Anatomy and Physiology 2 - Blood (study questions)

What is the function of blood and what does it contain?

Blood has several important functions in the body. It carries oxygen and nutrients to the cells, removes waste products, fights infections, and helps regulate body temperature. Blood contains red blood cells, white blood cells, platelets, and plasma.

What are the three layers of blood, and what percentage of the total blood volume do they compose?

Blood can be separated into three main layers: plasma, red blood cells, and a thin layer called the "buffy coat" which contains white blood cells and platelets. Plasma makes up about 55% of the blood, red blood cells make up about 45%, and the buffy coat is less than 1%.

What are red blood cells and what do they do?

Red blood cells are the cells in your blood that carry oxygen from your lungs to the rest of your body. They also bring carbon dioxide back to your lungs so you can breathe it out. They are shaped like tiny, flexible discs and are very important for keeping your body working properly.

What is hemoglobin, and what are the different parts of a hemoglobin molecule?

Hemoglobin is a protein in red blood cells that carries oxygen from your lungs to the rest of your body. It has four parts, called subunits, each containing a heme group that holds an iron atom. The iron is what binds to oxygen, allowing hemoglobin to transport it through the blood.

How are old red cells recycled, and how does this relate to jaundice?

Old red blood cells are recycled by the spleen and liver. These organs break down the cells and reuse some parts, like iron, to make new red blood cells. When red blood cells are broken down, a substance called bilirubin is produced. If too much bilirubin builds up in the body, it can cause jaundice, which makes the skin and eyes look yellow.

Why is poop brown, and why is urine yellow?

Poop is brown because of a substance called bilirubin, which is produced when old red blood cells are broken down in the body. Bilirubin is processed by the liver and ends up in the intestines, where it gives poop its brown color. Urine is yellow because of a pigment called urochrome, which is made when the body breaks down old cells and gets rid of waste products through the kidneys.

What are the different white blood cells, and what is the function of each?

White blood cells are cells in your blood that help fight infections and keep you healthy. There are several types:

1. Neutrophils: They are the most common and quickly respond to infections.

2. Lymphocytes: These include T cells and B cells, which help destroy infected cells and produce antibodies.

3. Monocytes: They become macrophages that clean up dead cells and fight infections.

4. Eosinophils: They help fight parasites and are involved in allergic reactions.

5. Basophils: They release chemicals that help control the immune response and are also involved in allergic reactions.

What is in plasma?

Plasma is the liquid part of blood. It is mostly water but also contains proteins, nutrients, hormones, and waste products. It helps transport these substances throughout the body.

How and where are blood cells made?

Red blood cells are made in the bone marrow, which is a spongy tissue inside your bones. The process starts with special cells called stem cells that develop into red blood cells. Your body constantly makes new red blood cells to replace the old ones that get recycled.

How do the kidneys control the rate of hematopoiesis?

The kidneys control the rate of hematopoiesis (the production of blood cells) by releasing a hormone called erythropoietin. When the kidneys sense that the body needs more red blood cells, such as when oxygen levels are low, they release more erythropoietin. This hormone signals the bone marrow to produce and release more red blood cells into the bloodstream.

What is iron-deficiency anemia?

Iron-deficiency anemia is a condition where your body doesn't have enough iron to make a sufficient amount of healthy red blood cells. This can make you feel tired and weak because your blood can't carry enough oxygen to your body's tissues.

What is leukemia, and how is it treated?

Leukemia is a type of cancer that affects the blood and bone marrow, where blood cells are made. It causes the body to produce an excessive number of abnormal white blood cells, which can interfere with the body's ability to fight infections and can crowd out healthy blood cells.

Treatment for leukemia often involves chemotherapy, which uses strong medicines to kill cancer cells. Other treatments might include radiation therapy, targeted therapy that focuses on specific parts of cancer cells, and bone marrow transplants, which replace the damaged bone marrow with healthy marrow from a donor.

What is sickle-cell anemia, and how does it relate to malaria?

Sickle-cell anemia is a genetic condition where red blood cells are shaped like a crescent or sickle instead of being round. This shape makes it harder for the cells to move through blood vessels and can cause pain and other health problems. People with sickle-cell anemia are less likely to get severe malaria, a disease caused by a parasite, because the sickle-shaped cells make it harder for the malaria parasite to survive.

How does hemoglobin’s affinity for oxygen change in different environments?

Hemoglobin's affinity for oxygen changes based on the environment. In the lungs, where there is a lot of oxygen, hemoglobin holds onto oxygen tightly. In the body's tissues, where there is less oxygen, hemoglobin releases the oxygen so the cells can use it. Factors like pH, carbon dioxide levels, and temperature also affect how strongly hemoglobin holds onto or releases oxygen.

How do blood clots form?

Blood clots form when your body tries to stop bleeding. When you get a cut or injury, tiny cells in your blood called platelets stick together at the site of the injury. They form a plug to block the hole. Then, proteins in your blood called clotting factors make a mesh that holds the platelets together, creating a clot to stop the bleeding.