Circulatory Systems Quiz Flashcards
(90 cards)
Circulatory Systems:
Transportation system for oxygen, nutrients, and cell waste to move throughout the body
Major Functions
- Transports gases (From the respiratory system) nutrient molecules (From the digestive system) and waste materials (From the executory system)
- Regulate internal temperature & transport hormones
- Protect AGAINST blood loss from injury & AGAINST disease-causing microbes or toxic substances introduced in the body
Major Parts
- 3 Major components:
- Heart: Pushes blood throughout the body with its pumping action & generates blood flow
- Blood Vessels: Serves as PATHWAYS for blood to move
- Blood: CARRIES nutrients, oxygen, carbon dioxide, water, waste and other materials throughout the body
Cardiovascular Systmes
“Cardio” = Heart
“Vascular” = Vessels
The cardiovascular system is the heart & blood vessels
Pulmonary Pathway
Pumped by the RIGHT SIDE of the heart
Transports oxygen-poor blood to the LUNGS
When it gets oxygen from the lungs the oxygen-rich blood is returned through the Pulmonary Veins
Vena Cava –> Right Atrium –> Rigtht AV Valve –> Left Ventricle –> Semilunar Valve –> Pulmonary Artery –> Lungs
Systemic Pathway
Moves oxygen-rich blood from the left ventricle of the heart to the body tissues (Body Systems)
It is pumped by the LEFT side
Pulmonary Veins –> Left Atrium–> Left AV Valve –> Left Ventricles –> Semilunar Valve –> Aorta –> Body
Coronary Pathway
Provides blood to the heart
It is pumped by the left side
Aorta –> Coronary Artery–> Cardiac Veins
Structures of Blood Vessels
Arteries, veins, capillaries
Arteries
- Carry oxygen-rich blood AWAY from the heart
-
Highly elastic walls allow the artery to expand as blood moves through during the contraction of the ventricles and snap back again during the relaxation of the ventricles
Keeps blood flowing in the right direction
Provides a pumping motion to help force blood through the blood vessels [You can feel this when you feel your pulse]- MEMORY TIP: Arteries —> Away (Both start with “A”)
Veins
- Carry Oxygen-poor blood towards the heart
- Thinner walls & larger inner circumference than arteries
- NOT elastic, CANNOT contract to help blood move to the heart, instead muscles help keep the blood flowing toward the heart
- Have one-way valves that prevent blood from flowing backwards
- Muscles RELAXED = Valves CLOSED
- Muscles CONTRACTED = Valves OPEN
Capillaries
- Where gases, nutrients and other materials are transferred to tissue cells and wastes, including gases, move into the blood
- Smallest blood vessels
- Spread throughout the body in a fine network
- The capillary wall is a single layer of cells with a tiny diameter making it so that the blood cells pass through a single file
Pulmonary Artery
Carries deoxygenated blood (Oxygen-poor) AWAY from the heart
INSTEAD of the oxygenated blood arteries usually carry
Pulmonary Vein
Carries OXYGENATED blood (Oxygen-rich blood) to the heart
INSTEAD of the deoxygenated blood veins usually carry.
Heart Beat
Is an electrical signal coming from the heart
SA Node [Pacemakers] –> Atria Contract –> AV Node –> Purkinje Fibres–> Ventricles Contract
Sinoatrial (SA) Node
- A bundle of specialized muscle located in the wall of the right atrium
- Stimulates muscle cells to contract & relax rhythmically
- Generates an electrical signal that spreads over the two arteries and makes them contract simultaneously
It STARTS the impulses stimulating the heartbeat
Atrioventricular (AV) Node
- As the atria contracts the signal reaches the AV node
- AV nodes transmit the electrical signal through a bundle of specialized fibre called the bundle of His
- Those fibres relay the signal through two bundle branches that dive into fast, conducting Purkinje fibres, which start almost simultaneous contraction of all cells of the right & left ventricles
Purkinje Fibre
A nerve fibre that branches and carries electrical impulses throughout the ventricles
Heart Sounds
- The sound the heart makes can be described as a “lubb-dubb” sound
- This sound is made by the closing of the different heart valves
Lubb Sound
- When the atria relax they fill with blood
- The atria the contract, which increases fluid pressure and forces the AV valves open
- This causes blood to flow from the atria to the ventricles
- Next, the ventricles contract and this pressure forces the AV valves shut which produces the lubb sounds and pushes blood through the semilunar valves and into the arteries
Dubb Sounds
- Next, the ventricles relax and their volume increases
- This causes the pressure in the ventricles to decrease and blood is drawn to this area of lower pressure
- Blood is prevented from re-entering the ventricles by the semilunar valves
- The closing of the semilunar valves creates the dubb sound
Cardiac Output
Amount of blood PUMPED by the heart each minute
Heart Rate
Number of heartbeat per minute
Stroke Volume
Amount of blood forced out of the heart with each heartbeat
Formula For Cardiac Output
Cardiac Output = Heart Rate X Stroke Volume