Ch. 23 Circulation Flashcards
Circulatory System
The organ system that transports materials such as nutrients, O2, and hormones to body cells and transports CO2 and other wastes from body cells
Capillaries
A microscopic blood vessel that conveys blood between an artery and a vein or between an arteriole and venule; enables the exchange of nutrients and dissolved gases between the blood and interstitial fluid
- enables diffusion via intricate network
What is the function of the circulatory system?
Transport O2 and nutrients
Convey metabolic wastes to waste disposal organs (lungs, kidney)
What is the circulatory system’s 2 key roles in homeostasis?
1) Exchanged molecules cia interstitial fluid -> control makeup of environment cell lives in
2) Control makeup of blood by continuously moving it through organs
Blood
A type of connective tissue w/ a fluid matrix called plasma which blood cells are suspended
What are the 2 basic types of circulatory system?
- Open Circulatory System
2. Closed Circulatory System (Cardiovascular System)
Open Circulatory System
A circulatory system in which blood is pumped through open ended vessels and out among the body cells.
- blood and interstitial fluid are one and the same
- invertebrate (mollusks + arthropods)
Closed Circulatory System (Cardiovascular System)
A closed circulatory system w/ a heart and branching network of arteries, veins, and capillaries
- blood is confined to blood vessels
- interstitial fluid is separate
- vertebrates
What are the 3 kinds of blood vessels?
Arteries, veins, capillaries
Arteries
A vessel that carries blood away from the heart to other parts of the body
- O2 rich
- branch/subdivide for more surface area to reach more cells
- arteriole
Veins
A vessel that returns blood to the heart
- O2 depleted and wastes
- converge (get bigger) closer to heart
- veiniole
Capillaries
A vessel that conveys blood b/w arteries and veins
- sit of exchange b/w blood and cells (diffusion)
- small and thin (single file blood cells for maximized diffusion)
What are the 2 chambers of the heart?
Atrium and Ventricle
Atrium
A heart chamber that receives blood via veins
- thin walled
Ventricle
A heart chamber that pumps blood out of heart
- thick walled
Arterioles
A vessel that conveys blood b/w an artery and capillary bed
- smallest division of artery
Capillary beds
Network of capillaries that infiltrate every organ and tissue in the body
Venules
A vessel that conveys blood b/w a capillary bed and a vein
What are the 2 blood circuits of vertebrates?
- Pulmonary Circuit
2. Systemic Circuit
Pulmonary Circuit
Consists of all blood vessels that carry the blood from the heart to the lungs and back
- dumps off CO2, reloads O2
Systemic Circuit
All blood vessels that carry the blood from the heart to the body and back
- delivers oxygen and materials to all cells
What is the trip of blood in the cardiovascular system?
1) Right ventricle pumps blood to lungs
2) Pulmonary arteries
3) Blood in lungs unloads CO2, load O2 and flow to left atriumn via pulmonary veins
4) O2 flows into left atrium
5) O2 flows to left ventricle
6) Aorta
7) Upper body
8) Abdominal organs and lower body
9) Superior Vena Cava
10) Inferior Vena Cava
11) Venae cavae to right atrium to right ventricle
Pulmonary Arteries
A large blood vessel that conveys blood from the heart to a lung
- only artery with deoxygenated blood
Pulmonary Vein
A blood vessel that conveys blood from a lung to the heart
- oxygenated blood
Aorta
An artery that conveys blood directly from the heart to other arteries
- biggest
Superior Vena Cava
A large vein that returns O2 poor blood to the heart from the upper body and head
Inferior Vena Cava
A large vein that returns O2 poor blood to the heart from the lower, or posterior, part of the body
Cardiac Cycle
The alternating contractions and relaxations of the heart
1) Diastole
2) Systole
Diastole
The stage of the heart cycle in which the heart muscle is relaxed, allowing the chambers to fill w/ blood
- blood enters left and right atrium
- valves b/w atria and ventricles are open -> blood flow
- 0.4 sec
Systole
The contraction stage of the heart cycle, when the heart chambers actively pump blood
- 0.1 sec atria fill w/ blood
- 0.3 sec ventricle contract