8.1: structurees of the circulatory system

What is the main purpose of the circulatory system?

To transport materials through the bloodstream to different organs

What are the 3 main functions of the system?

Transport, regulate and protect

What does the bloodstream transport around?

Gases, nutrients molecules and waste from other systems

What does the circulatory system regulate?

Temperature by directing blood flow to retain or release heat

Why do hormones travel in the blood?

The bloodstream is the most efficient transport system for chemical messengers

What does the bloodstream protect?

Any blood loss from injury or bacteria entering body

How does the heart help the flow of blood?

It pushes blood through vessels when it beats/contracts

What are the blood vessels job?

The roadway blood moves in around the body

What is bloods main job?

Transport needed substances to body, fight infections and regulate temperature and pH

What are the main components of the circulatory system?

The heart, blood vessels and blood

What are the different blood vessels?

Artists, veins and capillaries

What does the arteries do?

Carry’s blood away from the heart

When do arteries carry oxygen-rich blood away from heart?

In the the Systemic and coronary pathways

When does artie’s carry oxygen-poor blood away from heart?

In the pulmonary- to the lungs

What way do veins carry blood?

Towards to heart

Besides systemic, what other pathway do veins move oxygen-poor blood to heart?

Coronary pathway: both blood streams have waste products

When is the only time veins hold oxygen-rich blood?

In the pulmonary vein from lungs to LA

Why do veins only have one way valves?

To keep blood flowing to heart against gravity

What blood vessel is elastic?

The arteries: allows them to expand and pump blood on their own

Why are capillaries the link between an artery and vein?

The exchange site for arteries to give oxygen/nutrients and veins to pick up the waste

Where does the SA node stimulate contracts of heart?

Sends a signal through two atria, plus another node and down the bundle of his

What is the AV node?

What atrioventricular node receives a signal from the SA node and sends it to the bundle of his

What fluid filled sac reduces friction?

The pericardium between the heart outwall and membrane

What is muscle tissue of the heart?

It’s made up of myocardium

What four parts is the heart sectioned into?

L+R atria, L+R ventricle

What does the valves of the heart do?

Prevent backflow of blood between ventricles and atrias

What side of the heart circulates pulmonary?

The right side: carries blood to and from lungs and body

Where does the left side of the heart carry blood to?

Vessels carry it to the body: called the systemic circulatory system

Which vena cava collects blood from upper body?

Superior vena cava: flows it into right atrium

Where does lower body blood enter into heart?

In the inferior vena cava into the RA

Where does right atriums blood supply come from?

The superior and inferior Vena cava: responsible for collecting body blood

What does the right ventricle do?

Gets blood from RA to pump to lungs

How does the RA pump oxygen rich blood to lungs?

Via the pulmonary artery’s

What is the middle wall separating L+R?

Interventricular septum (thick wall)

Where does the left atria get its blood?

Through pulmonary artery from the lungs

What does the largest artery carry away?

The aorta transports oxygenated blood to body

What does the AV valve do?

The tricuspid prevents backflow of blood between atria and ventricles

What prevents the backflow of blood out of the ventricles?

Semilunar valves (SLV) and the aortic valve on the right side

What does the left AV valve do?

Prevents backflow of blood between ventricles and atria on the left side

What is the flow of blood on the right side?

Body = S+I vena cava = RA = Tri V= RV = SLV = PA= Lungs

What is the order of blood flow on the left side of heart?

Lungs = PV = LA = BiV =LV = SLV = Aorta = Body

How does a heart contracts get recorded?

An electrocardiogram is a device that measures its activity

What controls blood pressure?

When blood moves in vessel, pressure put on walls changes

What is systolic pressure?

The maximum pressure when ventricular contractions happen

What happens before ventricles contract?

Diastolic pressure occurs, its at the lowest pressure

What happens when heart rate increases?

The ventricles push more blood through = higher blood pressure

Why is a low resting heart rate and large stroke volume good?

Means heart can maintain a good cardiac output without strain

How does stroke volume and cardiac output work?

Indicates how much blood is pumped out of heart to make body work