Blood and The Heart Flashcards
What are the two types of circulation systems?
Open Circulatory System, Closed Circulatory System
Open circulatory system: Blood leaves blood vessels and flows around the cells of the animal’s body before re-entering blood vessels. Closed circulatory system: Blood remains in a continuous system of blood vessels.
What are the main components of a human circulatory system?
- Veins & venules
- Capillaries
- Heart
- Blood
- Arteries & arterioles
These components work together to circulate blood throughout the body.
What is the function of arteries in the circulatory system?
Carry blood under high pressure away from the heart
Arteries have thick elastic walls to withstand high pressure.
What is the function of veins in the circulatory system?
Carry blood under low pressure towards the heart
Veins have valves to prevent backflow of blood.
What advantages does a closed circulatory system provide for humans?
- Blood is pumped faster around the body
- Blood flow can be increased to certain parts of the body, e.g. the legs when running
These advantages are crucial for efficient functioning during physical activities.
Fill in the blank: Blood leaves _______ and flows around the cells of the animal’s body before re-entering blood vessels.
blood vessels
This describes the open circulatory system.
True or False: In a closed circulatory system, blood flows freely around body cells without returning to blood vessels.
False
Blood remains in a continuous system of blood vessels in a closed circulatory system.
What prevents arteries from over-expansion?
Inelastic protein (Collagen)
This structural component helps maintain the integrity of arterial walls.
What allows blood vessels to contract and dilate?
Muscle & Elastic Fibres
These fibres play a crucial role in regulating blood flow and pressure.
Fill in the blank: Capillaries are the smallest blood vessels where _______ occurs.
exchange of gases and nutrients
Capillaries are critical for the exchange of materials between blood and tissues.
What type of blood does the left side of the heart contain?
Oxygenated blood
What type of blood does the right side of the heart contain?
Deoxygenated blood
What structure separates the left and right sides of the heart?
Septum
What are the two main circuits of blood circulation?
- Pulmonary circuit
- Systemic circuit
What is the role of the pulmonary circuit?
Heart -> lungs -> heart
What is the role of the systemic circuit?
Heart -> rest of the body -> heart
What is the function of the coronary arteries?
Supply blood to the heart muscle
What is the function of the coronary veins?
Take blood away from the heart muscle
What is a pulse?
The rhythmic expansion and contraction of the wall of the artery at a rate at which the heart beats
What is the pacemaker of the heart composed of?
- SA node
- AV node
Where is the SA node located?
In the wall of the right atrium
Where is the AV node located?
In the wall of the heart, between the right atrium and the right ventricle
What does the SA node stimulate?
The AV node
What happens when the SA node sends an impulse?
Causes the atria to contract
What happens when the AV node sends impulses down the septum?
Causes the ventricles to contract
What is the function of the bicuspid valve?
Separates the left atrium from the left ventricle
What is the function of the tricuspid valve?
Separates the right atrium from the right ventricle
What is the main benefit of double circulation?
- Oxygen-rich and oxygen-poor blood is separated
- Blood pressure remains high to reach all parts of the body
What is a portal system?
A blood pathway that begins and ends in capillaries
What does the hepatic portal system connect?
Stomach and intestines to the liver
What is the role of the semilunar valve?
Prevents backflow of blood from the arteries into the ventricles
What type of muscle is cardiac muscle?
Does not tire
What initiates the heartbeat?
The SA node sends impulses to the atria
The SA node is the natural pacemaker of the heart.
What happens during atrial systole?
The atria contract and the bicuspid and tricuspid valves open
This allows blood to flow into the ventricles.
What is the role of the AV node?
It sends impulses to the ventricles, causing them to contract
This leads to the closing of the tricuspid and bicuspid valves.
What occurs during ventricular diastole?
The ventricles relax and the semilunar valves close
This marks the end of one complete heartbeat cycle.
Define blood pressure.
The force that the blood exerts on the wall of a blood vessel
It is an important measure of cardiovascular health.
How does smoking affect the circulatory system?
Increases heart rate, blood pressure, and chance of clots
Smoking has detrimental effects on cardiovascular health.
What is the effect of high salt intake on blood pressure?
Raises blood pressure
This can lead to hypertension and other cardiovascular issues.
How does exercise influence the circulatory system?
Improves circulation and strengthens the heart
Regular exercise is crucial for maintaining cardiovascular health.
What is plasma?
The liquid part of blood
Plasma consists of water, proteins, and dissolved materials.
What are red blood cells (erythrocytes) primarily responsible for?
Oxygen transport
They contain hemoglobin which converts to oxyhemoglobin.
What is the shape of red blood cells?
Biconcave
This shape provides a larger surface area for gas exchange.
What distinguishes white blood cells (leukocytes) from red blood cells?
Larger size and presence of a nucleus
They play a crucial role in the immune response.
What are the two main types of white blood cells?
Lymphocytes and monocytes
Each type has specific functions in the immune system.
What are platelets (thrombocytes)?
Cell fragments that clot blood
They are essential for preventing blood loss and entry of microorganisms.
Why is it important to know a person’s blood type?
For blood transfusions
Mismatched blood types can cause serious complications.
List the blood types.
- A
- B
- AB
- O
These types are determined by the presence of specific antigens.
What does Rhesus + indicate?
Presence of factor D antigen on red blood cells
This is an important factor in blood typing.
What does Rhesus - indicate?
Absence of factor D antigens
Understanding Rhesus factor is crucial for pregnancy and transfusions.
What problems can arise during pregnancy related to Rh factor?
If mother is Rh- and baby is Rh+
This condition can lead to hemolytic disease of the newborn.
What distinguishes the front (ventral) surface of the heart from the back (dorsal) surface?
The front is more rounded
This anatomical feature is important for identifying the orientation of the heart.
What is the characteristic of the wall of the left ventricle?
The wall is firmer and has thick walls
This allows the left ventricle to pump blood at high pressure to the body.
What is the function of the bicuspid valve?
It separates the left atrium from the left ventricle
Also known as the mitral valve.
What holds the valves in place in the heart?
White strings
These are chordae tendineae that connect the valves to the heart muscles.
What is the characteristic of the wall of the right ventricle?
Thick walls, but thinner than the left ventricle
This structure supports its function of pumping blood to the lungs.
What valve separates the right atrium from the right ventricle?
Tricuspid valve
This valve prevents backflow of blood into the atrium.
What is the characteristic of the walls of the atria?
Thin walls
This allows for easy filling of the atria with blood.
What valves are located at the aorta?
Semilunar valves
These valves prevent backflow of blood into the ventricles.
What valves are located at the pulmonary artery?
Semilunar valves
They perform the same function as those at the aorta.
What structure is located between the right and left sides of the heart?
The septum
It separates oxygenated and deoxygenated blood.
Where does the coronary artery run?
From the aorta to the right ventricle
This artery supplies blood to the heart muscle itself.
