Studied by 7 people3 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)
nutrients (e.g. monosacs, amino acids) from the small intestine to all cells
oxygen from the lungs to all cells
carbon dioxide from all cells to the lungs
urea (a waste in the liver) to the kidneys where it is filtered out of the blood to form a part of urine
hormones from endocrine glands to all cells
3 main types of blood vessels and what they do
arteries - carry blood away from the heart
veins - carry blood towards the heart
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?
the SA node sends out an electrical signal, causing the atria to contract
when the signal reaches the AV, it causes the ventricles to contract
Note
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