Circulatory System
Chapter 12
Circulatory System - Transport blood + nutrients + waste around the body
Circulatory System Functions
= Transportation
- Gases (from resp. system)
- Nutrient molecules
- Waste materials (digestive system)
= Regulate internal temp. + transport vital chemical substances
= Protect against blood loss from injury + against disease-causing microbes/toxic
substances
Circulatory System Major Components
Heart + Blood vessels = Cardiovascular system
= Heart
- Muscular organ
- Pumps blood through body
- Generates blood flow
= Blood vessels
- System of hollow tubes for blood to move
= Blood
- Fluid that transports materials (nutrients, O2, CO2 etc.) throughout the body
Types of Circulatory System
Open Circulatory System
= Many invertebrates
= Blood flows freely within the body cavity
- Makes direct contact with organs + tissues
- No distinction between blood and interstitial fluid
- Blood + fluids that surround the cells (interstitial fluid) = Hemolymph
= Hemolymph is pumped via a single vessel that runs from head to abdomen
, - In abdomen, the vessel divides into chambers (insect’s heart)
- Tiny holes in heart wall (ostia) allow hemolymph to enter from the body
cavity
- Hemolymph pushed between chambers via muscle contractions
- Nutrients + wastes are exchanged between hemolymph
and cells in heart chambers
- Then hemolymph passes back into the transporting
vessel to leave the insect’s body
Closed Circulatory System
= Blood is contained within vessels
- Separate from the interstitial fluid + body tissues
= Blood follows a continuous fixed path of circulation
Human Heart
= Heart walls are made of cardiac muscle
- Allow the heart to contract + relax rhythmically without being tired
= Heart makes sure the blood flows in 1 direction + oxygenated blood is separate
from deoxygenated blood
Heart Structure
= 4 chambers (top + bottom chambers, right and left sides)
= 2 top chambers are the atria
- Filled with blood returning from the body/lungs
= 2 bottom chambers are the ventricles
- Receive blood from the atria + pump it out to the body/lungs
= Atria + Ventricles are separated by a septum (thick muscular wall)
Heart Four Chambers
Right side
= Receives deoxygenated blood (from the body) + pumps it to the lungs
= Vena cava (2 large vessels) open into the right atrium
- Superior vena cava collects deoxygenated blood that come from the head,
chest + arms
, - Inferior vena cava collects deoxygenated blood from the rest of the body
= Deoxygenated blood flow from the right atrium to the right ventricle (up then down)
- It leaves via pulmonary trunk
- Enters the left + right pulmonary arteries
- Blood then goes to the left + right lungs for gas exchange
- Pulmonary arteries are the only arteries with deoxygenated
blood
Left side
= Receives oxygenated blood from both lungs + pumps it out to the body
- Blood enters left atrium via pulmonary veins
- They’re the only veins that have oxygenated blood
= Left atrium pumps blood into the left ventricle (up then down)
- Blood leaves via aorta (largest vessel in the body)
- Aorta connects with other arteries
Heart Valves
= 4 valves to ensure the blood flows in correct direction
= Atria + ventricles separated by two valves ( atrioventricular valves)
- Tricuspid valve is on right side
-Made of 3 flaps
- Bicuspid valve/Mitral valve is on left side
- 2 flaps
= Other two valves called semilunar valves (between the ventricle and the large
arteries)
- Carries blood away from heart
- Pulmonary semilunar valve (right side)
- Aortic semilunar valve (left side)
Chapter 12
Circulatory System - Transport blood + nutrients + waste around the body
Circulatory System Functions
= Transportation
- Gases (from resp. system)
- Nutrient molecules
- Waste materials (digestive system)
= Regulate internal temp. + transport vital chemical substances
= Protect against blood loss from injury + against disease-causing microbes/toxic
substances
Circulatory System Major Components
Heart + Blood vessels = Cardiovascular system
= Heart
- Muscular organ
- Pumps blood through body
- Generates blood flow
= Blood vessels
- System of hollow tubes for blood to move
= Blood
- Fluid that transports materials (nutrients, O2, CO2 etc.) throughout the body
Types of Circulatory System
Open Circulatory System
= Many invertebrates
= Blood flows freely within the body cavity
- Makes direct contact with organs + tissues
- No distinction between blood and interstitial fluid
- Blood + fluids that surround the cells (interstitial fluid) = Hemolymph
= Hemolymph is pumped via a single vessel that runs from head to abdomen
, - In abdomen, the vessel divides into chambers (insect’s heart)
- Tiny holes in heart wall (ostia) allow hemolymph to enter from the body
cavity
- Hemolymph pushed between chambers via muscle contractions
- Nutrients + wastes are exchanged between hemolymph
and cells in heart chambers
- Then hemolymph passes back into the transporting
vessel to leave the insect’s body
Closed Circulatory System
= Blood is contained within vessels
- Separate from the interstitial fluid + body tissues
= Blood follows a continuous fixed path of circulation
Human Heart
= Heart walls are made of cardiac muscle
- Allow the heart to contract + relax rhythmically without being tired
= Heart makes sure the blood flows in 1 direction + oxygenated blood is separate
from deoxygenated blood
Heart Structure
= 4 chambers (top + bottom chambers, right and left sides)
= 2 top chambers are the atria
- Filled with blood returning from the body/lungs
= 2 bottom chambers are the ventricles
- Receive blood from the atria + pump it out to the body/lungs
= Atria + Ventricles are separated by a septum (thick muscular wall)
Heart Four Chambers
Right side
= Receives deoxygenated blood (from the body) + pumps it to the lungs
= Vena cava (2 large vessels) open into the right atrium
- Superior vena cava collects deoxygenated blood that come from the head,
chest + arms
, - Inferior vena cava collects deoxygenated blood from the rest of the body
= Deoxygenated blood flow from the right atrium to the right ventricle (up then down)
- It leaves via pulmonary trunk
- Enters the left + right pulmonary arteries
- Blood then goes to the left + right lungs for gas exchange
- Pulmonary arteries are the only arteries with deoxygenated
blood
Left side
= Receives oxygenated blood from both lungs + pumps it out to the body
- Blood enters left atrium via pulmonary veins
- They’re the only veins that have oxygenated blood
= Left atrium pumps blood into the left ventricle (up then down)
- Blood leaves via aorta (largest vessel in the body)
- Aorta connects with other arteries
Heart Valves
= 4 valves to ensure the blood flows in correct direction
= Atria + ventricles separated by two valves ( atrioventricular valves)
- Tricuspid valve is on right side
-Made of 3 flaps
- Bicuspid valve/Mitral valve is on left side
- 2 flaps
= Other two valves called semilunar valves (between the ventricle and the large
arteries)
- Carries blood away from heart
- Pulmonary semilunar valve (right side)
- Aortic semilunar valve (left side)
