The need for a circulatory system Flashcards
Roles of the circulatory system
-Delivery of nutrients and oxygen to every cell
-Removal of waste products from cellular processes
-Pathway of immune system(white blood cells)
-Control of body temperature
Types of circulatory systems
- Open circulatory systems
- Closed circulatory systems
Open circulatory system
-Found in invertebrates such as insects
-Transport system in which blood doesn’t stay contained in blood vessels
-A single vessel, the aorta, carrie’s blood into the organisms body cavity and makes direct contact with organs and tissues
-Movements in the organism move blood around
Closed circulatory system
-Fluid(blood) is contained in blood vessles
-Blood is transported in one direction throughout the body in blood vessles
-Example: humans, birds
Types of circulation
- Complete, single circulation
- Incomplete, double circulation
- Complete, double circulation
Complete, single circulation
-Two chambered heart
-Complete because oxygenated and deoxygenated blood do not mix
-Single circulation because blood moves through heart only 1 time
-example: fish
Incomplete, double circulation
-Three chambered heart
-Double because the blood is carried through the heart twice during each cycle
-Incomplete because oxygenated and deoxygenated blood mix in the ventricle of the heart
-This mixing decreases the efficiency of the circulatory system
-example: frog
Complete, double circulation
-Four chambered heart
-Oxygenated and deoxygenated blood stays separated in blood vessles and heart
-Example: mammals
Mammals
-Mammals have a 2 circuit circulatory system
-Pulmonary circuit: circulates blood to the lungs for gas exchange
-Systemic circuit: circulates blood around the body to deliver oxygen, nutrients, and other substances to the body cells and to pick up CO2
Blood
-Humans contain 4-5L of blood
-Two components of blood are
*Plasma
*Cellular component
Functions of blood
1.Transportation
*Nutrients and O2 diffuse from the blood into the tissues and then into the cells
*CO2 and metabolic wastes move in the reverse direction
2. Protection from disease
3. Temperature regulation
*The circulatory system regulates temperature by changing the volume of blood flowing near the skin to potentially release extra heat
Blood vessels can either…
-Expand to release heat(vasodilation)
OR
-Contract to conserve heat(vasoconstriction)
Plasma
-90% is water
-Watery liquid with dissolved substances including glucose, water, oxygen, vitamins, minerals, and waste
-Protiens
*Albumins: determine amount of water that leaves and enters the cell by diffusion
*Globulins: Transport lipids, cholesterol and fat soluble vitamins
*Fibrinogen: Blood clotting
The cellular component of blood
-red blood cells
-white blood cells
-platelets
Red blood cells
-Called “erythrocytes”
-Contain oxygen carrying protein, hemoglobin
-Biconcave disk shape increases surface area for gas exchange
-Formed in bone marrow and as they mature. their nucleas breaks down and disappears(increases space for hemoglobin)
-Main job is to carry O2
-life span is about 120 days
-Once they die, they are removed in liver and spleen
-When they drop numbers, the brain tells the kidneys to make erythropoietin(EPO) which stimulates the production of RBC’s from the bone marrow
