Integrated Physiology Exam 4

These flashcards cover the key concepts related to the respiratory and renal systems, including definitions of terms, processes involved in gas exchange, kidney functions, hormone roles, and homeostatic mechanisms.

Respiratory system major function

Supplies body with O2 and removes CO2

Conducting Zones

Prepares air

Conducting zone branches

Trachea, primary and smaller bronchi, and bronchioles

Respiratory Zones

Where gas exchange takes place

Respiratory zone branches

Respiratory bronchioles, alveolar ducts, and alveolar sacs

Alveoli sacs

Terminal sacs of the lung where gas exchange takes place (?)

Type I Alveolar Cells

Main site of gas exchange

Type II Alveolar Cells

Secrete surfactant, reducing surface tension and helping to keep alveoli open

Pleura

Double-layer membrane covering the lungs

Pleural cavity

Facilitates expansion and contraction of the lungs

What is ventilation dependent on?

Atmospheric pressure, alveolar pressure, and intrapleural pressure

Three Phases of Breathing Cycle

The three phases are inhalation, exhalation, and rest, and they relate to Boyle’s law, which states that pressure and volume are inversely related.

Tidal Volume

The amount of air inhaled or exhaled during normal breathing.

Oxygen and Carbon Dioxide Exchange

Occurs via passive diffusion, governed by the behavior of gasses, explained by two laws (Dalton’s law and Fick’s law)

Dalton’s law

Each gas in a mixture of gases exerts its own pressure which is partial pressure, atmospheric pressure is the sum of all partial pressures

Oxygen transport

Oxygen has poor solubility, 98.5% is transported on hemoglobin in bed blood cells, the rest goes into plasma

Factors affecting oxygen affinity to hemoglobin

Acidity (pH), partial pressure of carbon dioxide, temperature, biphosphoglycerate (BPG)

Carbon dioxide transport

Is transported through the blood in three forms, dissolved in plasma, carbamino compounds, bicarbonate ions

Functions of the Kidney

Regulate extracellular fluid volume, blood pressure, osmolarity, pH, maintains ion balance, excrete wastes, produces hormones

Nephron

The functional unit of the kidney, responsible for filtering blood and forming urine.

Renal Corpuscle

Contains the filtration membrane of a nephron

Glomerular Filtration

Occurs at the renal corpuscle, fluid and solutes are filtered from the blood into the nephron.

Reabsorption

The process of reclaiming water and solutes from the filtrate back into the blood

Secretion

The process of transferring substances from the blood into the nephron for elimination

Excretion

The process of eliminating waste from the body in the form of urine

Glomerular Filtration Rate (GFR)

The rate at which blood is filtered in the kidneys, amount of filtrate formed per minute

Glomerular Filtration Rate (GFR) regulation

Regulated in different ways, autoregulation, neural regulation, hormonal regulation

Tubuloglomerular Feedback

A mechanism by which changes in filtration rate influence the GFR by adjusting afferent arteriole resistance.

Urine Concentration

The events that take place in the nephron for urine concentration, primarily in the loop of Henle and collecting ducts.

Micturition

The storage of urine and the micturition reflex

Micturition Reflex

The reflex that leads to the urination process, involving the contraction of the bladder and relaxation of the sphincters.

Body Fluid Compartments

Intracellular and extracellular compartments.

Does the body have more intracellular or extracellular fluid?

Intracellular, the body is 2/3 intracellular fluid

Water gain under normal conditions

Ingestion and metabolic synthesis

Water loss under normal conditions

Equal to the water gain, lost via urine, sweat, lung exhalation, and feces

Thirst Response

Physiological pathways that trigger the sensation of thirst to maintain fluid balance.

Four triggers of the thirst response pathways

Increased blood osmolarity, decreased blood volume, decreased blood pressure, dry mouth

Increased blood osmolarity (thirst response pathways)

Stimulates osmoreceptors in hypothalamus

Decreased blood volume (thirst response pathways)

Decreased activity of atrial volume receptors

Decreased blood pressure (thirst response pathways)

Decreased activity of baroreceptors in blood vessels or increased release of renin from kidneys (leads to increased angiotensin 2 formation)

All pathways stimulate this

Thirst center in hypothalamus, leads to increased thirst and water intake

Increased water intake

Decreases blood osmolarity, increases blood volume and blood pressure, and relieves dry mouth

Antidiuretic hormone (ADH)

Increases permeability of the collecting duct to water, and water is reabsorbed back into the bloodstream

Aldosterone

Allows for an increase in Na+ reabsorption, which then favors water reabsorption

Atrial Natriuretic Peptide (ANP)

Prevents reabsorption of sodium (Na+), in turn prevents excess reabsorption of water, leading to loss of more water in urine

Most abundant cation in extracellular fluid

Sodium

Most abundant anion in extracellular fluid

Chloride

Buffer Systems

Chemical systems in the blood that help maintain pH balance, including bicarbonate, phosphate, and protein buffers.

Most abundant buffer in the body

Protein buffer

Hypokalemia

Abnormally low levels of potassium in the blood, can lead to muscle weakness and failure of respiratory muscles and the heart

Hyperkalemia

Abnormally high levels of potassium in the blood, can lead to cardiac arrhythmias

Homeostatic Compensation for Dehydration

Processes the body initiates to compensate for severe dehydration, including ADH release and thirst stimulation.

Acidosis

When the blood pH drops below the normal range because of an excess H+, usually a blood pH below 7.35

Alkalosis

When the blood pH rises above the normal range because of a deficit in H+, usually a blood pH above 7.45