LECTURE 7a: Blood Components and RBC Lifecycle.

Vocabulary flashcards covering plasma and formed elements, major plasma proteins (globulins and fibrinogen), and the structure and lifecycle of red blood cells (RBCs) including hemoglobin metabolism.

Plasma

The watery extracellular matrix of blood; ~99% water; about 5–6 L in an adult; liquid portion that remains after centrifuging blood.

Formed elements

Cellular components of blood (RBCs, WBCs, platelets) that make up less than 1% of blood volume after centrifugation.

Major plasma proteins

The main proteins in plasma that support transport, regulation, and protection (e.g., globulins, fibrinogen).

Globulins

A family of plasma proteins produced in the liver, divided into alpha, beta, and gamma globulins; functions include transport and immune defense.

Alpha globulins

A subgroup of globulins; primarily transport proteins in plasma.

Beta globulins

A subgroup of globulins; primarily transport proteins in plasma.

Gamma globulins

Immunoglobulins; antibodies produced by plasma cells that help defend against pathogens.

Immunoglobulins

Antibodies; gamma globulins that form part of the body's immune defense.

Interferons

Blood proteins that act as cytokines in the immune response and host defense.

Fibrinogen

A plasma protein that is converted to fibrin during blood clotting.

Erythropoiesis

The production of red blood cells (RBCs) in the bone marrow.

Erythrocyte (RBC)

Red blood cell; most numerous blood cell; designed for oxygen transport; usually a biconcave disc.

Anucleate

Lacking a nucleus; mature red blood cells have no nuclei.

Mitochondria absent

Mature red blood cells lack mitochondria (and other organelles) and rely on glycolysis for energy.

Biconcave disc

The biconcave shape of RBCs that increases surface area and enables flexible passage through capillaries.

Hemoglobin (Hb)

The oxygen-carrying protein inside RBCs; approximately 280 million Hb molecules per cell.

Lifespan of RBCs

Approximately 120 days for a typical red blood cell.

Heme

The iron-containing portion of hemoglobin; its non-iron remainder is converted to bilirubin after RBC breakdown.

Transferrin

A plasma protein that binds iron released from heme and transports it to bone marrow for reuse.

Bilirubin

A yellow-brown pigment formed from the breakdown of heme; excreted in bile and gives feces their color.