Human Biology - Chapter 5 The circulatory system transports materials throughout the body

What is the liquid component of blood?

Plasma is the liquid part of blood.

What are the components of the formed elements in blood?

The formed elements in blood include erythrocytes (red blood cells), leucocytes (white blood cells), and thrombocytes (platelets).

What are the main types of white blood cells found in blood?

White blood cells in blood consist of various types, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils.

What is the function of erythrocytes in blood?

Erythrocytes, or red blood cells, are responsible for transporting oxygen from the lungs to the body's tissues and organs.

What is the primary role of thrombocytes in blood?

Thrombocytes, also known as platelets, play a crucial role in blood clotting and the prevention of excessive bleeding.

What is plasma, and what substances are dissolved in it?

Plasma is a mixture of water with dissolved substances like sugar and salts.

What is the primary function of plasma in the blood?

The primary function of plasma is to transport various blood components, including cells, nutrients, wastes, hormones, proteins, and antibodies throughout the body.

What type of blood cells are the most abundant in the bloodstream?

Erythrocytes, or red blood cells, are the most abundant cells in the blood.

Describe the shape of erythrocytes (red blood cells).

Erythrocytes have a biconcave shape, meaning they are flattened in the middle on both sides.

What is the significance of red blood cells not having a nucleus?

The lack of a nucleus in red blood cells increases their flexibility and their ability to move through blood vessels.

What is the average lifespan of erythrocytes (red blood cells)?

Erythrocytes have an average lifespan of only 120 days.

What is the primary function of erythrocytes in the bloodstream?

The primary function of erythrocytes is to transport oxygen from the lungs to the cells throughout the body.

What is the overall function of blood as a transport medium?

Blood serves as a transport medium to carry essential components like cells, nutrients, wastes, hormones, proteins, and antibodies throughout the body.

What role do leucocytes, or white blood cells, play in the body?

Leucocytes, or white blood cells, play an important role in protecting the body from infection.

What is the proportion of white blood cells in the blood compared to red blood cells?

White blood cells make up only 1% of the blood, and they are larger than red blood cells.

Name five different types of leucocytes.

There are five different types of leucocytes: Neutrophils, Monocytes, Lymphocytes, Basophils, and Eosinophils.

What is the function of platelets, also known as thrombocytes?

Platelets, or thrombocytes, form a scaffold for the coagulation of blood to create a clot when a blood vessel is injured.

How is the majority of oxygen transported in the blood?

The majority of oxygen is transported on erythrocytes as oxyhaemoglobin.

What is the main protein responsible for oxygen transport in red blood cells?

Hemoglobin is the main protein responsible for oxygen transport in red blood cells.

Why are red blood cells well-suited for the function of oxygen transport?

Red blood cells are well-suited for oxygen transport because they contain hemoglobin, have no nucleus (providing more room for hemoglobin molecules), and are shaped like biconcave discs, increasing surface area for oxygen exchange and providing a large volume for hemoglobin molecules.

How does the absence of a nucleus in red blood cells contribute to their function?

The absence of a nucleus in red blood cells allows for more room for hemoglobin molecules, enhancing their ability to transport oxygen effectively.

What is the significance of the biconcave shape of red blood cells for oxygen transport?

The biconcave shape of red blood cells increases the surface area for oxygen exchange and provides a larger volume to accommodate hemoglobin molecules, making them efficient at oxygen transport.

How is carbon dioxide primarily transported in the bloodstream?

Carbon dioxide is primarily transported in the bloodstream as bicarbonate ions (70%) in the plasma.

What is the second most common way carbon dioxide is transported in the blood?

Carbon dioxide is transported in the blood as carbaminohaemoglobin (22%), which is a combination of carbon dioxide and hemoglobin.

What percentage of carbon dioxide in the blood is dissolved in plasma?

About 7-8% of carbon dioxide is transported by dissolving in plasma.

Which of the three main methods of carbon dioxide transport in the blood involves the conversion of carbon dioxide into bicarbonate ions?

The primary method of carbon dioxide transport in the blood, which involves the conversion of carbon dioxide into bicarbonate ions, is responsible for 70% of transport.

What does the term "carbaminohaemoglobin" refer to in the context of carbon dioxide transport?

"Carbaminohaemoglobin" refers to the combination of carbon dioxide and hemoglobin in the blood, accounting for approximately 22% of carbon dioxide transport.

What are nutrients, and how are they transported in the blood plasma?

Nutrients are essential elements and molecules obtained from the food we eat. Inorganic nutrients are transported as ions in the blood plasma, including sodium ions (Na+), calcium ions (Ca2+), potassium ions (K+), chloride ions (Cl–), and iodide ions (I–). Organic nutrients like glucose, vitamins, amino acids, fatty acids, and glycerol are also dissolved in the blood plasma.

