Ch. 8 - Heart/Circulation Flashcards
What are the functions of the circulatory system? General.
Transport, Regulation, Prevention, Protection
What does the circulatory system transport?
- Gases
- Nutrients
- Waste Materials
- Hormones
What does the circulatory system regulate?
Internal temperatures
What does the circulatory system prevent?
Blood loss
What does the circulatory system protect?
- Disease causing microbes
- Toxic substances
The circulatory system can only function in what? What is the term for this?
A closed system, or closed circulation.
What is closed circulation?
Blood never leaves vessels.
The circulatory system is considered a what? What is the term for this?
A double system, or double circulatory system.
What is a double circulatory system? What are the two systems classified as?
In mammals, birds, and reptiles…
The blood is pumped twice before returning to its origin.
1. Pulmonary Circulatory System
2. Systemic Circulatory System
In fish and other lower animals, this happens only once.
What is a pulmonary circulatory system?
Relating to the lungs.
Between the heart and lungs
What is a systemic circulatory system?
Between the heart and body.
What are the three major components of the circulatory system?
- Heart
- Blood Vessels
- Blood
Which parts of the heart are pulmonary?
- L/R pulmonary arteries
- L/R pulmonary veins
- L pulmonary trunk
Which parts of the heart are systemic?
- Superior/Inferior Vena Cava
- Aorta (top and bottom)
Which parts of the heart are actually structures?
- Right Atrium
- Right Ventricle
- Left Atrium
- Left Ventricle
- (Apex)
Which stuctures of the heart are vessels?
- L/R pulmonary arteries
- L/R pulmonary veins
- L pulmonary trunk
- Superior/Inferior Vena Cava
- Aorta (top and bottom)
What are the heart’s 3 major functions? Which structures performs this?
- Pumping blood through the body (ventricles)
- Keeping oxygen rich blood seperate from oxygen poor blood (septum)
- Ensuring that blood flows only in one direction through the body (valves)
What is the pericardium?
Membrane surrounding the heart which prevents friction between heart and lungs.
What does the pericardium do?
Helps isolate infection.
What is the heart made of?
The walls of the heart are made up of specialized cardiac muscle tissue found nowhere else in the body.
How many chambers does the heart have?
All mammals and birds have 4 chambered hearts.
2 ventricles, 2 atria.
What do the atria do and where are they located?
The atria is the two top chambers and they recieve blood.
The right gets from the body.
The left gets from the lungs.
What do the ventricles do and where are they located?
The ventricles are the bottom to chambers and recieve blood from the atria.
They are much larger and muscular than atria.
The right pumps to the lungs.
The left pumps to the whole body.
What is the colouring of blood in corrolation to oxygen levels?
Dark red: deoxygenated
Light red: oxygenated
What does the septum do?
Is a thick muscular wall that seperates the left and right sides of the heart.
What is the path of blood through the body?
RIGHT SIDE: deoxygenated from body and pumps it into the lungs
1. From superior vena cava and inferior vena cava
2. Into the right atrium
3. Through the tricuspid valve
4. Into the right ventricle
5. Through the pulmonary semilunar valve
6. Out the pulmonary trunk, splitting into the pulmonary arteries, to lungs to remove waste and get O2
LEFT SIDE: getting oxygenated blood from the lungs
1. From pulmonary veins
2. Into the left atrium
3. Through the bicuspid valve
4. Into the left ventricle
5. Through the aortic semilunar valve
6. Out the aorta, to the body, where it becomes deoxygenated again
The right side of the heart recieves __ from the __ and pumps it back to the lungs.
Deoxygenated blood
Body
What do the vena cavae do? Where do they open into?
They open up into the right atrium.
The superior vena cava collects oxygen-poor blood from the head, chest, and arms (above the heart).
The inferior vena cava collects oxygen-poor blood from the rest of the body.
What do the pulmonary arteries do?
Gas exchange. The only arteries in the body that contain deoxygenated blood.
The left side of the heart recieves __ __ from the lungs and pumprs it out to the body.
Oxygen-rich blood
What does the aorta do? Where does it go to?
Blood’s pumped from the left atrium to the left ventricle and out to the body through the largest vessel in the body: the Aorta.
It is of oxygen-rich blood.
