Cytology · MU Sofia

52. Erythrocytes. Erythrocytopoiesis.

Covers erythrocyte structure, including the biconcave shape, the absence of a nucleus and organelles, and the cytoskeletal lattice. It then moves to function and haemoglobin forms such as oxyhaemoglobin, carbaminohaemoglobin and carboxyhaemoglobin, followed by lifespan, splenic removal and iron recycling. Disorders covered include anaemia causes and symptoms and sickle cell disease, before erythropoiesis and erythropoietin regulation are explained. It closes with rouleaux formation and using erythrocyte size to estimate vessel diameter.

Inside: 7 sections · 6 labelled pictures · 13 flashcards · 4 min

Topic 52 of 127 in the MU Sofia syllabus for Cytology (Dental Medicine, Year 1). The free AceMed note covers it in 7 sections, about 623 words (4 min of reading), with 13 flashcards.

In this note

  1. Erythrocytes
  2. Structure
  3. Function
  4. Lifespan and Removal
  5. Disorders
  6. Formation
  7. Other Key Points

Erythrocytes

Erythrocytes, also known as red blood cells (RBCs), are the most abundant cell type in blood and are essential for oxygen transport.

Structure

  • Biconcave shape: This unique shape, resembling a disc with concave surfaces on both sides, provides a larger surface area for efficient oxygen diffusion and enhances flexibility, allowing the cells to squeeze through narrow capillaries.
  • Lack of nucleus and organelles: Mature erythrocytes lack a nucleus and most other organelles, including mitochondria. This allows for more space for haemoglobin, the protein responsible for oxygen transport.
  • Cytoskeletal lattice: The erythrocyte membrane is supported by a cytoskeletal lattice, crucial for maintaining the cell's biconcave shape and flexibility. Defects in this lattice can lead to shape abnormalities and reduced lifespan.

Function

  • Oxygen Transport: The primary function of erythrocytes is to transport oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs. This is achieved through haemoglobin, a protein

that binds to oxygen in high-oxygen locations (lungs) and releases it where oxygen concentration is low (tissues).

  • Haemoglobin: Haemoglobin is a tetrameric protein that consists of four globin chains, each containing a heme group that binds to oxygen. The different types of haemoglobin include:
  • Oxyhaemoglobin (HbO2): The oxygen-loaded form of haemoglobin.
  • Carbaminohaemoglobin: Haemoglobin bound to carbon dioxide.
  • Carboxyhaemoglobin (HbCO): The form of haemoglobin bound to carbon monoxide, which is an irreversible binding that reduces the cell's capacity to transport oxygen. Haemoglobin in general, has a higher affinity for carbon monoxide. Hence, carbon monoxide poisoning is so lethal.

Continue reading free

The whole note, all 7 sections, is free with an AceMed account, with its 13 flashcards. Premium adds flashcard recall, highlights and Ask AI.

Start freeAlready a member? Open the note