Cardiovascular System Flashcards
What is the Circulatory System?
A NETWORK of ORGANS and VESSELS (transportation!) responsible for the FLOW of blood, nutrients, gases, and hormones to and from the cells in the body. Aka the Cardiovascular System.
What are the 4 main functions of the Circulatory System?
To TRANSPORT OXYGEN and carbon dioxide around the body, to DISTRIBUTE NUTRIENTS and transport waste, to MAINTAIN BODY TEMPERATURE, and to CIRCULATE HORMONES.
What are the 2 types of Circulatory Systems?
OPEN Circulatory Systems and CLOSED Circulatory Systems
What is the Open Circulatory System?
For SIMPLE (less complex) organisms, such as smaller organisms like insects. Blood bathes the internal organs DIRECTLY (blood contained in vessels PART of the time).
What is the Closed Circulatory System?
Found in large, COMPLEX organisms, like humans. Materials are exchanged BETWEEN the blood and cells (blood ALWAYS contained in vessels).
What are the main components of the Circulatory System?
The HEART, BLOOD, and BLOOD VESSELS.
What are the 3 types of Blood Vessels?
ARTERIES, VEINS, and CAPILLARIES.
What are Arteries?
THICK muscle and ELASTIC fibres (small in diameter) that carry oxygenated blood AWAY from the heart (except for the pulmonary artery). They can withstand high pressures from the heart.
What are Arterioles?
What Arteries BRANCH into. Ca contract and relax.
What is Vasoconstriction?
The REDUCTION (contraction) in diameter of blood vessels, which DECREASES blood flow.
What is Vasodilation?
Occurs when the vessel is RELAXED, there is an INCREASE in diameter of the blood vessel that INCREASES the blood flow.
What are Veins?
THIN muscle and ELASTIC fibres that are large in diameter (elastic but NOT flexible). All veins carry deoxygenated blood BACK TO the heart (except the pulmonary vein).
What are Venules?
SMALLER vessels carrying blood to the heart.
What strategies help with the flow of venous blood against gravity?
VALVES and SKELETAL MUSCLES.
What do Valves do?
They prevent BLOOD from flowing BACKWARDS against the flow in the VEINS.
What do Skeletal Muscles do?
They PUMP blood TOWARDS the heart.
What are Capillaries?
Smallest type of blood vessel with THIN walls (one cell thick). They CONNECT arterioles to venules and this is where gas exchange occurs.
Where does Diffusion take place?
In the CAPILLARIES.
What is Diffusion?
When particles of HIGH concentration MOVE to an area of LOW concentration.
What is the order of Blood Vessels?
Arteries, Arterioles, Capillaries, Venules, and Veins
What cause bruises?
When capillaries (fragile!) are RUPTURED through impact and the blood they contain is RELEASES into the space between tissues. This causes discolouration and swelling.
What is blood made up of?
Plasma (55%), Red Blood Cells (RBC or erythrocytes), White Blood Cells (WBC or leukocytes), Platelets.
What is Plasma made up of?
90% H2O, 10% proteins, dissolved nutrients and wastes, dissolved gases, hormones.
What are Red Blood Cells?
LOSE NUCLEI that are disc-shaped. They are produced in the bone marrow and live for 100-120 days. Contains HEMOGLOBIN.
What is Hemoglobin?
A protein in RBC (250 million molecules each) that BINDS to CO2 after RELEASING O2 at tissues.
What are White Blood Cells?
Round cells produced in the bone marrow that GUARD AGAINST infection, FIGHT parasites, and ATTACK bacteria (increase in number when fighting). Live from 12 hours to 200 days.