What do the pulmonary veins do?
Oxygen-rich blood flows from the lungs through the pulmonary veins into the left atrium. The only veins in the body that contain oxygenated blood.
Which side of the heart is stronger?
The left side is bigger and more muscular.
What are the four valves of the heart? What are they divided into?
- Atrioventicular valves
- Semilunar valves
What are the role of atrioventricular valves? For what?
One way valves that seperates the atria and the ventricles.
In heart.
What is the role of chordae tendinae?
(Tendon chords, which hold the bicuspid and tricuspid valve are held by)
Ensure blood is not pushed back into the atria during ventricular contraction.
Support valves.
What are the two atrioventricular valve called? Which side is each on and how many flaps does each have?
- Bicuspid (Mitral) Valve, left side, two flaps
- Tricuspid Valve, right side, three flaps
What are the role of semilunar valves?
At the entrance of the major arteries, pulmonary arteries/aorta, are smaller valves with no muscular attachment.
Out heart.
What are the two semilunar valves called? Which side is each on and how many flaps does each have? For what?
- Pulmonary semilunar valve in pulmonary artery (on the right side)
- Aortic semilunar valve in aorta (on the left side)
Has three flaps each to prevent backflow into ventricles.
Blood flows out of the heart through the aorta, into blood vessels. Where is the first blood vessel it flows to?
Arteries
More muscle = __ valves (in the context of arteries and veins)
Arteries don’t require valves because pressure from the heart is so strong that blood is only able to flow in one direction.
So, more muscle = less valves
What are arteries?
Carry blood away from the heart, usually oxygen-rich blood, with the exception of the pulmonary artery.
- Have thick walls with muscles that allow them to change in diameter
- Have the greatest pressure and are found deep within the body tissues
- Pulse can be felt in arteries because the blood travels in spurts as the heart contracts
- No valves
The largest artery: aorta.
What are arterioles?
Small arteries which lead into capillaries. They have muscles called precapillary sphincters, which can open or close and thus, regulate the flow of blood into the capillaries.
What are vasodilators? (from the blood vessels page)
Chemicals/nerves that cause artery smooth muscles to dilate (expand).
What are vasoconstrictors? (from the blood vessels page)
Chemicals/nerves that cause arteries/arterioles (smooth muscles) (and maybe precapillary sphincter) muscles to constrict (shrink).
What are capillaries?
The smallest blood vesssels. 10 bundled together would have the diameter of a human hair.
- The walls are only one cell thick, allowing materials to diffuse through to tissues.
- Are under low pressure and blood moves very slowly (often one cell at a time)
What are venules?
Capillaries merge and become larger vessels (like arterioles). No precapillary sphincters, but contain smooth muscle and valves.
What are veins? What muscle do they contain? How about their pressure? What else do they have that arteries don’t? How is blood moved?
Always carry blood to the heart (usually oxygen-poor blood, except the pulmonary vein).
- Contain smooth muscle.
- Have the least pressure.
- Have one-way valves that prevent blood from flowing backwards, especially important in the legs where blood must flow up against the flow of gravity.
- Blood is moved through veins by suction from the heart and the action of the muscles found around the veins.
What is the 6-step process of the beating heart? Which parts/processes?
- Sinoatrial node initation
- Stimulation through electric impulses
- Atria contraction
- Reaches Atrioventricular node, transmitting signal through specialized fibers called HIS
- Travels through HIS, divding into two branches, fast conducting purkinje fibers
- Impulse contracts ventricles
Where is the heart beat initiated? By what?
By specialized tissue called the sinoatrial node (aka the pace maker).
In the right atrium.
The sinoatrial node sends out impulses which __.
Stimulate the heart muscles in atria to contract.
The SA node’s electrical signal causes what to contract?
The two atria contracts simultaneously.
As the atria contracts and reaches the __ __, a new signal transmits through __.
The AV node, that transmits the signal through specialized fibers called the bundle of HIS.
What does the bundle of HIS divide into to transmit signals?
Purkinje fibers, that are fast conducting, and are two bundle branches
What happens as the signal reaches the purkinje fibers?
The ventricles contract (push against septum).
The heart beat is a cycle. What does this mean?
It’s lubb-dubb. It’s a two step process: the systole and diastole, and repeats.