The Cardiovascular System

Flashcards for Unit 2 Quiz 3

primary roles of the cardiovascular system

- To transport oxygen from the lungs to the tissues and to transport carbon dioxide from the tissues to lungs
- To transport nutrients from the digestive system to the other areas in the body and to transport waste products from sites of production to sites of excretion.
- Thermoregulation (constant body temperature)
- Prevention of infection

the heart

a double pump divided into right and left by the interventricular septum

right heart

pumps deoxygenated blood to the lungs (pulmonary circulation)

left heart

pumps oxygenated blood to the rest of the body (systemic circulation)

arteries

carry blood away from the heart

veins

carry blood towards the heart

arterioles

regulate blood distribution to various tissues of the body

capillaries

responsible for the exchange of gases and nutrients with the tissues

coronary circulation

blood is supplied to the cardiac muscle tissue through arteries, arterioles, and capillaries

lub

closing of atrioventricular valves

dub

closing of semilunar valves

blood pressure

the force exerted by the blood against the walls of the arteries

systolic

pressure observed in the arteries contraction phase, when the pressure lessens to a point where blood flow continues, and you hear the first sound

diastolic

pressure observed in the arteries during relaxation phase, once the sound stops completely and blood continues to flow as normal

normal BP

120mmHg over 80mmHg

hypertension

greater than 140mmHg over 90mmHg

factors affecting BP

diet, hydration, training, response to stimuli

plasma

fluid component of blood (mostly water)

red blood cells

transport O2, CO2, nutrients, and waste in the blood

white blood cells

destroy foregin elements, are critical in the function of the immune system

platelets

regulate blood clotting

hemoglobin

protein composed of globin and heme that gives red blood cells their characteristic color

excitation of the heart

The cardiac muscle cells are excitable, and with electrical stimulation they contract. The contraction of the heart leads to the pumping of blood

SA node

where electrical signals are initiated, leading to the contraction of the heart. AKA the heart’s “pacemaker”

basic electrical signal path

SA Node --> AV Node --> Bundle of His --> Right and left bundle branches --> Purkinje fibres

cardiac output (Q)

the volume of blood pumped of the left ventricle in 1 min

heart rate (HR)

the number of times the heart beats in 1 min (bpm)

stroke volume (SV)

the volume of blood ejected by the left ventricle per beat

effect of training the heart

ventricular walls become thicker and volume of blood within the ventricle increases (more forceful contraction)

skeletal muscle pump

each contraction compresses the veins, making the blood flow towards the heart

thoracic pump

difference in pressure pushes blood from veins in the abdominal cavity into veins in the thoracic cavity

the nervous system

Sends a signal to veins --> veins constrict, forcing more blood back to the heart

effect of training on blood

increases blood volume, which creates more RBC and increased Q

bradycardia

abnormally slow heartbeat (less than 60bpm)