BIO 2301 Unit 3 Lecture Exam Study Guide

A comprehensive set of vocabulary flashcards covering Blood components, Respiratory Physiology, Acid-Base Balance, and Thermoregulation for the BIO 2301 Unit 3 exam.

Erythrocytes

Also known as Red Blood Cells (RBCs); the most numerous blood cell type, containing hemoglobin to transport oxygen and remove $CO_2$.

Plasma

The non-living, extracellular fluid matrix of blood; makes up about $55\%$ of blood volume and consists of approximately $90\%$ water.

Albumin

The most abundant plasma protein ($\sim 60\%$) produced by the liver; responsible for maintaining oncotic (osmotic) pressure to retain water in the bloodstream.

Gamma Globulins

Also called immunoglobulins or antibodies; produced by plasma cells and play a key role in identifying and neutralizing pathogens.

Fibrinogen

A soluble plasma protein produced by the liver that is essential for hemostasis; it is converted to fibrin by thrombin to form a mesh.

Bicarbonate Buffer

A system using dissolved ions ($HCO_3^-$) to maintain osmotic balance and regulate blood $pH$.

Hemoglobin

A protein within RBCs that binds to oxygen via an iron molecule in heme pigment; also binds to $CO_2$ and $H^+$ ions.

Neutrophil

The most abundant white blood cell (WBC) which phagocytizes bacteria; levels are elevated during bacterial infections.

Basophil

The rarest granulocyte, involved in inflammation; contains granules with histamine to dilate blood vessels and increase capillary permeability.

Monocyte

The largest WBC; functions in phagocytosis during long-standing infections and becomes a macrophage in tissues.

Megakaryocytes

Large bone marrow cells that produce cytoplasmic fragments known as platelets (thrombocytes).

Hematopoiesis

The process of blood cell formation, occurring in the red bone marrow of flat bones.

Hemocytoblast

A pluripotent stem cell from which all blood cells originate.

Reticulocyte

An immature RBC released into the bloodstream; its count serves as a clinical indicator of RBC production activity.

Erythropoietin (EPO)

A hormone from the kidney released when $pO_2$ levels are low; it stimulates erythropoiesis in the red bone marrow.

Bilirubin

A lipid-soluble substance derived from the porphyrin ring of hemoglobin during RBC destruction in the spleen and liver.

Agglutinogens

Antigens located on RBC membranes that act as "nametags" for the immune system.

Type O Blood

The universal donor type; characterized by having no antigens on RBCs and both Anti-A and Anti-B antibodies in the plasma.

Erythroblastosis Fetalis

Hemolytic Disease of the Newborn (HDN); occurs when maternal anti-Rh antibodies attack fetal RBCs in an Rh+ baby born to an Rh- mother.

Vasospasm

The first phase of hemostasis involving the constriction of a blood vessel at the injury site to decrease blood loss.

Thromboxane $A_2$

A substance released by platelets during plug formation that promotes vasoconstriction and platelet recruitment.

Intrinsic Mechanism

A coagulation pathway triggered by internal injury to the vessel wall, forming a clot in $3\text{--}6$ minutes via factors XII, XI, IX, VIII, and X.

Extrinsic Mechanism

A fast coagulation pathway ($15\text{ seconds}$) triggered by external tissue injury, releasing tissue thromboplastin (Factor III).

TPA (Tissue Plasminogen Activator)

An enzyme released by healed endothelial cells that activates plasminogen into plasmin to dissolve the fibrin mesh.

Boyle’s Law

The physical law stating that pressure varies inversely with volume ($P \propto 1/V$).

Intrapleural Pressure ($P_{ip}$)

Pressure within the pleural cavity; it is always slightly negative ($\sim 756\,\text{mmHg}$) to prevent the lungs from collapsing.

Lung Compliance

The ease with which the lungs can be filled with air ("stretchiness"); decreased in restrictive diseases like fibrosis and increased in emphysema.

Tidal Volume (TV)

The volume of air moved in or out with each normal, resting breath, approximately $500\,\text{mL}$.

Vital Capacity (VC)

The total amount of exchangeable air ($\sim 5000\,\text{mL}$), calculated as $IRV + TV + ERV$.

Anatomical Dead Space

The volume of air ($\sim 150\,\text{mL}$) located in the conducting zones where gas exchange does not occur.

Bohr Effect

A decrease in hemoglobin's affinity for $O_2$, causing increased unloading, triggered by high temperature, high $pCO_2$, and low $pH$.

Carbaminohemoglobin

Hemoglobin bound to carbon dioxide; this method accounts for $20\text{--}23\%$ of $CO_2$ transport in the blood.

Hering-Breuer Reflex

A protective brainstem reflex that inhibits inspiration when the lungs are stretched to prevent over-inflation.

Respiratory Acidosis

A condition resulting from hypoventilation and the retention of $CO_2$, leading to a blood $pH < 7.35$.

ROME Mnemonic

A tool for ABG interpretation meaning "Respiratory Opposite, Metabolic Equivalent," relating $pH$ changes to $CO_2$ (opposite) and $HCO_3^-$ (same direction).

Convection

A heat loss mechanism involving the transfer of heat via the movement of air or liquid across the skin.

Evaporation

The loss of body heat as sweat is converted into vapor; accounts for $25\text{--}30\%$ of heat loss.

Heat Stroke

A life-threatening failure of thermoregulatory mechanisms characterized by a lack of sweating, hot/dry skin, and a dangerously high core temperature.

Pyrogens

Substances like bacterial toxins that trigger PGE2 release in the hypothalamus to reset the body's thermostat to a higher set point.

Bergamot

The magic keyword provided for the extra credit question on the exam.