Cardiovascular Systems Flashcards
Primary roles of the cardiovascular system
- to transport ___oxygen _____ from the lungs to the tissues (muscles)
- to transport _carbon dioxide ___________ from the tissues to the lungs ( comes from muscles being used)
- to transport nutrients from the digestive system to other areas in the body ( macronutrients )
- to transport waste products from sites of production to sites of excretion.
The structure of the heart
Heart is comprised of cardiac muscle (and vessels of smooth muscle) that serves to pump blood through the human body.
•consists of four chambers:
Atria (right atrium and left atrium) receive blood from peripheral organs and pump blood into the ventricles
Ventricles (left and right) pump blood through the body,
Right ventricle pumps blood to the lungs
Left ventricle pumps blood through the entire body (are larger and with stronger muscle walls than the RV)
Ventricles
Bottom chamber
Atria
Chambers on the top
The right atrium receives deoxygenated blood from the ________ and the ________
Superior
Inferior vena cava
The blood moves from the _________ to the ________and pumps it to the lungs
Right atrium
Right ventricle
Blood travels to the lungs through the ….
Pulmonary arteries
Blood that enters the left atrium via
Pulmonary veins
(Oxygenated blood)
The left atrium receives the ______ blood from the lungs and pumps it to the ________
Oxygenated
Left ventricle
Once blood is oxygen rich it is transported to the body via the
Aorta
The largest artery
Heart structures: chambers
Chambers (actual flow)
Blood flows throughout chambers in both right and left sides simultaneously.
Diastole
Ventricles relaxing and filling with blood
Systole
Ventricles contracting, push blood through
-pulse of blood is systole HR
Blood flow
Cardiac cycle
Cardiac cycle
See diagram
Rules of arteries
Arteries carry oxygenated blood EXCEPT the pulmonary artery
-all arteries carry blood away from the heart
Rules of veins
Veins carry deoxygenated blood EXCEPT the pulmonary vein
- all veins carry blood back to the heart (i.e venous returns)
Sound of heart is
Valve opening and closing
-heart murmur is problems with the valve
Heart tissue blood supply ( where does the heart get its blood)
Coronary arteries and coronary veins
- heart needs its own blood supply
Heart attack is when blood supply to the heart is cut off
Circulatory system neural drive
Neural control over heart rate is also through the Involuntary (Autonomic) Nervous System which is responsive to:
• emotional changes (stress)
• CO2 and O2 blood levels (based on metabolism)
• proprioceptive changes (response to stress)
• etc.
The heart - hemodynamics
Average bpm
60-80 bpm
Trained individuals have a lower heart rate, stroke volume is going up( amount of blood ejected per beat) heart doesn’t have to beat as often
World class long distance runner = 30 bpm
Tachycardia
Persistent resting rate > 100 bpm
Caffeine can effect this
Bradycardia
Persistent resting rate < 60 bpm
Health heart
Stroke volume
= ml/beat (systole)
Cardiac output
Volume ejected 1/min
= heart rate (bpm) x stroke volume (ml/beat)
At 80 bpm x 60ml/beat = 4.8L
Total volume of blood ejected in a minuet
Larger contraction or heart beating more often = more blood
Heart rate during exercise
Increase directly proportional to increases in exercise intensity (linear relation)
This is why you can predict maximal from the submaximal
Vessels: the peripheral circulatory system
Comprised of the arteries that carry blood away from the heart to the muscle and organs and veins return that blood to the heart
All of the vessels of the body are made up of smooth muscle cells that allow them to contract or relax (happens according to metabolic need) they can constrict or dilate
They regulate blood flow and alter the pattern of circulation throughout the body
Vessels that carry blood away from the heart are called _____
Arteries
Arteries branch into smaller and smaller vessels called ____
Arterioles
The arterioles branch into even smaller vessels called _____
Capillaries
Capillaries
Allow for the exchange of oxygen and nutrients form the blood to muscles and organs
-allow blood to pick up the waste products and carbon dioxide from metabolism
Veins ( blood flow and valves)
Blood flow towards the heart opens the valves
Blood flow away from heart closes the valves
In comparison to arteries, veins have valves that _____________________ to the heart and ____________ from the heart
Opens as blood returns
Close as blood flows away
Vasodilation
Increases blood flow
Vasoconstriction
Decrease blood flow
At rest: blood flow (where is it going)
50% of blood to liver and kidney
15% blood to muscle
Heavy endurance : 80% blood to muscle
Blood pressure (+ avgs) diastolic and systolic
Pressure exerted on the vessels using systole (contraction of muscles) and diastole (relation of muscles) pressure is highest at the heart
Systolic pressure avg. 120mmHg
Diastolic pressure avg. 80 mmHG
Blood : plasma
Approx. 55% of blood
Is comprised mostly of water
Blood: formed elements
Approx. 45%
Comprised mainly (99%) of red blood cells
Also white blood cells and platelets
Functions of red blood cells
One of the primary functions of red blood cells is to transport oxygen form the lungs to th tissues. They are able to do this because of a substance called hemoglobin
In 1 liter of blood, hemoglobin store 200 ml O2
Blood and exercise
Increase partial pressure of CO2 decrease partial pressure of O2 is “sensed” in the carotid bodies (carotid arteries)
Signal sent to respiratory center in medulla- which sends signal to heart to increase heart rate (need more oxygen, tells brain to change breathing)
Exercise and heart rate/blood
Exercise = increase heart rate via Proprioceptors signal to heart center in medial, which signals heart to increase rhythm
Muscular activity increase venous return (muscle pump) which increase ventricular preload( loading the left ventricle)
Ventricles thus contract more forcefully and expel more blood ( if we stretch the left ventricle, by preloading, the heart more forcefully contracts = more blood)
Sustained exercise creates a more efficient heart:
Somewhat increased size of cavities and thickness of walls = cardiac hypertrophy
-increased stroke volume
-allows heart to beat more slowly at rest (higher stroke volume)
Also: increase in red blood cells
Increased capillaries
Th Heart contracts in a constant rhythm that may speed up or slow down depending on ________________
The need for oxygen and blood in the body
The beating of the heart is governed by an automatic electrical impulse generated in the _____
Sinus node
The sinus node is a small bundle of nerve fibers that are found in the wall of the ___________
Right atrium
The sinus node generates an electrical charge called ____________
Action potential
The action potential causes muscles of the heart to contract. This action potential travels through the two _________ to a v node and is then distrusted to the two ventricles via the ________
Atria
Purkinje fibers
The atria contract before the _______, which allows for the blood to be quickly pumped into the ventricles from the atria
Ventricles
