Human Physiology Lecture 13 - Blood

Red blood cells (RBCs), specialized cells crucial for oxygen transport, lacking a nucleus, mitochondria, and other organelles.

A protein in red blood cells that binds and transports oxygen throughout the body.

The process of moving oxygen from the lungs to the tissues, primarily facilitated by hemoglobin in red blood cells.

The process of red blood cell production in the bone marrow.

The lifespan and replacement of red blood cells. Healthy RBCs live ~120 days before being removed by the spleen.

Cytokines that stimulate the production of blood cells, including red blood cells (erythrocytes).

A specific hematopoietic growth factor crucial for stimulating red blood cell production.

Describes the components of blood, namely plasma, red blood cells, white blood cells, and platelets.

Iron is crucial for hemoglobin production, a protein carrying oxygen in red blood cells.

Normal hemoglobin levels in men's blood are between 13 and 18 grams per deciliter.

Normal hemoglobin levels in women's blood are between 12 and 16 grams per deciliter.

A condition caused by insufficient iron intake, affecting red blood cell production.

A type of white blood cell that primarily fights infections by consuming foreign material.

White blood cells that play a vital role in the immune response, producing antibodies and directly destroying foreign cells.

Folic acid and vitamin B12 are needed for DNA replication, promoting cell production.

A type of anemia caused by deficiencies in vitamin B12, an essential nutrient for DNA replication.

The process where platelets adhere to exposed collagen at a damaged blood vessel, forming a temporary plug to slow bleeding.

A chemical released by healthy blood vessel cells that inhibits platelet aggregation and promotes blood vessel dilation, preventing excessive clotting.

The process by which blood is converted into a solid gel (a clot or thrombus) to stop bleeding effectively, usually around a platelet plug.

A series of enzymatic reactions involving plasma proteins, activated by tissue damage, leading to the formation of a blood clot.

A key enzyme in the coagulation cascade that converts fibrinogen into fibrin, the essential protein for forming a blood clot.

Leukocytes, or white blood cells, are derived from hematopoietic stem cells, similar to red blood cells. They primarily mature in the bone marrow, with T lymphocytes undergoing final maturation in the thymus.

Colony-stimulating factors and interleukins are crucial for regulating the production and development of various blood cells, including leukocytes.

Platelets are cell fragments derived from megakaryocytes. They are smaller than red blood cells and lack a nucleus, but contain essential components for blood clotting.

Hemostasis refers to the processes that control bleeding. The first step is vascular spasm, where blood flow is restricted due to vasoconstriction.

The second step in hemostasis is platelet plug formation. Platelets, also known as thrombocytes, are sticky and aggregate at the site of vessel damage.

Von Willebrand factor is a crucial protein for platelet plug formation. It is secreted by megakaryocytes, platelets, and endothelial cells.

Platelets adhere to the exposed collagen fibers in damaged vessels through vWf, forming the initial anchor for platelet aggregation.

Activated platelets release serotonin, epinephrine, and ADP, which further increase their stickiness and trigger the production of thromboxane A2, resulting in more aggregation.

Tissue factor pathway inhibitor (TFPI) is a protein secreted by healthy endothelial cells that specifically inhibits the extrinsic pathway of coagulation, preventing the formation of a blood clot.

Thrombomodulin is a protein secreted by healthy endothelial cells that binds to thrombin, forming a complex that activates protein C, an anticoagulant that inhibits both the intrinsic and extrinsic clotting pathways.

Plasmin, an enzyme, breaks down fibrin, the protein that forms the meshwork of a blood clot, dissolving the clot. Plasminogen is activated into plasmin by plasminogen activators, like tissue plasminogen activator (TPA).

Hemophilia is a genetic disorder caused by a deficiency in specific clotting factors, most commonly Factor VIII, leading to prolonged bleeding episodes.

Low doses of aspirin act as an anticoagulant by inhibiting the formation of thromboxane A2 (TXA2), reducing platelet aggregation and clot formation.