Chp 22 23 gas exchange Flashcards
Why do our cells need O2?
to produce ATP
Why do our cells produce CO2?
waste product of cellular respiration.
what is the role of respiratory system?
designed for gas exchange between organism and enviornment
what is the cardiovascular system role?
transport gases within blood
what are three phases of gas exchange in humans?
- Breathing (ventilation)
- Transport (of oxygen and CO2)
- Exchange of gases within body cell
What are the breathing control centers?
Pons and medula oblongata.
What is the pulmonary circuit?
Carries blood from the heart to the lungs (for reoxygenation) and back to heart
what is the systemic circuit?
carries blood from heat to body tissues
what is diastole?
heart is relaxed, blood flows into all chambers, AV valves open
What is Systole?
2 stages of contraction:
- Atria briefly contracts to fill the ventricles with blood
- Ventricles contract and pump blood out
what is cardiac output?
Vol, of blood per minute pumped by the ventricles
what is SA node?
Sinoatrial node is the pacemaker- generates electrical signals in atria
what is the cardiac cycle controlled?
Signals from SA node spread through atria
Signals are delayed at AV node
Specialized muscle fibers pass signals to the heart apex
Signals spread throughout the ventricles
Which artery is blocked during a heart attack?
coronary artery feeding the heart
what are the 3 layers that make up Arteries and Veins?
- Endothelium
- Smooth Muscle
- Connective tissue
how many capillaries are open at one time?
5-10%
What is capillary blood flow controlled by?
- Contraction and relaxtion of smooth muscle in arterioles
- Open/close of precapillary sphincters
what is another word for White blood cells?
Leukocytes
What percentage of plasma is water?
90
What substances are contained in plasma?
Water, ions, plasma proteins, substances tranported by blood
What are 2 clotting factors?
Platelets (circulating cell fragments which form a plug)
fibrinogen (blood vessel injury leads to a chain of reactions)
What is the process of blood clotting?
1 Platelets adhere
- platelet plug forms
- fibrin clot forms
What is bloods pathway through the heart?
- blood enters riht atrium from superior and inferior vena cavae, and the coronary sinus
- From right atrium, it goes through the tricuspid valve to the right ventricle
- from right ventricle, it goes through the pulmonary semilunar valves to pulmonary trunk
- from trunk, it moves to right and left pulmonary arteries into the lungs
- lungs -> oxygenated blood is returned to heart through pulmonary veins
- pulmonary veins -> blood flows into left atrium
- left atrium -> blood flows through bicuspid valve itnto L ventricle
- L vent -> aortic semilunar valves nto ascending aortal.
- blood is distributed to rest of body from aorta.
