Respiratory & Renal Physiology – Test #4 Review

Question–answer flashcards covering key concepts in Chapters 22 & 25: respiratory anatomy & physiology, gas transport, control of breathing, pathologies, kidney structure, nephron function, filtration, reabsorption, secretion, hormonal regulation, and counter-current mechanisms.

What are the eight primary functions of the respiratory system?

Gas exchange, humidification, warming incoming air, filtering pathogens, assisting venous & lymph return, sound production, olfaction, and pH balance (plus Valsalva maneuver )

List the respiratory passageway structures from nose to alveoli.

Nose/mouth → pharynx → larynx → trachea → right & left primary bronchi → secondary/tertiary bronchi → bronchioles → alveoli.

Which epithelium lines the nasal cavity and nasopharynx?

Pseudostratified ciliated columnar epithelium.

Which epithelium lines the oropharynx and laryngopharynx?

Non-keratinized stratified squamous epithelium.

What cartilage forms the epiglottis and what is its role?

Elastic cartilage; covers the laryngeal inlet during swallowing.

Describe the Valsalva maneuver.

Closing the glottis while contracting abdominal muscles to raise intra-abdominal pressure for defecation, childbirth, lifting, coughing, sneezing, singing.

Length, location, and tissue layers of the trachea.

~4 in long; extends from larynx to mediastinum, anterior to esophagus; mucosa of pseudostratified columnar epithelium, submucosa CT with seromucous glands & 16–20 C-shaped hyaline cartilage rings, outer CT adventitia.

Do bronchioles have cartilage? Do they have muscle?

No cartilage C-rings; walls contain smooth muscle and elastic fibers.

What does smoking do to the respiratory mucosa?

Destroys cilia and makes it so mucus can only be expelled via coughing

What is the Heimlich maneuver used for?

Clears trachea when blocked by foreign object

Name the two main alveolar cell types and their functions.

Type I: thin simple squamous cells for gas exchange; Type II: cuboidal cells secreting surfactant and antimicrobial proteins.

What does surfactant do in the alveoli?

Reduces surface tension of alveolar fluid, preventing collapse and improving gas exchange.

Which three cell types are found inside alveoli?

Type I cells, Type II cells, and alveolar macrophages.

How many lobes are in the right and left lungs?

Right lung – 3 lobes (superior, middle, inferior); Left lung – 2 lobes (superior, inferior) plus cardiac notch.

Define intrapulmonary pressure (Ppul).

Pressure within the alveoli; fluctuates with breathing and equalizes with atmospheric pressure between breaths

Define intrapleural pressure (Pip).

Pressure within the pleural cavity; normally ~4 mm Hg less than Ppul, keeping lungs inflated.

What is transpulmonary pressure and why is it important?

Ppul – Pip; keeps lung spaces open; higher transpulmonary pressure expands lungs.

State Boyle’s law in the context of breathing.

Pressure of a gas varies inversely with its volume

What is the clinical term for a collapsed lung?

Pneumothorax

What could cause a pneumothorax?

Any condition that equalizes Pip with Ppul; puncture wounds, ruptured visceral pleura

What is asthma?

Histamine release causes parasympathetic response that constricts bronchioles, Epi can trigger bronchi dilation

Which primary muscles drive quiet inspiration?

Diaphragm and external intercostal muscles.

Which muscles assist forced inspiration?

Scalenes, sternocleidomastoids, and erector spinae.

Which muscles assist quiet expiration?

Diaphragm and external intercostal relaxation

Which muscles are active during forced expiration?

Internal intercostals and abdominal muscles (obliques, transversus abdominis).

What is ventilation?

Amount of gas reaching alveoli

What is perfusion?

Amount of blood flow reaching alveoli

What causes optimal gas exchange in ventilation-perfusion coupling?

When ventilation and perfusion rates are matched

Describe ventilation-perfusion coupling when ventilation < perfusion.

Pulmonary arterioles constrict and bronchioles dilate to redirect airflow toward better-ventilated alveoli.

State Dalton’s law.

Total pressure of a gas mixture equals the sum of the partial pressures of each component gas.

State Henry’s law.

