits does the cardio respiratory system have

two- pulmonary and circulatory

how many pumps does the cardio respiratory system have

two- right and left

what does the cardio respiratory system control

directional flow and differing o2 profiles

what side of the heart is the pulmonary circut

the right side

what does the pulmonary circuit do

pumps deoxygenated blood to the lungs and returns oxygenated blood to the left side of the heart

what does the systemic system do

pumps oxygenated blood to the whole body and returns deoxygenated blood to the right side of the heart.

what side of the heart is the systemic ciruit

left

mean arterial pressure is

100 mmhg

electrical activity

automatic and connected by intercalated discs

contractile processes

calcium induced contractions and calcium released

regulation of contraction

sympathetic stimulaltion

what happens to circulatory system balance during exercise

the skeletal muscle increases in metabolic demand and cardiac ouput must increase to match demand

contraction of the heart depends on what

electrical stimulation of the myocardium

sinoatrial node

pacemaker initiates depolarization

atrioventricular node

passes depolarization to the ventricles with a brief delay allowing for ventricalar filling

bundle branches

they are located on the left and right ventricles

purkinje fibers

located throughout the ventricles

electrocardiogram

records electrical activity of the heart

P wave

atrial depolarization

QRS complex

ventricular depolarization and atrial repolarization

T wave

ventricular repolarization

ECG abnormalities indicate what

cardiovascular disease

bradycardia

slow heart rate

tachycardia

fast heart rate

how to determine variation with an ecg

r-r interval

athlerosclerosis

fatty plaque that narrows arteries

myocardial ischemia

decreased blood flow to myocardium

s-t segment depression

suggests myocardial ischemia

during diastole is the pressure high or low in the ventricles

low- they are filling with blood from the atria

during systole what happens to pressure in the ventricles

it rises, the blood ejected in pulmonary and systemic circulation

systolic pressure

pressure generated during ventricular contraction

diastolic pressure

pressure in the arteries during cardiac relaxation

pulse pressure

difference between systolic and diastolic

mean arterial pressure

average pressure in the arteries

wiggers diagram

relates electrical events of heart cycle to the mechanical, pressure, and sound changes that occur during a cardiac cycle

what determines mean arterial pressure

cardiac ouput and total vascular resistance

short term regulation of blood pressure

Sympathetic nervous system

Baroreceptors in aorta and carotid arteries

long term regulation

kidneys- control blood volume

during exercise what happens to MAP

increases slightly, CO increases and TPR decreases

what is cardiac output

the amount of blood pumped by the heart each minute

regulation of heart rate parasympathetic

vagus nerve- slows hr by inhibiting SA and AV node and Acetylcholine to muscarinic receptors

regulation of heart rate sympathetic

cardiac accelerator nerves- increases heart rate by stimulating the sa and av nodes

why do athletes have a lower heart rate

due to elevated parasympathetic tone

the initial increase in heart rate is caused by

parasympathetic withdrawl- up to 100 beats/min

beta-adrenergic blocking drugs

compete with epinephrine and norephinephrine for beta adrenergic receptors of the heart

beta adrenergic drugs do what to the heart

reduce HR

reduce contractility

lower myocardial O2 demand

Lower CO

preload

volume of blood in ventricles at end of diastole

afterload

the amount of resistance to ejection of blood from the ventricle

end diastolic volume

volume of blood in the ventricles at the end of diastole

factors that play a role in end diastolic volume

venous return- frank starling mechanism

Frank-Starling Law of the Heart

the more the heart fills with blood during diastole, the greater the force of contraction during systole

how is venous return increased?

venoconstriction, skeletal muscle pump, respiratory pump

venoconstriction is caused by

sns

skeletal muscle pump

rythmic skeletal muscle contractions force blood in the extremities towards the heart

how does sympathetic stimulation effect cardiac output

it increases it.

hematocrit

percentage of blood composed of cells

how does blood viscosity change

increased red blood cells- hematocrit

temperature

clotting

dehydration and

blood doping

hypertension

140/90

hypertension is a risk factor for

Left ventricular hypertrophy

Atherosclerosis and heart attack

Kidney damage

Stroke

what does exercise do for blood pressure

increases venous return and highers blood pressure

what does resistance depend upon

1. length of vessel

2. viscosity of blood

3. radius of vessel

pressure changes across circuit

aorta- high

veins- low

arterioles- largest pressure change

terminal arterioles

arterioles that have one complete layer of smooth muscle cells that control blood flow to the capillaries

Guyton Basic Theory of Circulation

The rate of blood flow to each tissue is almost always precisely controlled in relation to tissue need

Autoregulatoin

blood flow increased to meet metabolic demands of tissue

vasoconstriction to visceral organs and inactive tissues during exercise

blood flow reduced

where is nitirc oxide produced

in the endothelium and promotes smooth muscle relaxation resulting in vasodialation

cellular respiration

the process by which cells use oxygen to produce energy from food

pulmonary respiration

ventilation (breathing) and the exchange of gases (O2 and CO2) in the lungs

purposes of respiratory system

-Gas exchange between the environment and the body

-Regulation of acid-base balance during exercise

respiratory zone

exchange of gases between air and blood

expiration is passive at rest

T/F

true

airflow depends on

pressure difference and resistance of airway

tidal volume

amount of air moved per breath

breathing frequency

number of breaths per minute

alveolar ventilation

volume of air that reaches the respiratory zone

dead space ventilation

volume of air remaining in conducting airways

how does breathing frequency change with exercise?

it becomes faster and wave lengths become equal

where does blood flow in the lungs

when standing- to the base of the lung

during exercise where does blood flow to the lungs

the top apex

ventilation perfusion ratio

the ratio between ventilation and perfusion in the lung; matching of ventilation to perfusion optimizes gas exchange

what does exercise do to the ventilaiton perfusion ratio

improves it unless in heavy exercise then it results in equality

daltons law

The total pressure of a mixture of gases is the sum of the individual pressures (Ptotal=P1+P2+P3...)

Fick's Law of Diffusion

The rate of gas transfer (V gas) is proportional to the tissue area, the diffusion coefficient of the gas, and the difference in the partial pressure of the gas on the two sides of the tissue, and inversely proportional to the thickness.

hemoglobin dissociation curve

shows that a small change in the partial pressure of oxygen can result in a large change in delivery of O2

Bohr effect

a decrease in the amount of oxygen associated with hemoglobin and other respiratory compounds in response to a lowered blood pH resulting from an increased concentration of carbon dioxide in the blood.

Bohr Effect and Temperature

increase in blood temperature lowers hemoglobin oxygen affinity

how does the dissociation curve shift for muscle unloading

right- high temperature and low ph

how does the dissociation curve shift lung loading

left- return to a cooler temp and normal ph

myoglobin

stores oxygen in muscle cells

base

decreases hydrogen concentration and decreases ph

lactic acid is a strong acid t/f

true

the ph of water is 7.0

basic