A& P Circulation: cardiovascular & lymphatic systems
Describe the pathway of blood through the heart and lungs, beginning at the vena cava.
1. Blood enters the right atrium from the upper and lower body through veins called the superior vena cava and the inferior vena cava. 2. From there it passes trough an ATRIOVENTRICULAR VALVE into the right ventricle. (The purpose of valves is to prevent backflow when the ventricles contract.) 3. The right ventricle pumps blood through the semilunar valve into the PULMONARy ARTERIES, which carry the blood to the lungs. This blood is DEOXYGENATED and become OXYGENATED in the lungs, where the gas exchange occurs. 4. Newly oxygenated blood leaves the lungs via the PULMONARY VEINS, which returns blood to the left atrium. 5. From there, blood passes through another atrioventricular valve to the left ventricle. 6. Muscular contractions of the left ventricle pump blood through the aorta to all parts of the body.
What is the function of arteries?
Arteries transport blood away from the heart. They carry blood at relatively high pressure, so they are muscular. We feel a pulse in the arteries.
Describe the lymphatic system processes and components.
As blood passes through the vessels of the circulatory system, fluid and proteins can leak out. This lost fluid diffuses into LYMPH CAPILLARIES, which are found throughout the cardiovascular system, and it thus enters into the lymphatic system. Inside the lymphatic system, the fluid, or lymph, returns to the circulatory system. LYMPH NODES are special pockets in the lymphatic system where the lymph is filtered. White blood cells are present in these nodes to attack bacteria and viruses that may be present in the fluid. This is why swollen and tender lymph nodes are a sign of infection.
Describe what blood is made up of.
Blood is considered a type of connective tissue that is made up of a variety of cells suspended in a liquid called plasma. Red blood cells, white blood cells, and platelets make up 45% of whole blood (white blood cells and platelets makeup less than <1%), whereas plasma makes up the other 55%.
Explain blood pressure and systole versus diastole.
Blood pressure from the pumping action of the heart forces blood to circulate. Systole (or systolic BP) is when the heart contracts and the pressure increases, blood is pushed out of the heart. Diastole (or diastolic BP) is when the heart relaxes and the pressure is lowered, heart is filled up with blood.
What are the function of capillaries?
Capillaries are tiny blood vessels that connect arteries and veins. Through the capillary walls (only one cell thick), materials enter and leave the blood.
What are platelets?
Found in plasma, they are pieces of cells that are important in blood clotting.
What is plasma?
Plasma makes up 55% of whole blood and contains proteins, ions, hormones, and gases.
What are the function of red blood cells?
Red blood cells, or erythrocytes, are responsible for transporting oxygen, and they do not have nuclei or mitochondria. To suit their main function of transporting oxygen, red blood cells are small & thin (to allow for diffusion), and each cell contains approximately 250 million molecules of hemoglobin, which is an oxygen carrier.
What is pulmonary circulation?
The circulation of blood through the lungs.
What is systemic circulation?
The circulation of blood throughout the body.
What is coronary circulation?
The circulation of blood to the heart.
What are the major components of the cardiovascular system?
The heart, blood vessels, & blood.
What is circulation?
The internal transport of fluid throughout the body, which allows for the exchange of gases, the absorption of nutrients, and the disposal of waste. The circulatory system is made up of the cardiovascular system and the lymphatic system, which function together to achieve these goals.
What is hemoglobin?
The iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates.
What do the atria do?
The two atria (singular: atrium) receive blood.
What do the ventricles do?
The two ventricles pump blood to the body.
What is the function of veins?
Veins transport blood to the heart, and they contain valves to prevent the backflow of blood as it returns to the heart.
What are the function of white blood cells?
Whit blood cells, or leukocytes, are less abundant than red blood cells and are involved in host immune defense. An infection is indicated when the number of white blood cells exceeds the normal concentration.
What are the 3 kinds of blood vessels?
arteries, veins, and capillaries
What 2 systems make up the circulatory system?
cardiovascular system and lymphatic system
