Circulatory System Flashcards
What surrounds the heart?
a bouble walled sac; pericardium
What are the four chambers of the heart?
2 atria (superior to two ventricles) 2 ventricles
What splits the heart in two?
septum
What are the atria involved in?
receiving blood from the body/lungs
What do the valves allow?
the blood to flow in only one direction
What are the four valves?
- tricuspid
- bicuspid (mitral)
- pulmonary
- aotric
What two systems are heart contraction regulated by?
the autonomic nervous system and te nodal system
What two main phases does the nodal system cause the heart to contract in?
1) atria contract (filling ventricles with blood)
2) ventricles contract (pumping blood to body)
What is the SA node or “pacemaker” of the heart?
A group of cells in the right atrium which controls the contraction of the atrium and sends a signal to the AV node with causes the ventricles to contract when the atria are beginning to relax.
Trace the path of blood through the heart.
1) Blood enters the heart through the superior and inferior venae cavae into the right atrium
2) Blood is pumped into the right ventricle
3) Blood is pumped into the pulmonary truck (which splits into the pulmonary arteries) to travel to the lungs for oxygenation (pulmonary circuit)
4) Blood returns to the heart through the pulmonary veins into the left atrium
5) Blood is pumped into the left ventricle
6) Blood is pumped into the aorta to be pumped to the body vells (systemic circuit)
What is the Cardiac or Coronary Circuit?
This is the travel of blood within the heart.
What is the Pulmonary Circuit?
The path of blood from the heart to the lungs.
What is the Systemic Circuit?
The path of blood from the heart ot the rest of the body
What is blood pressure?
the force the blood exerts agains tthe walls of our blood vessels (created by the pumping of our heart).
What does the cardia cycle refer to?
the events that occur in one complete heart beat
What is average heart rate?
75 beats/min
What is systole? (4 things)
> atria are relaxed (chambersa re filling with blood again)
tricuspid and mitral valves are closed
contraction of the ventricles
pressure on arteries is high
What is diastole? (4 things)
> relaxation of the ventricles
aortic and pulmonary valves are closed
contraction of the atria
pressure on arteries is low
List Systolic/Diastolic pressure levels.
Systolic/Diastolic
Normal: 120-129/80-84
High-normal: 130-139/85-89
High blood pressure (measure in a doctors office): 140/90
High blood pressure (measured at home with home monitoring device): 135/85
Do arteries carry blood away or towards the heart?
away (generally oxygenated blood)
What makes arteries elastic?
a thick layer of smooth muscle
Are arteries capable of withstanding high presure?
yes
Do arteries have a smaller or larger inner diameter than veins?
smaller
What do arteries divide into?
smaller arteries eventually leading into smaller branches called arterioles which then lead to the capillaries.
Are capillaires thin or thick walled? What does the wall consist of?
- thin walled
- consist of a single layer of endothelial cells
What are capillaries the location of?
gas, nutrient, and waste exchange
What do capillaries connect?
arteries and veins
What do capillaries intertwine among?
body cells
What are the largest blood vessels (diameter)?
veins
What do capillaries empty into?
venules, which in turn empty into veins
Are veins thick or thin walled?
thin
What do the valves in veins prevent?
back flow of blood
Trace the flow of blood through the heart and body.
1) right atrium
2) right ventricle
3) pulmonary artery
4) lungs
5) pulmonary veins
6) left atrium
7) left ventricle
8) aorta
9) body cells
10) vena cava
Trace the blood flow through the human circulatory system,
1) heart
2) arteries
3) arterioles
4) capillaries
5) venules
6) veins
Vessels which carry blood away from the heart?
arteries
Vessels which carry blood toward the heart?
veins
Tiny blood vessels with walls that are only one cell thick?
capillaries
Thick wall that divides the heart into two sides?
septum
Upper chambers of the heart that receive blood?
atrium
Lower chambers of the heart that pump blood out of the heart?
ventricles
Valve between right atrium and right ventricle?
tricuspid valve
Valve between left atrium and left ventricle?
biscuspid valve
Valves found between the ventricles and blood vessels?
semilunar valves
Membrance around the heart?
pericardum
The only artery in the body rich in carbon dioxide?
pulmonary artery
The only vein in the body rich in oxygen?
pulmonary vein