What is the purpose of transporting nutrients in the blood plasma?

Nutrients are transported in the blood plasma to provide essential elements and molecules to cells throughout the body, supporting various metabolic processes.

What are metabolic wastes, and why are they transported in the blood plasma?

Metabolic wastes are substances produced by cells that cannot be used and would be harmful if allowed to accumulate. They are transported in the blood plasma to be carried away from the cells and eventually eliminated from the body.

Name some important inorganic ions dissolved in the blood plasma.

Important inorganic ions dissolved in the blood plasma include sodium ions (Na+), calcium ions (Ca2+), potassium ions (K+), chloride ions (Cl–), and iodide ions (I–).

What are some examples of organic nutrients found in the blood plasma?

Organic nutrients dissolved in the blood plasma include glucose, vitamins, amino acids, fatty acids, and glycerol.

What are some of the most important organic wastes transported in the blood plasma?

What are some of the most important organic wastes transported in the blood plasma?

What are the key components involved in blood clotting?

1. Vasoconstriction

2. Platelet plug

3. Coagulation

What is the initial step in the blood clotting process after an injury to blood vessels?

1. Vasoconstriction

What is the second step in the blood clotting process following vasoconstriction?

Platelet plug

What is the final step in the blood clotting process that ultimately forms a stable clot?

Coagulation

Why is blood clotting essential after an injury?

To minimize blood loss and prevent infection by sealing damaged blood vessels.

Where is the heart located in the body?

The heart is located between the two lungs in the mediastinum.

What is the membrane that encloses the heart and holds it in place?

The heart is enclosed in a membrane called the pericardium.

What is the composition of the heart's wall?

The wall of the heart is made up of cardiac muscle.

What separates the left and right sides of the heart?

The left and right sides of the heart are separated by a wall called the septum.

What is the function of the right side of the heart?

The right side of the heart collects blood from the body and pumps it to the lungs.

What is the function of the left side of the heart?

The left side of the heart receives blood from the lungs and pumps it to the rest of the body.

How many chambers are there in the heart, and what are they called?

The heart has four chambers. The top chambers are called atria, and the bottom chambers are the ventricles.

What is the function of the right atrium in the heart?

The right atrium receives blood from the body and passes it to the right ventricle.

Where does the right ventricle pump blood to?

The right ventricle pumps blood to the lungs.

What is the role of the left atrium in the heart?

The left atrium receives blood from the lungs and passes it to the left ventricle.

Where does the left ventricle pump blood to?

The left ventricle pumps blood to the body.

How many chambers are there in the heart?

There are four chambers in the heart.

What are the top chambers of the heart called?

The top chambers of the heart are called atria.

What are the valves located between the atria and the ventricles called?

The valves located between the atria and the ventricles are called atrioventricular valves.

Where are the semilunar valves located in the heart?

The semilunar valves are located at the exit of the ventricles in the heart.

What is the function of atrioventricular valves and semilunar valves in the heart?

Atrioventricular valves and semilunar valves in the heart act to stop blood from flowing backwards.

What is the function of blood vessels in the circulatory system?

Blood vessels carry blood from the heart to the cells of the body or the lungs and bring it back to the heart, facilitating the circulation of blood.

What is the term used to describe the continuous movement of blood through the heart and blood vessels?

The continuous movement of blood through the heart and blood vessels is referred to as circulation

Name the three main types of blood vessels in the circulatory system.

The three main types of blood vessels are arteries, capillaries, and veins.

What are arteries, and what is their primary function?

Arteries are blood vessels that carry blood away from the heart, primarily distributing oxygenated blood to the body's tissues.

Which artery is the largest in the body, and where does it transport blood from and to?

The largest artery is the aorta, and it carries blood from the left ventricle of the heart to the body's various tissues and organs.

What is the function of the pulmonary artery, and where does it transport blood to and from?

The pulmonary artery carries deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation.

The pulmonary artery carries deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation.

Arteries have smooth muscle in their walls.

How do very large arteries that receive blood from the ventricles further branch into smaller vessels?

Very large arteries divide into smaller arteries, which in turn divide into very small arteries known as arterioles.

What is the role of arterioles in the circulatory system?

Arterioles supply blood to the capillaries, facilitating the exchange of nutrients and gases between the blood and the body's tissues.

What are capillaries, and what is their function in the circulatory system?

Capillaries are microscopic blood vessels that form a network to carry blood close to nearly every cell in the body. They enable cells to obtain their requirements from the blood and pass their waste into the blood, acting as a link between arteries and veins.

What is the structure of capillary walls?

Capillary walls have only one layer of cells, which allows substances to pass easily between the blood and the surrounding cells.How do capillaries contribute to the exchange of substances between blood and surrounding cells?

