Haemotological System Flashcards
What are the functions of blood?
Substance distribution, regulation of homeostasis, protection from blood loss and infection.
What is blood made up of?
Erythrocytes, leukocytes and platelets.
What are features of RBCs?
Spectrin is a protein that maintains biconcave shape. Respiratory gas transport.
Hb binds easily and reversibly with oxygen.
What are features of Hb?
4 polypeptide chains - 2 alpha, 2 beta. Each bound to haem group. Each haem group contains Fe.
When oxygen binds to Fe, Hb is now oxyhaemoglobin. When it detaches, becomes deoxyhaemoglobin.
What is the main transport of iron in the body?
Transferin.
How are erythrocytes produced?
By erythropoiesis. Controlled hormonally. Fe essential for Hb synthesis.
Pluripotent haemopoietic stem cells or haemocytoblasts.
What are features of leukocytes?
Important for disease defence as can move out of blood vessels. Contain membrane bound cytoplasmic granules.
What are types of leukocytes?
Granulocytes - neutrophils, basophils, eosinophils.
Agranulocytes - lymphocytes and monocytes.
Summarise features of each type of Granulocyte.
Basophils - contain histamines
Neutrophils - active phagocytes and contain defensins
Eosinophils - lead attack against parasitic worms.
Summarise features of monocytes.
Differentiate into macrophages, which activate lymphocytes.
Why is the adaptive immunity system important?
Controlling infection for first week. Based on clonal selection of lymphocytes, creates memory cells.
What are platelets?
Cytoplasmic fragments of large cells = megakayocytes. Contain chemicals for clotting.
Clotting is known as haemostasis.
What is the process of blood clotting?
- Vascular spasm
- Platelet plug formation
- Coagulation
Why is the vitamin K cycle so important?
Some can be reused for protein carboxylation, reducing dietary needs. Calcium needed to activate clotting factors, so vitamin K dependant carboxylation allows proteins to bind calcium.
