Bio 7 - The Circulatory System Flashcards
Is the mammalian Circulatory System Open or Closed ?
Closed
Is the Mammalian Lymphatic system Open or Closed ?
Open
Name five transport functions of the circulatory system
- Hormones from exocrine glands to tissues
- Molecules and Cells for the immune system
- Nutrients from the digestive tract to the liver
- Oxygen from the respiratory system to the cells
- Waste from body cells to the respiratory and excretory systems
Name two functions of the blood in relation to Thermoregulation ?
Distributing heat from Skeletal muscles and other active organs to the rest of the body
Blood is directed towards or away from the skin, depending on whether the body wants to release or conserve heat
Describe the path of deoxygenated blood through the systemic circulation
Deoxygenated blood returns to the heart from all body tissues except the lungs.
Blood enters the right atrium through large veins (Venae Cavae).
Blood is then pumped into the right ventricle via the tricuspid valve.
Blood then enters the Pulmonary circulation through the Pulmonary (Semi-Lunar) valves and Arteries.
Describe the Pulmonary Circulation from the heart
Blood is pumped to the lungs from the right ventricle via the semi-lunar valves and Pulmonary arteries.
The blood loses CO2 and is oxygenated in the lungs and returns through pulmonary veins to the left atrium.
Blood is then pumped through the Mitral (bicuspid) valve to the left (largest) ventricle and into the systemic circulation via the aortic valve and aorta.
Which is the largest Ventricle ? Why ?
The left ventricle because greater pressure is required to pump blood all around the body than to the lungs.
Describe the five different types of blood vessel
Arteries Arterioles Capillaries Venules Veins
Describe the composition of a blood vessel wall
Arteries tend to have thick, smooth, muscular walls as they need to withstand increased pressure.
Veins have thinner walls as they carry blood at lower pressure.
Outer- Adventitia
Middle - Media (muscle)
Inner - Intima
Explain how newly deoxygenated blood enters the right atrium
Deoxygenated blood enters very small Veins (Venules), then flows into larger and larger veins until it enter the Venae Cavae and into the right atrium.
What is the function of the Superior and Inferior Venae Cavae ?
The Superior Venae Cavae drains blood from the Upper body, the inferior from the Lower body.
Explain the muscle pump
Vein walls are thin and floppy, therefore they are often located in or near muscles.
E.g. The movement of the leg squeezes the veins, which pushes the blood through 1-way bicuspid valves towards the heart.
Explain the function of the Coronary Arteries ?
Coronary Arteries branch off the Aorta in order to supply the heart muscle
Explain Systolic and Diastolic blood pressure
Blood pressure is the force exerted by the blood against the inner walls of the vessels (especially arteries).
Systolic is the maximum arterial pressure when the ventricle contracts and blood is pumped into the arterial system.
Diastolic is the minimum pressure when the ventricle is relaxed and blood is returned to the heart via the veins.
What is the pulse pressure ?
The difference between the systolic and diastolic blood pressure