How do capillaries contribute to the exchange of substances between blood and surrounding cells?

Capillaries facilitate the exchange of substances between blood and surrounding cells due to their thin walls with only one layer of cells, enabling efficient transfer of nutrients, oxygen, and waste products.

What is the primary function of veins in the circulatory system?

Veins carry blood towards the heart.

What is the term for the small veins that capillaries join into?

Venules are the small veins that capillaries join into.

What are the two main veins that bring blood from the body to the right atrium of the heart?

The inferior vena cava and superior vena cava bring blood from the body to the right atrium.

Where do the pulmonary veins bring blood from, and how many are there?

Pulmonary veins bring blood from the lungs to the left atrium, and there are four pulmonary veins – two from each lung.

Why do many veins have valves, and what is their purpose?

Many veins have valves to prevent blood from flowing backward due to the relatively low blood pressure in veins.

Why is it necessary for blood flow to and from cells to be able to change?

Blood flow must be adaptable because cell requirements vary based on their level of activity.

What are the two ways blood flow to and from cells can change?

Blood flow can change by altering the output of blood from the heart and by adjusting the diameter of blood vessels supplying the tissues.

How can blood flow be modified by changing the output of blood from the heart?

Blood flow can be altered by increasing or decreasing the amount of blood ejected from the heart into the circulatory system.

What is the second method for changing blood flow to cells?

The second method involves modifying the diameter of the blood vessels that supply the tissues, either constricting or dilating them as needed.

Why is it important for blood flow to adapt to cell needs?

To ensure that cells receive the necessary oxygen and nutrients, blood flow must adjust to varying levels of cell activity.

What is the cardiac cycle?

The cardiac cycle is the sequence of events that occurs in one complete beat of the heart.

What is systole in the context of the cardiac cycle?

Systole is the pumping phase of the cardiac cycle when the heart muscle contracts.

What is diastole in the context of the cardiac cycle?

Diastole is the filling phase of the cardiac cycle when the heart muscle relaxes.

What happens when both atria and ventricles are in diastole?

During this phase, the atria fill with blood, and the ventricles also receive blood as the valves between them are open.

What is atrial systole, and when does it occur in the cardiac cycle?

Atrial systole is the contraction of the atria, and it occurs after both atria and ventricles are in diastole. It forces the remaining blood into the ventricles.

What happens during ventricular systole in the cardiac cycle?

Ventricular systole forces blood into the arteries.

How do the left and right sides of the heart operate during the cardiac cycle?

Although the left and right sides of the heart are two pumps, they operate together. Both atria contract simultaneously, as do both ventricles.

What factors influence how quickly blood flows around the body?

The speed of blood flow depends on the heart rate and stroke volume.

What is heart rate?

Heart rate is the number of times the heart beats per minute.

What is stroke volume?

Stroke volume is the volume of blood forced from a ventricle of the heart with each contraction.

What is cardiac output, and how is it calculated?

• Cardiac output is the amount of blood leaving one of the ventricles every minute. It is calculated by multiplying stroke volume by heart rate.

• Formula: Cardiac output (mL/minute) = stroke volume (mL) × heart rate (beats/minute)

What are the molecules on the surface of red blood cells that stimulate the immune system called?

Antigens

What is the protein produced by the immune system in response to antigens on red blood cells?

Antibody

What happens when antigens and antibodies combine on the surface of red blood cells?

They form a complex and cause a reaction.

Which blood group systems are particularly important in blood transfusions?

ABO and Rh groupings

What are the two key blood group systems important in blood transfusions?

ABO and Rh

What type of molecules coat the surface of red blood cells and can stimulate the immune system?

Sugar and protein molecules

What is the significance of ABO and Rh groupings in the context of blood transfusions?

They are essential for determining blood compatibility and preventing adverse reactions in transfusions.

How many sugar antigens are involved in the ABO blood group classification, and what are they?

There are two sugar antigens involved in the ABO classification: antigen A and antigen B.

What are the four ABO blood groups, and what antigens are present on the surface of red blood cells for each group?

The four ABO blood groups are group A (antigen A), group B (antigen B), group AB (both antigens A and B), and group O (neither antigen A nor B).

How is a person's ABO blood group determined, and is it inherited?

A person's ABO blood group is determined by their DNA and is inherited.

What antibodies react against antigen A and antigen B in the ABO blood group system?

The antibody that reacts against antigen A is called anti-A, and the antibody that reacts against antigen B is called anti-B.

How does a person's immune system respond to their own antigens in the ABO blood group system?

A person's immune system recognizes their own antigens and does not produce antibodies against them.

What antibodies can a group A person produce, and why?

A group A person can produce only the antibody anti-B because they do not have antigen B on their red blood cells.