red blood cell
Definition
Red blood cells (RBCs) are the most abundant type of blood cell, making up about 45% of the total volume of blood. They are responsible for carrying oxygen from the lungs to the tissues and carbon dioxide from the tissues back to the lungs. RBCs are also important for regulating blood pH and temperature.
RBCs are produced in the bone marrow by a process called erythropoiesis. This process begins with a stem cell that divides into a proerythroblast. The proerythroblast then divides into several more cell types, eventually becoming an RBC.
RBCs are biconcave disks, meaning that they are indented on both sides. This shape gives them a large surface area to volume ratio, which is important for gas exchange. RBCs also contain haemoglobin, a protein that binds oxygen.
RBCs have a lifespan of about 120 days. After this time, they are destroyed by the spleen and liver. The iron from haemoglobin is recycled and used to make new RBCs.
RBC disorders can be caused by a number of factors, including genetic mutations, infections, and diseases. Some common RBC disorders include anaemia, sickle cell disease, and thalassemia.
Anaemia is a condition in which the body does not have enough RBCs. This can lead to symptoms such as fatigue, shortness of breath, and pale skin. Sickle cell disease is a genetic disorder that causes RBCs to be misshapen. This can lead to problems with blood flow and oxygen delivery. Thalassemia is another genetic disorder that affects the production of haemoglobin. This can lead to anaemia and other health problems.
RBC disorders can be treated with medication, blood transfusions, or surgery. The treatment depends on the specific disorder.
How can the word be used?
The patient has a low number of red blood cells.
Different forms of the word
Noun:
- a type of blood cell that contains haemoglobin, which gives blood its red colour.
- The word "red blood cell" is a compound word, made up of the words "red" and "blood cell".
Adjective:
- of or relating to red blood cells.
Etymology
The word "red" comes from the Old English word "reád", which also means "red".
The word "blood" comes from the Old English word "blōd", which also means "blood".
The word "cell" comes from the Latin word "cella", which means "small room".
The first recorded use of the word "red blood cell" was in the 17th century.
The word "red" comes from the Old English word "reád", which also means "red".
The word "blood" comes from the Old English word "blōd", which also means "blood".
The word "cell" comes from the Latin word "cella", which means "small room".
The first recorded use of the word "red blood cell" was in the 17th century.
Question
What do red blood cells do?
AQA Science Exam Question and Answer
Question:
Explain the unique structure and function of red blood cells in the human body, and discuss their role in oxygen transport.
Answer:
Red blood cells (RBCs) are specialised cells in the human body responsible for carrying oxygen from the lungs to various tissues and organs. Their unique structure and function make them highly effective in this role. RBCs lack a nucleus and most organelles, allowing them to have a biconcave shape that increases their surface area, facilitating the exchange of oxygen and carbon dioxide.
Haemoglobin, a protein found within RBCs, is crucial for their oxygen-carrying capacity. Haemoglobin binds to oxygen in the lungs, forming oxyhemoglobin, and releases it when RBCs reach body tissues with lower oxygen levels. This oxygen exchange occurs through the bloodstream and is vital for cellular respiration, where cells use oxygen to produce energy.
The biconcave shape of RBCs allows them to be flexible and squeeze through narrow capillaries, ensuring oxygen delivery to even the smallest blood vessels. Their lack of a nucleus and other organelles also creates more space for haemoglobin, enhancing their oxygen-carrying capability.