🫀 12 circulatory system

open vs closed circulatory system? (12.1)

• open system blood flows freely within body cavity

• closed system blood is physically contained within vessels

what are blood and fluids called in invertebrates? (12.1)

hemolymph

three components of circulatory system? (12.1)

heart, blood vessels and blood

why are pulmonary arteries an exception to other arteries? (12.1)

they carry deoxygenated blood (from right ventricle to lungs) , compared to arteries regularly carrying oxygenated blood

where do veins bring deoxygenated blood towards? (12.1)

towards the heart

what type of blood do arteries carry, and to where? (12.1)

oxygenated blood away from the heart to tissues

how does blood get back to the heart? (12.1)

through valves (one-way)

what happens when veins don’t work properly? (12.1)

they become varicose, and blood pooling occurs → veins become larger and begin to bulge

• caused by prolonged standing with restricted movement

two main proteins in plasma? (12.1)

• fibrinogen (helps with blood clotting)

• globulins (antibodies/immune)

scientific name of red blood cells + their function?

erythrocytes

• specialized for transport oxygen

• no nucleus

• each has lots of hemoglobin

scientific name of white blood cells + function? (12.1)

leukocytes

• responds to infection, part of immune system

• has nuclei and appears colourless

• some undergo phagocytosis —> engulf and destroy pathogens

scientific name of platelets + function? (12.1)

thrombocytes (clotting blood to prevent blood loss after an injury)

• no nuclei

what is the path that blood follows with pulmonary circulation? (12.1)

heart —> lungs —> heart

what is cardiac circulation? (12.1)

movement of blood through heart tissues

what path does blood follow with systemic circulation? (12.1)

heart —> body —> heart

how does blood flow through the heart? (12.1)

• deoxygenated blood (from the body) enters through the superior and inferior vena cava into the right atrium, through the tricuspid valve into the ventricle

  • it then leaves through the pulmonary valve and pulmonary arteries to enter the lungs

• oxygenated blood enters through the pulmonary veins into the left atrium, through the mitral valve into the ventricle

  • it leaves through the aortic valve and aorta to the rest of the body

difference between superior and inferior vena cava? (12.1)

• superior vena cava collects deoxygenated blood from tissues in head, chest and arms

• inferior vena cava does the same but from other parts of the body

why are pulmonary veins an exception to other veins? (12.1)

they carry oxygenated blood (from lungs to heart), compared to veins regularly carrying deoxygenated blood

what are the names of the two atrioventricular valves + why are they called those names? (12.1)

• the one on the right is called tricuspid valve as it has three flaps

• the one on the left is called bicuspid (mitral) valve as it has two flaps

what are the other two valves aside from the atrioventricular ones called? (12.1)

semilunar valve (their half-moon shape)

• pulmonary and aortic valve

where do red, white blood cells and platelets originate from? (12.1)

red = red bone marrow

white = red bone marrow

platelets = red bone marrow, lungs

relative size of red, white blood cells and platelets? (12.1)

red = small

white = large/largest

platelets = smallest

lifespan of red blood cells? (12.1)

120 days

lifespan of white blood cells? (12.1)

few hours-days

lifespan of platelets? (12.1)

2-8 days

what is the widening of blood vessels called, and when does it occur? (12.1)

vasodilation

• occurs as a result of vigorous activity or high external temperature

• helps to release heat

what is the narrowing of blood vessels called? (12.1)

vasoconstriction

• helps to conserve heat

two factors that can stimulate vasodilation or vasoconstriction? (12.1)

blood pressure (vasodilation will reduce if its too high, vasoconstriction will increase if its too low) and exercise (vasodilation to increase blood flow)

what is the “pacemaker” in the heart? (12.2)

sinoatrial (SA) node

• 
  

how to determine cardiac output? (12.2)

cardiac output = heart rate x stroke volume

arrange as needed

what are some factors that can contribute to high blood pressure? (12.2)

• genetics

• physical activity

• stress

• diet

• body temperature

• medication

how is blood pressure measured? (12.2)

an arm artery is selected to be measured with a sphygmomanometer (blood pressure cuff)

describe the meaning of the two numbers that represent blood pressure? (12.2)

120/80

systolic maximum pressure during ventricular contraction

diastolic lowest pressure before ventricles contract again

blood pressure stages (reference)

what is an electrocardiogram (ECG) + its purpose? (12.2)

a test that measures slight voltage changes that occur as the heart contracts and relaxes

• important for detecting changes in the heart that may be harmful