10 - Biology unit 4 human circulatory system

3 part of the system

3 part of the system

heart, blood vessels, and blood

what the total length of all the blood vessels in a person's body?

100 000 km long

function of the circulatory system

acts as a transportation system for moving substances around within the body

what does the circulatory system transport and where? (5)

1. nutrients (e.g. monosacs, amino acids) from the small intestine to all cells

2. oxygen from the lungs to all cells

3. carbon dioxide from all cells to the lungs

4. urea (a waste in the liver) to the kidneys where it is filtered out of the blood to form a part of urine

5. hormones from endocrine glands to all cells

3 main types of blood vessels and what they do

1. arteries - carry blood away from the heart

2. veins - carry blood towards the heart

3. capillaries - tiny blood vessels that carry blood from the arteries to veins

interstitial fluid (3)

• watery liquid that all cells of the body are bathed in (11 liters)

• to pass between the body cells and the blood, all materials (oxygen, carbon dioxide, water, nutrients) must pass through it

• consist of water, salts, proteins, and nutrients

closed circulatory system

blood is always found in the heart or blood vessels

heart valves

act like turnstiles to prevent blood from flowing backwards

what type of circulatory system do humans have?

closed circulatory system

the heart (4)

• pumps blood throughout the circulatory system

• it is made mostly of cardiac muscle

• it is in the thoracic cavity (chest cavity)

• the heart is a double pump

what type of blood does the right side of the heart have and where does it send blood to?

it sends deoxygenated blood to the lungs

what type of blood does the left side of the heart have and where does it send blood to?

it sends oxygenated blood to the body

thoracic cavity

chest cavity

pericardium

tough sac that covers and protects the heart

define:

a) peri

b) cardium

a) around

b) relating to the heart

4 chambers of the heart

right atrium, left atrium, right ventricle & left ventricle

septum

the wall that separates the right and left sides of the heart

define lub-dup (3)

• as the heart valves close they make a sound that can be heart through a stethoscope

  • lub is the closing if the tricuspid and bicuspid valves

  • dup is the closing of the semilunar valves

2 main period of the heart pumping

diastole & systole

define diastole

when the heart muscle is relaxed

define systole

when the heart is contracted

in what order do the chambers conract

first the atria contract and then the ventricles contract

SA node (pacemaker) (3)

• sinoatrial node

• found in the upper wall of the right atrium

• maintains the heart pumping rhythm by setting the rate at which the heart contracts

AV node (3)

• atrioventricular node

• found at the base of the right atrium

• these cells have long projections that pass down into the walls of the ventricles

two small regions of the heart that have the special muscle cells with the built-in ability to contract

sinoatrial node and atrioventricular node

cardiac muscle has a built-in ability to…

contract

What is the smallest blood vessel?

capillaries

blood pressure (4)

• blood pushes against the inside wall of blood vessels

• decreases as blood moves further away from the heart

• pulse is the bulging of arteries that occurs during systole

• blood is moved through veins when the skeletal muscle on either side of a vein contact

what does coronary circulation do? (3)

• it supplies blood to the heart

• the coronary arteries branch to form arterioles and the capillaries

• the coronary veins drain the blood directly into the chambers of the heart

which of the two types of heart chambers has thicker walls?

the ventricles

which heart chambers contract first?

the atria

what is a special ability of cardiac muscle?

it can keep beating after being removed if it is in a certain substance

what are the two special muscle regions in the heart?

the atrioventricular node and the sinoatrial node

how do the nodes help the heart beat?

1. the SA node sends out an electrical signal, causing the atria to contract

2. when the signal reaches the AV, it causes the ventricles to contract