Lecture 6: Cardiovascular 1: Overview and Anatomy Flashcards
How many chambers and valves does the heart have?
The heart has 4 chambers (2 atria and 2 ventricles) and 4 valves: 2 AV valves (tricuspid; right and bicuspid; left) and 2 Semilunar valves (aortic and pulmonary)
What are the 2 types of circulatory systems? Why is the heart separated?
- Pulmonary circulatory system (Arteries –> veins.–> lungs
- Systemic circulatory system
(arteries –> veins –> rest of body)
The heart is separated into 2 parts to prevent the mixing of oxygenated and deoxygenated blood
What are the major functions of the CVS?
-Transport nutrients (from intestine to tissues or from.to liver and fat)
-Transport waste (that is produced by body from production to excretion sites
-Transport heat (from inside to the skin)
-Transport hormones (endocrine glands to target cells)
-Carrying immune cells (neutrophils get dropped at area of inflammation)
-Stabilize internal environment (buffer pH, ions etc)
TRUE OR FALSE: The layer around the heart is called the pericardium and it consists of 2 layers.
TRUE: 2 layers of connective tissue with cavity.
-Visceral layer (attached to the heart)
-Reinforced parietal layer
This prevents over-sizing of the heart. The cavity (like balloon/slippery jacket) is filled with fluid which allows some movement
The heart wall is made of what type of tissue? What is the endocardium?
The heart is same of muscle tissue called myocardium. And the different half of the heart are separated by a muscular septum
The endocardium= epithelium covering the inner surface so that the heart doesn’t steal the nutrients in the blood. (coronary arteries brings 02 to heart so separate system)
What tissue are the heart valves made from and what prevents the back flow?
They are made of fibrous connective tissue attached to a fibrous ring.
In the AV valves (bi and tricuspid), the free end of the AV valve is attached to papillary muscle in ventricle (presents inversion, limits movement) and chord tendineae act like ropes and prevent the valves from swinging back open.
What does the opening and closing of valves depend on?
This is a passive mechanism that is dependent on blood pressure. ALL about HIGH->LOW
-Ventricles relax = lower pressure = AV valves open
-Ventricles fill = higher pressure = AV valves close
-Ventricles contract = pressure higher than arterial pressure –> causing aortic and pulmonary valves to open
-Ventricles emptied = pressure back down, all valves are closed
What are the 2 ‘great vessels’?
Generally: Arteries (convey blood from the heart to tissues and organs) and viens (convey blood from tissues and organs to the heart)
Specifically Arteries:
Pulmonary arteries (leave right ventricle to bring deoxygenated blood to the lungs)
Aorta: Leaves the left ventricle to bring oxygenated blood to the rest of the body
Specifically veins:
Vena cava: (2;cranial or superior, brings deoxygenated blood to the right atrium)
Pulmonary vein: Brings oxygenated blood to the left atrium
What is the flow of blood vessels starting form leaving the heart?
-Arteries: branch off aorta and pulmonary arteries. Receive tremendous pressure from ventricle contractions so need to be elastic.
- Small arteries (arteriole): deliver blood locally to arterioles and capillaries in tissues. Control the pressure via tone of vessels smooth muscle
-Capillaries:Site of gas and nutrient exchange etc
-Venules: collect blood from capillaries
-Veins: Receive blood from venues and return it to the heart. Change in tone will alter ‘venous return’ (problem if there isn’t enough pressure to return blood back. to the heart)
*note lose elastic tissue when become smaller but gain smooth muscle to control flow and pressure when coming back to the body. Capillarities only have endothelium tissue no smooth muscle or elastic
What is the difference between the pulmonary and systemic systems?
*Both have arteries and veins
-Pulmonary=heart/lungs loop to oxygenated blood, relatively low pressure, low resistance, highly distensible
-Systemic=Distribution of oxygenated blood and nutrient throughout the body. High pressure and high resistance
Left ventricle is 5-7fold greater then right venture and wall much thicker
What is cardiac output? And areas receive more blood and why?
Cardiac output= blood pumped by each half of the heart per min
-Right side is 100% to the lungs
-Left is to the rest of the body but not in equal portions(ex digestive tract is less weight then other organs but receives 1/2 of the blood bc nutrient intake in very important here or kidneys are tiny but also take 1/4 of blood supply)
what is the cardiac cycle?
Repeating pattern of contraction and relaxation of the heart. Has to be synchronized.
-Systole=phase of contraction (ejection)
-diastole=phase of relaxation (filling)
A 2 step pump; both atria contact simultaneously to push blood into ventricles and right/left ventricles contract 0.1-0.2 seconds later
What are the individual events of the cardiac cycle?
- Diastole (blood returning from venous)
- Atrial contraction (pack blood in ventricles)
- Isovolumic contraction (All valves closed bc pressure not sufficient to open AV valve)
- Ejection phase, systole (now semi-lunar valves open and allow blood to flow out)
- Isovolumic relaxation (all valves close)
