Circulatory System
Blood Flow
Structure
Types
Makeup
Open System
Closed System
Interconnecting Vessels
Circulatory Fluid
Heart
Heart
Cardiac Cycle
Rhythm
Molecular movement
Types
Capillaries
Arteries
circulatory fluid
Veins
tubes that contain the circulatory fluid and acts like a transport system to the necessary organs and tissues
Hemolymph- interstitial fluid
Heart
Present in arthropods and some molluscs
pumps hemolymph to sinuses
relaxation pulls hemolymph back in
body movement helps circulate hemolymph
requires less energy
Circulatory fluid
Blood
present in annelids, molluscs and vertebrates
Blood is confined in vessels and separate from interstitial fluid
Heart
pumps blood to large vessels where chemical exchange occurs between blood and interstitial fluid and interstitial fluid and body cells
Closed - Blood
Open - hemolymph
pumps circulatory fluid through out the body so chemical exchange can happen wherever needed
Carries Circulatory fluid away from the heart to organs through the body
Carries circulatory fluid towards the heart
microscopic vessels that infiltrate tissues and allows diffusion of chemicals to occur between circulatory fluid and interstitial fluid
- Blood starts in the heart and is pumped to the lungs from the right ventricle
- Bloods flows through the pulmonary arteries towards the lungs through the pulmonary semilunar valve
- Gas exchange occurs in the lungs
- Pulmonary veins transport oxygen rich blood back to the left atrium
- blood passes through the atrioventricular valve into the left ventricle
- Blood is pumped from the left ventricle through the systemic semilunar valve into the aorta (aortic artery). Which is the main artery for transporting blood throughout the body
7/8. Chemical exchange occurs in capillary beds within the head, arms, abdominal organs and legs
9/10. Blood travels back to the heart via the interior (lower) and superior (upper) vena cova (vein) to the right atrium
- Blood is pumped from the right atrium to the right ventricle and cycle begins again
definition
one complete sequence of pumping and filling of the heart
Systole - contraction = pumps blood out
Steps
Atrial systole and ventricular diastole - atrial contraction forcing remaining blood into the ventricles emptying the atria
Ventricular systole and atrial diastole - ventricular contractions pumps blood into arteries through semilunar valves
- Atrial and ventricular diastole - relaxation of heart, blood is moved back into the heart from veins into the atria and then ventricles through the atrioventricular valves
controlled
Extrinsically - medulla oblongata sends signals to manipulate heart rate
Intrinsically - pacemaker cells in atrioventricular node
Process
electrical signals spread to walls of atria causing them to contract
electrical impulses reach the atrioventricular node, delays impulse for 0.1 seconds
after delay and atria finished contracting ventricles contract at the same time
summary
SA node -> AV node -> heart apex -> ventricles
electrocardiogram can be used to display the heart rhythm by graphing the current vs time showing the stages of the cardiac cycle
impulses are carried by the purkinje fibers
structure
structure
structure
endothelium and thick layer of smooth cells which allows them to sustain high pressure when blood is pumped through them
endothelium and thin layer of smooth muscle
endothelium and basal lamina
constricted or dilated to regulate blood flow
maintain blood flow in one direction, valves prevent backflow
very small
thin walls
these structures help promote diffusion of chemicals to organs and tissues
Diffusion
by default molecules want to move from high concentration to low concentration: this movement is characterized by presence of a gradient
circulatory system
Diffusion: random thermal motion of particles of liquids, gases or solids
very slow
moves fluids throughout the organism's body
this allows chemical exchange between fluid and tissues
exchange is facilitated by the interstitial fluid
types of circulation
Single circulation: blood passes through the heart only once in a complete cycle
Double circulation: blood passes through the heart twice in each complete cycle
pressure
Blood pressure
Osmotic pressure
direction
happens in two directions, chemical leave blood and enter the tissue and waste chemicals leave the tissues and enter the blood
pressure blood applies on the walls of the blood vessels
drives fluid out of capillaries into the tissues
pulls fluid back into the capillaries
also called blood proteins
Lymphatic system
maintains proper fluid distribution throughout the body
have valves to prevent backflow
fluid inside is called lymph
also houses immune cells to help fight pathogens when introduced to the body