Transport System Flashcards
Be able to identify all of the parts of the heart in a diagram.
Top left tube is the superior vena cava, below that is the right atrium, the tube below is the inferior vena cava, to the right of that is the right ventricle, to the right and slightly above is the left ventricle, above that is the left atrium. To the right is the pulmonary vein. The tube above the left atrium is the pulmonary artery. In the direct top middle is the aorta.
Know the pathway of blood to, through, and from the heart.
- The vena cava deliver deoxygenated blood from the body to the right atrium
- The right atrium pumps deoxygenated blood through the right AV valve (tricuspid valve) into the right ventricle
3.The right ventricle pumps deoxygenated blood out of the heart through the right semilunar valve (pulmonary valve) into the pulmonary arteries, which carry it to the lungs (to exchange CO2 for O2)
4.Oxygenated blood from the lungs returns to the heart through the pulmonary veins and is delivered to the left atrium
5.The left atrium pumps oxygenated blood through the left AV valve (bicuspid/ mitral valve) into the left ventricle
6.The left ventricle pumps oxygenated blood out of the heart through the left semilunar valve (aortic valve) into the aorta, which carries it to the body
Be able to explain the roles of valves in the heart
-valves in veins and the heart ensure circulation of blood by preventing backflow
1. As atria fill with blood, pressure in atria > pressure in ventricles, AV valves open and blood flows from atria into ventricles
2. As ventricles contract , pressure in ventricles > pressure in atria, AV valves close = “lub”
3. As ventricles contract, pressure in ventricles > pressure in arteries, semilunar
valves open
4. As the arteries fill, arterial pressure > pressure in ventricles, semilunar valves
close = “dub”
Explain the events in one cardiac cycle
Systole (contraction)
* As atria contract, atrial pressure exceeds ventricular
pressure (AV valves open → blood flows to ventricles)
* As ventricles contract, ventricular pressure exceeds
atrial pressure (AV valves close → 1st heart sound)
* Pressure builds until the
ventricular pressure exceeds the arterial pressure
* Semilunar valves open and blood flows into arteries
Diastole (relaxation)
* As blood flows into arteries, ventricular pressure drops
* Backflow closes semilunar valves → 2nd heart sound
* When ventricular pressure drops below atrial pressure,
the AV valves will open and cardiac cycle is repeated
Be able to explain the control of the heartbeat/ heart rate
-heart rate is initiated by a group of specialized muscle cells
-SA node acts as a pacemaker and sends out electrical signals that stimulate contraction
-SA node starts the heartbeat by generating an impulse which causes atria to contract
-AV node delays for 1 second then sends signals down the septum of the ventricles through conducting fibers, impulse spreads to cardiac muscle, and causes ventricles to contract, so that blood is pushed from ventricles to arteries
-Myogenic control
-epinephrine controls fight or flight
Be able to explain the use of a defibrillator and artificial pacemaker.
Defibrillator:
-paddles or electrodes placed on a person’s chest, that delivers an electrical shock that depolarizes the heart muscle so SA node can re-establish a normal rhythm
-stops fibrillation
Artificial Pacemaker:
-medical device that delivers electrical stimuli to heart to regulate heartbeat.
- Connects to heart by wires and detects if heart’s natural rhythm is
incorrect.
-If so, it sends electrical impulses to heart to coordinate contraction
Be able to explain how blood vessel structure is related to its function for: arteries, veins, and capillaries
-arteries and veins have three layers
-blood pressure is high in arteries and low in veins
-arteries get blood from heart ventricles and carry that blood away from the heart
-the lumen of the artery is small to help maintain a high blood pressure
-arteries have thick walls with elastic fiber
-elastic fibers recoil when the heart contracts
-veins receive blood from capillaries
-veins have a large lumen so there is less resistance to blood flow
Know the components of blood and what is transported by the blood.
Blood contains three main elements:
* Red blood cells (transport oxygen)
* White blood cells (fight infections)
* Platelets (responsible for clotting)
The blood fluid (plasma) transports:
* Nutrients (e.g. glucose)
* Antibodies
* Carbon dioxide
* Hormones
* Oxygen
* Urea
* Heat
Be able to explain how materials are exchanged between the capillaries and tissues
-molecules are moved through diffusion
-nutrients are moved into tissues
-there is a gas exchange where oxygen and carbon dioxide is exchanged between tissue and blood
Be able to outline the role of valves in veins.
-unidirectional flow
-continue carrying blood towards the heart
Know what atherosclerosis is and be able to explain the process of how it can cause occlusions and/ or clot formation in the coronary arteries.
-Atherosclerosis: build-up of plaque deposits (fats, cholesterol, cell debris etc.) in arteries
-Plaque deposits cause increased blood pressure (narrower lumen) in arteries, which causes chronic inflammation and damages endothelial wall
Be able to explain the consequences of occlusions of the coronary arteries and the risk factors for developing CHD.
Coronary thrombosis is caused by clots within the coronary arteries
* Vessels are damaged by cholesterol deposition (atherosclerosis)
* The deposits reduce vessel diameter and increase blood pressure
* The stress damages arterial walls (and is repaired with fibrous tissue)