The amount of gas that dissolves in a liquid is proportional to its partial pressure and solubility

List three main factors influencing external respiration efficiency.

Thickness & surface area of respiratory membrane, partial pressure gradients & gas solubilities, and ventilation-perfusion matching.

What is the oxygen-hemoglobin dissociation curve?

Graph depicting how as Po2 increases, % of O2 saturation in Hemoglobin rises

What does the acronym TACOBAR stand for in reference to the oxygen-hemoglobin dissociation curve

Temp increase, Acidity increase, CO(2), BPG increase, Activity increase all cause Right curve shift indicating decreased affinity for O2

Percentage of O₂ transported by hemoglobin vs plasma.

About 98.5 % bound to hemoglobin; ~1.5 % dissolved in plasma.

Three main ways CO₂ is transported in blood.

7–10 % dissolved in plasma, ~20 % bound to hemoglobin as carbaminohemoglobin, ~70 % converted to bicarbonate ions using carbonic anhydrase, 1-3% slowly converted to bicarbonate in plasma

What happens to the remaining H+ ion during the carbonic anhydrase-catalyzed reaction in RBCs.

Bound to hemoglobin that gave up O2

What happens to the leftover H+ ion during bicarbonate reaction in plasma?

Binds to plasma proteins

Write the carbonic anhydrase-catalyzed reaction in RBCs.

CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻.

Location & function of the Ventral Respiratory Group (VRG).

Medulla oblongata; primary rhythm generator sending impulses via phrenic and intercostal nerves for breathing.

Location & function of the Pontine Respiratory Centers.

Pons; smooth the transition between inspiration & expiration

Location & function of the Dorsal Respiratory Group.

Integrates peripheral sensory input and modifies VRG breathing rhythm

Primary chemical factor driving increased ventilation.

Elevated arterial/brain CO₂ (hypercapnia) → lowered CSF pH → stimulates central chemoreceptors.

Define COPD and its two major forms.

Chronic Obstructive Pulmonary Disease: emphysema (alveolar destruction) and chronic bronchitis (excess mucus & airway inflammation).

Describe asthma pathophysiology and treatment.

Allergic inflammation releases histamine → bronchoconstriction; reversible with bronchodilators (epinephrine) and anti-inflammatory drugs.

What is the usual pH of the respiratory system and how does H+ concentration correspond?

7.35-7.45, H+ concentration is 10^-7 at pH 7

How does high altitude affect respiration?

High altitude decreases oxygen availability, leading to increased respiratory rate and depth to compensate for lower oxygen levels in the atmosphere

What is altitude sickness and what are its symptoms?

Quick travel to above 8000ft can cause headaches, nausea, SOB, dizziness, and severe cases cause cerebral/pulmonary edema due to low atm pressure

What is the cause and the symptoms of TB?

Caused by bacteria M. tuberculosis; symptoms include racking cough, fever, night sweats, weight loss, coughing up blood

What is lung cancer?

Cancer usually caused by smoking, detected with CT, chest Xray, or breath test; treated with surgical removal or chemo/radiation

What is CF?

Genetic condition where abnormally viscous mucus clogs passages in the lungs, pancreas, and reproductive ducts; caused by abnormal gene for Cl- membrane channels

Major functions of the kidneys (name at least five).

Regulate water volume & osmolarity, regulate ion balance, long-term acid-base balance, excrete wastes/toxins/drugs, produce renin & erythropoietin, activate vitamin D, perform gluconeogenesis during fasting.

Where is the kidney located?

Superior lumbar region between T12 to L5; R side crowded by liver and lower than L; adrenal gland on top of each

What are the 3 supportive layers and their composition of the kidneys?

Renal fascia, dense fibrous CT, perirenal fat capsule, adipose tissue, fibrous capsule (dense fibrous CT)

Describe the renal cortex

Superficial granular appearing region

Describe the renal medulla

cone shaped medullary pyramids separated by renal columns

What are the papilla?

Tips of renal pyramids that release urine into the minor calyx

What is a renal lobe?

Medullary tissue surrounding cortical tissue; about 8 per kidney

What is the renal pelvis?

