Circulatory Systems Flashcards
What do all animals need for survival?
Oxygen and nutrients
Waste products must also be removed.
What type of circulatory system is found in small animals like arthropods?
Open circulatory system
In this system, blood flows freely over tissues through a haemocoel.
How does blood flow in an open circulatory system?
Freely over tissues, through an open cavity
Blood flows slowly at low pressure.
What type of circulatory system is found in complex animals, including vertebrates?
Closed circulatory system
Blood flows continuously in a system of vessels.
What are the main types of vessels in a closed circulatory system?
Arteries, veins, and capillaries
Blood leaves the heart under pressure into arteries.
What is one advantage of a closed circulatory system?
Blood can be circulated at a higher pressure
This allows for quicker flow to different body parts.
How can blood flow be controlled in a closed circulatory system?
By dilating or constricting blood vessels
This directs blood to areas where it is most needed.
What is single circulation?
A system where the heart is a single pump that only pumps deoxygenated blood
Found in organisms like fish and earthworms.
How does blood circulate in fish during single circulation?
Pumped to gills for oxygen, then to the rest of the body
Blood returns to the heart after circulating.
What is double circulation?
A system where the heart acts as a double pump
Found in birds and mammals, allowing for efficient oxygen delivery.
What happens to blood after it circulates around the body in double circulation?
It is pumped to the lungs to absorb oxygen
Blood then returns to a different side of the heart.
What is the purpose of double circulation?
To maintain a high rate of oxygen-rich blood for high levels of activity
This is essential for the metabolic demands of birds and mammals.
What are the two main types of circulation in the human circulatory system?
Systemic circulation and pulmonary circulation
Systemic circulation delivers oxygen to the body, while pulmonary circulation transports blood to the lungs for oxygenation.
What are the two sides of the heart called?
Left side and right side
Each side of the heart has specific functions in the circulatory system.
What are the four chambers of the heart?
Left atrium, left ventricle, right atrium, right ventricle
The left atrium and ventricle contain oxygenated blood, while the right atrium and ventricle contain deoxygenated blood.
What is the function of valves in the circulatory system?
Ensure blood flows forwards and prevent backflow
Valves are crucial for maintaining the direction of blood flow in the heart and veins.
What causes high pressure in the circulatory system?
Pumping action of the heart, contraction of skeletal muscles, inhalation movements
These factors contribute to the movement of blood from high pressure to low pressure areas.
Fill in the blank: The right ventricle pumps blood to the lungs via the _______.
Pulmonary artery
This is part of the pulmonary circulatory loop.
Fill in the blank: The left ventricle pumps oxygenated blood to the body via the _______.
Aorta
This is part of the systemic circulatory loop.
Where is the human heart located?
In the thoracic cavity above the diaphragm and between the lungs
The heart is protected by the ribs and sternum.
What is the pericardium?
A double walled membrane that encloses the heart
The pericardium provides protection and support to the heart.
What is the myocardium?
The actual heart muscle layer made up of cardiac muscle tissue
The myocardium is responsible for the contraction of the heart.
True or False: The upper end of the heart is narrower than the lower end.
False
The upper end of the heart is wider than the lower end, which points down and to the left.
What type of circulatory system does the human heart have?
Double circulatory system
It consists of two separate pumps for pulmonary and systemic circulation.
What is the function of the right side of the human heart?
Pumps oxygen-depleted blood to the lungs
This process is known as pulmonary circulation.
What is the function of the left side of the human heart?
Pumps oxygen-rich blood to the body
This process is known as systemic circulation.
What is the role of the atrium in the heart?
Receives blood before it is pumped into the ventricle
The plural of atrium is atria.
What happens to the heart valves during a heartbeat?
They open and close to ensure one-way blood flow
Valves react to the different blood pressures on each side.
How many heart valves are there?
Four heart valves
Additionally, there are many valves found in the veins.
What is the tricuspid valve?
Valve between the right atrium and ventricle
It helps regulate blood flow from the right atrium to the right ventricle.
What is the bicuspid valve also known as?
Mitral valve
It is located between the left atrium and left ventricle.
What are the two semilunar valves in the heart?
Pulmonary and aortic valves
These valves are located at the exits of the right and left ventricles.
What are the main types of blood vessels in the circulatory system?
Arteries, veins, capillaries
Small arteries and veins are called arterioles and venules respectively.
What is the inner cell layer of blood vessels called?
