Biology - Circulatory system

What is the function of the circulatory system?

• Transport oxygen, nutrinets, hormones, and waste.

• Regulate body temperature

• Defend against infection

What are the three main parts of the circulatory system and their function

• Heart : Muscular organ that continously pumps blood throughout the body

• Blood vessels: system of hollow tubes through which blood moves

• Blood: fluid that transports materials throughout the body

Arteries: Structure + Function

Function: carry blood away from the heart

Structure: thick, muscular walls.

Veins: Structure + Function

Function: Carry blood towards the heart

Structure: Thinner walls, have valves to prevent back flow

Capillaries: Structure + Function

One cell wall thick; connects arteries to veins

What are the components of blood + their function?

• Plasma: Carry nutrients, hormones, and waste.

• Platelets: Help in blood clotting

• RBC’s: Carry O2

• WBC’s: Fight infections

What are the 4 chambers of the heart?

Right atrium: recieves deoxygenated blood from the body

Right ventricle: Pumps it to lungs via pulmonary artery

Left atrium: recives oxygenated blood from lungs

Left ventricle: pumps it to body via aorta

What is the blood flow in the heart?

• the vena cava brings oxygen poor blood from the body to the right atrium

• the oxygen poor blood flows from the right atrium to the right ventricle

• the right ventricle pumps the oxygen poor blood to the lungs through the pulmonary arteries

• the pulmonary veins bring oxygen rich blood from the lungs back to the heart through the left atrium

• the left ventricle pumps the oxygen rich blood to the body through the aorta

What causes the lub sound in a heartbeat?

caused by the closing of the atrioventricular valves as blood is pumped from atria to the ventricles

What causes the dub sound in a heartbeat?

caused by the semilunar valves, as blood is pumped from ventricles into the arteries.

What are sphincters in the heart?

Ring like muscles that regulate blood flow into the capillary beds

What do the valves in the heart do?

they ensure. one way blood flow in veins and heart, preventing backflow

What is the surface area in the circularoey system?

• made up of cappillaries - together they create a large surface area for gas exchange and nutrient and waste exchange.

What is a pulse?

Number of heartbeats per minute

What is blood pressue?

force of blood against artery walls

What is systolic?

Pressure during heart contraction? (top number)

What is diastolic?

Pressure during heart relaxation (bottom number)