Circulatory System Flashcards
(30 cards)
What is TRANSPORT?
The process by which substances move into or out of cells or are distributed within cells
Do simple organisms need a special system for transport? How do materials get around?
No - they just diffuse within and between cells
What does the circulatory system do?
It transports materials to and from all parts of the organism
What are the three parts of the circulatory system?
- A fluid in which materials are transported - blood
- A network of tubes or body spaces through which the fluid flows - veins and arteries
- A pump - the heart
What does blood do?
Picks up and delivers needed materials, like oxygen, nutrients, and water to your cells.
Picks up waste products from the cells, like urea and carbon dioxide
What do veins do? What kind of blood do they carry?
Carry blood to the heart
Contain one-way valves that keep the blood flowing through the heart
Many are located near skeletal muscles, so when the muscle contracts, blood is forced through
What do arteries do? What kind of blood do they carry?
Carry blood away from the heart
A FOR AWAY
All of them carry oxygen rich blood except for pulmonary artery
Have thick walls that withstand the powerful pressure produced when the heart contracts and pushes blood into the arteries
What do capillaries do?
Connect veins and arteries
Smallest blood vessel
Walls are only 1 cell thick, so blood must pass through single file and nutrients and waste diffuse in and out easily
Where is the heart? What does it do?
It’s a muscle that pumps blood throughout the body
It’s located near the center of the chest and is a hollow organ around the size of a clenched fist
What is the pericardium?
A protective sac of tissue that encloses the heart
What is the myocardium?
Thick layer of muscle in the heart that provides powerful contractions to pump blood throughout the circulatory system
How many times per minute does the heart contract?
72, pumping about 70mL of blood with each contraction
What is the septum of the heart?
A wall that divides the heart
What is the upper side of the heart called? What does it do?
Atrium; it receives the blood
What is the lower side of the heart called? What does it do? How does its muscles compare to the upper side of the heart?
Ventricle - pumps blood out of the heart
The walls of the ventricle are thicker and more powerful than those of the atria
What do atrioventricular (A-V) valves do?
Allow blood to flow from the atria to the ventricles
Where is the tricuspid valve? How many flaps does it have?
Located on the right of the heart, contains three flaps
Where is the bicuspid valve? How many flaps does it have?
Located on the left and has two flaps
Where are the semilunar valves? What do they do?
Located between the ventricles and the arteries that lead away from them.
This prevents blood from flowing back into the ventricles
What happens in the right side of the heart?
PULMONARY CIRCULATION
Blood from all over the body comes into the right side and is pumped out towards the lungs. There, it can drop off carbon dioxide and pickup oxygen
What happens in the left side of the heart?
SYSTEMIC CIRCULATION
After oxygen is picked up from the lungs, the oxygenated blood flows into the left side and is pumped to the rest of the body
What is the AORTA? Where is it?
Largest artery
Leads from the left ventricle to the rest of the body
Where does the first sound (“lub”) of the heartbeat come from?
The bicuspid and tricuspid valves closing when ventricles squeeze
Where does the second sound (“dub”) of the heartbeat come from?
When the semilunar valves close, when your ventricles stop squeezing