Endothelium
It lines the interior surface of circulatory vessels.
What is unique about the endothelium in capillaries?
It is a single layer of squamous cells
This structure forms a barrier between vessels and tissue.
What do arteries do?
Carry blood away from the heart
Blood in arteries is under high pressure as it is pumped by the heart.
What structural features allow arteries to withstand high pressure?
Thick muscular walls, elastic fibers, narrow lumen
These features enable arteries to stretch under pressure and maintain blood flow.
What is the function of smooth muscle fibers in arteries?
Contract to push blood along
This contraction helps maintain blood flow.
What do veins do?
Carry blood back to the heart
Blood in veins is at a much lower pressure compared to arteries.
How do the structural features of veins differ from those of arteries?
Wider and thinner walls
Veins do not need to withstand high pressure like arteries.
What are capillaries?
Very narrow thin blood vessels
Capillaries are the site of exchange for oxygen, carbon dioxide, and nutrients.
What is the primary function of capillaries?
Exchange of substances
They allow diffusion of oxygen, carbon dioxide, and nutrients due to their thin walls.
What is blood composed of?
Blood plasma, red blood cells, white blood cells, platelets
Each component has distinct roles in the circulatory system.
What is plasma?
Light yellow liquid that carries water, salts, and enzymes
Plasma transports nutrients, hormones, and waste products.
What role does plasma play in the body?
Transports nutrients and removes waste
It carries all blood components through the circulatory system.
What are red blood cells also known as?
Erythrocytes
They are typically biconcave discs without a nucleus.
What is the function of hemoglobin in red blood cells?
Transport oxygen and carbon dioxide
Hemoglobin gives red blood cells their color.
What are white blood cells also known as?
Leucocytes
They are involved in the immune response.
What is the primary function of white blood cells?
Protect the body against infectious diseases and foreign invaders
They are produced from stem cells in the bone marrow.
What are platelets?
Tiny cell fragments that help form clots
They are crucial for stopping bleeding when blood vessels are damaged.
What happens when a blood vessel is damaged?
Platelets rush to the site and form a clot
This process helps to fix the damage and prevent excessive bleeding.
Fill in the blank: Capillaries are only ______ thick.
one squamous endothelial cell
This structure allows for efficient diffusion of substances.
What is the function of lymph vessels?
Transport body fluid called lymph
Lymph vessels are part of the lymphatic system, which works alongside the circulatory system.
Name the three important body fluids involved in the circulatory system.
- Blood plasma
- Tissue fluid
- Lymph
Each fluid has a distinct role in the body’s circulatory and lymphatic systems.
What is blood plasma?
Part of the blood in blood vessels
Blood plasma is responsible for transporting nutrients and oxygen.
What is tissue fluid?
The fluid between cells of the body tissues
Tissue fluid is derived from blood plasma and contains both nutrients and waste.
What is lymph?
The fluid found in the lymphatic vessels
Lymph is typically rich in waste products.
How does tissue fluid relate to lymph?
Excess tissue fluid drains into lymph capillaries to become lymph
This process helps maintain fluid balance in the body.
What distinguishes blood plasma, tissue fluid, and lymph?
Their locations and contents
Blood plasma is rich in oxygen and nutrients, tissue fluid contains nutrients and wastes, and lymph is rich in waste products.
What role do lymph nodes play in the lymphatic system?
Filter lymph and remove microorganisms and foreign bodies
Lymph nodes are critical for immune function.
Where are groups of lymph nodes located in the body?
- Neck
- Under the arms
- Chest
- Abdomen
- Groin
These locations are strategic for filtering lymph throughout the body.
What is the function of the spleen in the lymphatic system?
Filters worn-out red blood cells and produces white blood cells (lymphocytes)
The spleen plays a key role in immune response and blood filtration.
What are tonsils?
Masses of lymphoid tissue in the throat region that help to fight infection
Tonsils are part of the immune system and act as the first line of defense against pathogens.
How does lymph return to the circulatory system?
Main lymphatic vessels empty lymph back into the subclavian veins via lymphatic ducts
This process allows lymph to re-enter the blood circulation as blood plasma.
What is the function of lymph vessels?
Transport body fluid called lymph
Lymph vessels are part of the lymphatic system, which works alongside the circulatory system.
Name the three important body fluids involved in the circulatory system.
- Blood plasma
- Tissue fluid
- Lymph
Each fluid has a distinct role in the body’s circulatory and lymphatic systems.