Blood Anatomy and Physiology Flashcards

Vocabulary and key concepts regarding the components, functions, and disorders of blood, including leukocytes, erythrocytes, and the hemostasis process.

Plasma

The liquid matrix of blood, accounting for $47-63\%$ of blood volume and contains electrolytes, gases, proteins, nutrients, and hormones.

Buffy Coat

A component of blood that makes up ~$1\%$ of the total volume and consists of white blood cells and platelets.

Blood Temperature

The physiological temperature of blood is typically $38\,^{\circ}\text{C}$ ($100.4\,^{\circ}\text{F}$), which is slightly warmer than core body temperature.

Blood pH Range

The normal range for blood pH is between $7.35-7.45$.

Albumin

The most abundant plasma protein responsible for transporting lipids, hormones, and electrolytes; also buffers pH and maintains Blood Colloid (Oncotic) Osmotic Pressure.

Fibrinogen

A plasma protein involved in hemostasis, specifically serving as the precursor to fibrin (Factor I) in the coagulation cascade.

Hematopoiesis

The production of blood cells which occurs in the yolk sac, liver, spleen, and thymus of a fetus, but mainly in red bone marrow after birth.

Hematopoietic stem cells (HSC)

Also known as pluripotent stem cells (PSCs), these are the ancestor cells for all formed elements in the blood.

Erythropoietin (EPO)

A hormone produced mainly by the kidneys that stimulates the process of erythropoiesis (red blood cell production).

Erythrocyte

A red blood cell that lacks a nucleus and mitochondria, uses anaerobic fermentation for ATP, and is biconcave in shape to deliver $O_2$ and pick up $CO_2$.

Fetal Hemoglobin

A form of hemoglobin consisting of two alpha and two gamma chains with a higher affinity for $O_2$ than adult hemoglobin.

Adult Hemoglobin

A form of hemoglobin consisting of two alpha and two beta chains, where each chain contains a heme group with iron at its center.

Bilirubin

A yellow pigment produced during the destruction of old RBCs after heme is converted to biliverdin; high levels due to liver loss cause Jaundice.

Anemia

A condition characterized by a decreased oxygen-carrying capacity of the blood due to inadequate erythropoiesis, hemoglobin synthesis, or destruction of red blood cells.

Antigen

A molecule on the cell surface that serves as a cell identifier.

Universal Receiver

Blood Type AB, which has both A and B antigens and no antibodies, allowing it to receive blood from types A, B, AB, and O.

Universal Donor

Blood Type O, which lacks A and B antigens and can donate to types A, B, AB, and O.

RhoGAM

A prophylactic immunoglobulin dose given to Rh- mothers to neutralize the Rhesus antigen (Antigen D) and prevent maternal immune activation against fetal RBCs.

Neutrophils

The most abundant leukocytes ($60-70\%$) which feature $3-5$ lobes and function to phagocytize bacteria.

Eosinophils

Granulocytes that make up $2-4\%$ of leukocytes, feature red-orange granules and a bilobed nucleus, and respond to parasites and allergies.

Basophils

Granulocytes making up ~$0.5\%$ of leukocytes that contain histamine, heparin, and serotonin.

Monocytes

Agranulocytes ($3-8\%$) with horseshoe-shaped nuclei that become macrophages and act as Antigen Presenting Cells.

Lymphocytes

Agranulocytes ($25-35\%$) responsible for adaptive immunity; includes T-lymphocytes (attacking cancer/infected cells) and B-lymphocytes (producing antibodies).

Leukopenia

A leukocyte disorder where the cell count falls below $5,000\,\text{cells}/\mu\text{L}$.

Leukemia

Uncontrolled malignant leukocyte production resulting in cell counts greater than $11,000\,\text{cells}/\mu\text{L}$.

Megakaryocyte

The precursor cell in the bone marrow that produces platelets (thrombocytes) under the influence of thrombopoietin.

Hemostasis

The three-step process by which the body stops bleeding, involving vascular spasm, platelet plug formation, and coagulation.

Thromboxane A2 (TXA2)

A substance produced by activated platelets that promotes further platelet activation and aggregation.

Intrinsic Pathway

A coagulation pathway activated by Factor XII when blood vessel damage exposes internal collagen; involves factors XII, XI, IX, and VIII.

Extrinsic Pathway

A coagulation pathway triggered by tissue damage (Factor III/Tissue Factor) and involving Factor VII.

Fibrinolysis

The resolution of a blood clot where Tissue Plasminogen Activator (tPA) converts plasminogen to plasmin to dissolve fibrin.

Hemophilia A

A coagulation abnormality resulting from a deficiency in Factor VIII, accounting for $85\%$ of hemophilia cases.