Lab Exam 2 Notes: Key Concepts

Set of vocabulary flashcards covering key concepts from the Lab Exam 2 notes, including the cardiac cycle, respiratory mechanics, blood gas homeostasis, renal function, and digestive physiology.

Cardiac Cycle

The sequence of events in the heart from the beginning of one heartbeat to the beginning of the next.

Right Ventricle

Pumps blood to the lungs through pulmonary circulation.

Left Ventricle

Pumps blood to the body through systemic circulation.

Atrial Systole

Phase when blood enters the ventricles both passively and actively.

Ejection

Process of blood being pumped out of the ventricles into elastic arteries.

Systolic Pressure

Average high pressure during the cardiac cycle.

Diastolic Pressure

Average low pressure during the cardiac cycle.

AV Valve

Atrioventricular valve prevents backflow from the ventricles into the elastic arteries.

SL Valve

Semilunar valve prevents backflow of blood from elastic arteries.

First Heart Sound

Caused by the slamming shut of the atrioventricular valves during systole.

Second Heart Sound

Caused by the slamming shut of the semilunar valves during diastole.

Isovolumetric Relaxation

Phase when pressure within the valves decreases, and once low enough, AV opens.

Passive Filling

When blood begins to enter ventricles while chambers are relaxed.

Active Filling

When atria contract, pumping blood past AV to the ventricles.

Isovolumetric Contraction

Phase that must occur for pressure to increase within valves before ejection.

ECG/EKG

Measure voltage changes in the body due to electrical activity of the heart.

P Wave

Represents depolarization of the atria in an ECG.

QRS Complex

Represents ventricular depolarization in an ECG.

T Wave

Represents ventricular repolarization in an ECG.

PR Interval

Time between the P wave and the beginning of the QRS complex.

AV Nodal Block

Delay in action potential at the atrioventricular node.

ST Segment

Part of the ECG exam that, if elevated, suggests ischemia.

Abnormal Q Wave

Indicates potential infarction.

QT Interval

Length that, if more than half of RR interval, risks certain arrhythmias.

Tidal Volume (TV)

Volume of air moved in and out of the respiratory system during resting ventilation.

Inspiratory Reserve Volume (IRV)

Additional air that can be inhaled beyond resting inspiration.

Expiratory Reserve Volume (ERV)

Additional air that can be exhaled beyond normal expiration.

Vital Capacity (VC)

Greatest volume of air that can be moved with a single breath.

Residual Volume (RV)

Volume of air remaining in the respiratory system after complete expiration.

Total Lung Volume (TLV)

Max volume that can be in the respiratory system.

Inspiratory Capacity

Volume of air that can be inhaled after a normal resting expiration.

Functional Residual Capacity

Total volume left in the respiratory system after a normal expiration.

Chemoreceptors

Sensors that measure plasma O2, CO2, and pH levels.

Ventilation

Process that increases blood O2 saturation when low O2 is detected.

Cellular Metabolism

Increased metabolism leads to decreased blood pH and increased respiration.

Respiratory Alkalosis

Increased ventilation causes CO2 to be removed, resulting in increased pH.

Respiratory Acidosis

Decreased ventilation causes CO2 retention, resulting in decreased pH.

Metabolic Alkalosis

Increased pH due to metabolic issues, with decreased respiration to correct pH.

Metabolic Acidosis

Decreased pH due to metabolic issues, with increased respiration to correct pH.

Renal System

Responsible for homeostasis of blood pressure, plasma osmolarity, sodium, potassium, body water, and pH.

Renin

Enzyme produced by the kidney that initiates angiotensin II production.

Angiotensin II

Produced in the blood when renin is present; constricts blood vessels and increases blood pressure.

Aldosterone

Hormone secreted from the adrenal cortex that helps regulate sodium and potassium balance.

ADH (Antidiuretic Hormone)

Secreted by the pituitary gland, regulates water retention in response to osmolarity or blood pressure.

Hyperaldosteronism

Condition of high aldosterone leading to sodium retention and potassium loss.

Hypoaldosteronism

Condition of low aldosterone leading to potassium retention and sodium loss.

Digestive Enzymes

Hydrolytic enzymes that break down organic food molecules.

Hydrolysis

Chemical breakdown due to reaction with water, essential for digestion.

Cellulose

Fiber that cannot be hydrolyzed by digestive enzymes but can be fermented by bacteria.

Amylase

Enzyme produced in salivary glands and pancreas that breaks down starches.

Pepsin

Enzyme produced in the stomach that digests proteins under acidic conditions.

Trypsin

Pancreatic enzyme that breaks down proteins in the small intestine.

Chymotrypsin

Pancreatic enzyme that assists in protein digestion.

Lipase

Enzyme that hydrolyzes fats after they are emulsified by bile.

Bile

Substance that emulsifies fats making them easier for digestion by enzymes.

Hydrolases

Enzymes that catalyze the hydrolysis of chemical bonds in food.

Monosaccharides

Simplest form of carbohydrates including glucose, fructose, and galactose.

Digestive Tract

Pathway through which food passes and gets digested and absorbed.

Nutrient Absorption

Process by which digested food molecules are taken up into the bloodstream.

Acidic Conditions

Environment in the stomach that is necessary for pepsin activity.

Emulsification

Process of breaking down fats into smaller droplets to aid digestion.

Protein Hydrolysis

Chemical breakdown of proteins into smaller fragments or amino acids.

Gastrointestinal Tract

The organ system responsible for digestion and absorption.

Carbohydrate Digestion

Process of breaking down carbohydrates into sugars for absorption.

Fat Digestion

Process involving emulsification and hydrolysis of fats.

Protein Digestion

Breakdown of proteins into smaller peptides or amino acids.

Absorption Efficiency

Measure of how effectively nutrients are taken up by the body during digestion.

Dipeptidase

Enzyme in the small intestine that breaks down dipeptides into amino acids.

Aminopeptidase

Enzyme that breaks down amino acids from the start of peptide chains.

Sucrase

Enzyme that hydrolyzes sucrose into glucose and fructose.

Lactase

Enzyme that breaks down lactose into glucose and galactose.

Maltase

Enzyme that hydrolyzes maltose into two glucose molecules.

Volumetric Changes

Changes in volume of blood or gases in the lungs during physiological functions.

Fluid Balance

Homeostasis of fluids in the body essential for health.

Electrolyte Balance

Maintaining the correct levels of essential ions in the body.