Funnel shaped tube continuous with ureters and collects urine from major calyces

What is a minor calyces?

Drain pyramids of urine at papillae

What do the major calyces do?

collect urine from minor calyces and channel it to the renal pelvis

Trace the urine flow from renal pyramid to ureter.

Renal pyramid (papilla) → minor calyx → major calyx → renal pelvis → ureter

List the blood vessels in order from aorta to IVC through the kidney.

Aorta → renal artery → afferent arteriole → glomerulus → efferent arteriole → vasa recta/peritubular capillaries → renal vein → inferior vena cava.

Name the two major parts of a nephron.

Renal corpuscle and renal tubule.

What is the composition and function of the PCT?

Cuboidal cells with dense microvili and large mitochondria; reabsorbs water, ions, and nutrients from filtrate

What is the composition and function of the Nephron loop?

consists of descending and ascending limbs, is made up of simple squamous epithelium and cuboidal/columnar cells. concentrates urine by facilitating the reabsorption of water and sodium.

What is the composition and function of the DCT?

Cuboidal cells with few microvili; reabsorbs sodium, chloride, and water in cortex

What are the 2 cell types of collection ducts?

Principal cells; sparse short microvili, maintain h2o and Na balance and intercalated cells; cuboidal cells lots of microvili, A & B cells help maintain blood acid-base balance

Where are macula densa cells located and what do they sense?

Ascending limb of nephron loop; act as chemoreceptors for NaCl concentration in filtrate.

What hormone do granular (JG) cells release and why?

Enlarged smooth muscle cells; have Renin, released in response to low blood pressure in the afferent arteriole.

Define glomerular filtration.

Passive process where hydrostatic pressure forces water and small solutes through the filtration membrane to form protein-free filtrate

List the three layers of the filtration membrane.

Fenestrated endothelium of glomerular capillaries, fused basement membrane, and podocyte foot processes

Give normal values for HPgc, HPcs, and OPgc.

HPgc ≈ 55 mm Hg; HPcs ≈ 15 mm Hg; OPgc ≈ 30 mm Hg.

Write the net filtration pressure (NFP) equation.

NFP = HPgc − (HPcs + OPgc).

Name four substances reabsorbed in the PCT.

Glucose, amino acids, Na⁺, and water (plus vitamins, Cl⁻, HCO₃⁻, etc.).

What is tubular secretion and list two secreted ions.

Movement of substances from blood to filtrate; H⁺, K⁺, NH₄⁺, drugs are secreted

How does ADH affect urine formation?

Increases water permeability of collecting duct principal cells, promoting water reabsorption and producing concentrated urine.

How does aldosterone affect the nephron?

Stimulates Na⁺ reabsorption and K⁺ secretion in DCT and collecting ducts, indirectly increasing water reabsorption and blood volume.

Explain the counter-current multiplier in the nephron loop.

Descending limb loses water, concentrating filtrate; ascending limb pumps out NaCl, increasing medullary osmolality, creating an osmotic gradient for water reabsorption.

Role of the vasa recta in counter-current exchange.

Preserves medullary osmotic gradient by removing reabsorbed water and NaCl without dissipating the gradient.

If pH = 3, what is the H⁺ concentration?

[H⁺] = 10⁻³ M.

How does the body respond to low blood pH (acidosis)?

Peripheral & central chemoreceptors stimulate increased ventilation to blow off CO₂, reducing H⁺ ions and raising pH.

What substances are impermeable to the filtration membrane?

Blood cells and plasma proteins (e.g., albumin).

Which limb of the nephron loop is water-permeable?

Descending limb.

Which limb actively pumps Na⁺/K⁺/Cl⁻ into the medulla?

Thick ascending limb.

What effect does sympathetic stimulation have on the afferent arteriole?

Constriction, reducing GFR and conserving blood volume during stress.

Name two hormones that increase water reabsorption.

Antidiuretic hormone (ADH) and aldosterone (indirectly by Na⁺ reabsorption).

How does dehydration affect urine osmolarity?

Elevates ADH release, producing small volume of highly concentrated urine (up to 1200 mOsm).

What is the typical daily glomerular filtration volume?

Approximately 180 L/day.