1.7 The circulatory system (ppt) Flashcards
What are the two main components of blood?
- Plasma (55%)
- Cells (45%)
What is plasma primarily composed of?
90% water
What types of cells are found in blood?
- Red blood cells (RBC)
- White blood cells (WBC)
- Platelets
What is the primary function of platelets?
Help blood clot
What protein do platelets produce to form a blood clot?
Fibrin
What happens when a break occurs in a capillary wall?
Clumping of platelets and release of thromboplastin
What does thromboplastin convert prothrombin into?
Thrombin
What is the function of thrombin in blood clotting?
Converts fibrinogen into fibrin
What is the shape of red blood cells?
Biconcave
What is the role of hemoglobin in red blood cells?
Oxygen binds to the hemoglobin.
Carbon dioxide dissolves in the blood.
This allows the blood cells to transport gases through the blood.
Which artery carries deoxygenated blood from the heart to the lungs?
Pulmonary artery
Which vein carries oxygenated blood from the lungs to the heart?
Pulmonary vein
Why is the left ventricle wall thicker than the right?
It pumps blood to all organs except the lungs
What are the four valves of the heart?
- Tricuspid valve
- Pulmonary valve
- Mitral valve
- Aortic valve
What is the function of valves in veins?
Prevent blood from flowing in the wrong direction
What is the primary function of white blood cells?
Fight off infection
What components are dissolved in plasma?
- Proteins
- Minerals
- Salts
- Glucose
- Amino acids
- Cell waste products
What percentage of extracellular fluid returns to capillaries at the venule end?
90%
What are lymph vessels responsible for?
Picking up excess extracellular fluid
What is the cardiac cycle?
The sequence of events of a heartbeat
How thick are capillary walls?
One cell thick
What is the function of capillaries?
Exchange of oxygen, nutrients, and wastes between blood and tissues
What are the three types of blood vessels?
- Arteries
- Capillaries
- Veins
What is unique about the double circulation system in humans?
Blood passes through the heart twice per circulation
What does pulmonary circulation do?
Carries blood to the lungs and back to the heart
What does systemic circulation do?
Carries blood to the body and back to the heart
What is the overall function of the circulatory system?
Transport materials throughout the body
What is the size of the human heart?
About the size of a clenched fist
What type of muscle makes up the heart?
Cardiac muscle
What are the two upper chambers of the heart called?
Atria
What are the two lower chambers of the heart called?
Ventricles
What happens when the right atrium receives oxygen-poor blood?
It flows into the right ventricle
What is the role of the right ventricle?
Forces blood out of the heart to the lungs
What is the function of capillaries in the circulatory system?
Join into larger vessels that form veins
