Internal systems Flashcards
What is the function of the tricuspid valve?
Allows blood to flow from the right atrium to the right ventricle
The tricuspid valve is one of the heart’s four valves that ensures unidirectional blood flow.
What type of blood does the pulmonary artery carry?
Deoxygenated blood
The pulmonary artery transports deoxygenated blood from the right ventricle to the lungs for oxygenation.
Where does blood flow from the left atrium?
Into the left ventricle through the mitral valve
The mitral valve is also known as the bicuspid valve.
What does the left ventricle do?
Pumps oxygenated blood into the aorta
This distributes oxygen-rich blood to the rest of the body.
What are the two types of valves in the heart?
Atrioventricular valves and semilunar valves
Atrioventricular valves include the tricuspid and mitral valves; semilunar valves include the pulmonary and aortic valves.
What is the primary function of arteries?
Carries oxygenated blood away from the heart
Arteries have thick elastic walls to withstand high pressure.
What do veins do?
Carries deoxygenated blood back to the heart
Veins have thinner walls and valves to prevent backflow.
What is the smallest type of blood vessel where exchange occurs?
Capillary
Capillaries have thin walls that allow for gas and nutrient diffusion.
What prevents the backflow of blood in veins?
Valves
Valves ensure blood moves in one direction, especially in the limbs.
What does the term ‘double pump heart’ refer to?
The heart pumps blood to two circuits: pulmonary and systemic
The right side pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the body.
What percentage of blood is plasma?
55%
Plasma contains water, proteins, nutrients, waste products, and hormones.
What do erythrocytes do?
Carry oxygen using hemoglobin
Erythrocytes are produced in the bone marrow.
What is the role of leukocytes?
Defend against infection
Leukocytes are part of the immune system.
What is the function of platelets?
Aid in blood clotting
Platelets aggregate at wound sites to initiate clot formation.
How is heart rate controlled?
By the sinus node influenced by the autonomic nervous system
The sympathetic nervous system speeds up heart rate while the parasympathetic slows it down.
What causes the ‘lub’ sound in the heartbeat?
Closure of the atrioventricular valves
The ‘dub’ sound is caused by the closure of the semilunar valves.
What is systolic pressure?
The pressure when the heart contracts
Systolic pressure is the higher number in blood pressure readings.
What factors affect blood pressure?
- Blood volume
- Heart rate
- Vessel diameter
- Elasticity of arteries
- Resistance of blood flow
These factors can influence overall cardiovascular health.
What initiates blood clotting?
Platelets aggregate at the wound site
They release clotting factors triggering a cascade to form a fibrin mesh.
What is the trachea’s primary function?
Connects the larynx to the bronchi
The trachea is lined with ciliated cells to filter air.
What is inhaled air primarily composed of?
High in oxygen and low in carbon dioxide
This composition is critical for efficient gas exchange.
What happens during inhalation?
Diaphragm contracts and moves downward
This decreases pressure in the lungs, allowing air to enter.
What is the role of the medulla oblongata in respiration?
Controls breathing rate by detecting CO2 levels
It is located in the brainstem.
What occurs in the alveoli?
Gas exchange
Oxygen diffuses into the blood and carbon dioxide diffuses out.
