Case Studies in Human Physiology and Pathophysiology

What are the primary functions of the kidneys?

The kidneys filter blood, reabsorb essential substances, and secrete waste, regulating fluid balance, electrolytes, and acid-base homeostasis.

What hormones are released by the kidneys and their functions?

Erythropoietin (stimulates RBC production), Renin (regulates blood pressure), and Calcitriol (active vitamin D for calcium balance).

What is the diagnosis and compensation mechanism for metabolic acidosis?

Diagnosis: Low pH and low HCO₃⁻. Compensation: Increased breathing rate to lower PCO₂.

What are the immediate and long-term compensatory responses to metabolic acidosis?

Immediate: Respiratory compensation (hyperventilation). Long-term: Renal compensation (excreting H⁺ and reabsorbing HCO₃⁻).

What is hyperkalemia and its cause in renal failure?

Hyperkalemia is dangerously high potassium levels due to the failing kidney's inability to excrete K⁺.

What is hypernatremia and its cause in renal failure?

Hypernatremia is sodium retention due to impaired filtration in renal failure.

What is peripheral edema and its cause?

Peripheral edema is fluid accumulation due to disrupted osmotic balance.

What is the function of the Na⁺/K⁺ pump?

The Na⁺/K⁺ pump maintains resting membrane potential and is crucial for nerve and muscle function.

How does renal failure affect erythropoietin production?

Renal failure leads to erythropoietin deficiency, causing anemia due to low RBC production.

How is oxygen transported in the blood?

Oxygen binds to hemoglobin in red blood cells.

How is carbon dioxide transported in the blood?

CO₂ is transported as bicarbonate (HCO₃⁻), dissolved in plasma, or bound to hemoglobin.

What is the relationship between renal failure and blood pressure?

Hypertension is common in renal failure due to fluid retention and increased vascular resistance.

What role does the Renin-Angiotensin System play in blood pressure regulation?

The kidney regulates blood pressure via renin secretion.

What does the ECG P wave represent?

The P wave represents atrial depolarization.

What does the ECG QRS complex represent?

The QRS complex represents ventricular depolarization.

What does the ECG T wave represent?

The T wave represents ventricular repolarization.

What are the effects of hyperkalemia on the ECG?

Hyperkalemia can cause peaked T waves, widened QRS, and arrhythmias.

What is the function of autorhythmic cells in cardiac tissue?

Autorhythmic cells generate impulses in the heart.

What is the consequence of high potassium levels on cardiac action potentials?

High K⁺ disrupts depolarization, leading to abnormal rhythms.

What is Net Filtration Pressure (NFP) and its significance?

NFP is the balance of hydrostatic and osmotic pressure, crucial for fluid exchange in capillary beds.

What causes edema in the body?

Increased hydrostatic pressure leads to fluid leakage into tissues, causing edema.

What is the diagnosis and compensation mechanism for metabolic alkalosis in dehydration?

Diagnosis: High pH and elevated PaCO₂. Compensation: Respiratory system retains CO₂ (hypoventilation).

What are the mechanisms that correct hypotension due to fluid loss?

Baroreceptors detect low BP, activating the sympathetic nervous system and the Renin-Angiotensin-Aldosterone System (RAAS) to increase BP.

What is the effect of sympathetic activation on heart rate?

Increases heart rate via norepinephrine binding to β₁ receptors.

How does parasympathetic activation affect heart rate?

Decreases heart rate via acetylcholine binding to muscarinic receptors.

What happens to Net Filtration Pressure (NFP) and Glomerular Filtration Rate (GFR) when blood pressure is low?

Both NFP and GFR decrease.

What role does the afferent arteriole play in autoregulation of GFR?

Afferent arteriole dilation maintains GFR.

Describe the RAAS activation process in response to low blood pressure.

Renin release → Angiotensin II → Aldosterone → Sodium retention → Blood pressure increase.

What are the primary roles of sodium (Na⁺) in the body?

Maintains fluid balance, nerve impulses, and blood pressure.

What is the significance of potassium (K⁺) in physiological functions?

Essential for muscle contraction, nerve function, and cardiac rhythm.

How is oxygen (O₂) transported in the blood?

Binds to hemoglobin for transport.

What are the three monitored factors in pulmonary ventilation and breathing regulation?

CO₂ levels (PaCO₂), O₂ levels (PaO₂), and pH (acid-base balance).

What is hyponatremia and what causes it?

Hyponatremia is low sodium levels caused by excessive water intake without sufficient sodium replacement.

What are the effects of hyponatremia?

Confusion, weakness, and altered consciousness.

How can hyponatremia be corrected?

By administering IV fluids with sodium to restore balance.

What is the function of synapses in neuron communication?

Neurons communicate via synapses where neurotransmitters regulate mood and cognition.

What brain regions are involved in higher cognitive functions and memory processing?

Cerebral Cortex (higher cognitive functions) and Hippocampus (memory processing).

What is the role of the brainstem in autonomic functions?

Regulates autonomic functions like breathing and blood pressure.

What factors affect blood pressure?

Fluid volume, electrolytes, hormonal response (RAAS), and nervous system activation.

How do fats, carbohydrates, and proteins get digested and absorbed?

Fats are broken down by bile and pancreatic lipase; carbohydrates by amylase; proteins by pepsin and proteases.

What are the signs of inflammation?

Redness, swelling, warmth, and pain.

What triggers the inflammatory response?

Tissue damage triggers the release of histamine, increasing blood flow and capillary permeability.

What is the difference between non-specific and specific immune defenses?

Non-specific defenses are immediate and general (e.g., skin, inflammatory response), while specific defenses are targeted (e.g., B Cells produce antibodies, T Cells attack infected cells).

What is the function of capillary beds in the immune response?

Exchange nutrients, oxygen, and immune cells.

What is the primary function of capillary beds?

Exchange nutrients, oxygen, and immune cells.

What mechanism pushes fluid out of capillary beds?

Hydrostatic Pressure.

What mechanism pulls fluid back into capillary beds?

Osmotic Pressure.

How does inflammation affect capillary permeability?

Increased permeability allows immune cells to reach the infection site.

What condition does Maria's case highlight?

Type 2 diabetes and its impact on fluid balance and kidney function.

What are the three types of hormones?

Peptide hormones (e.g., insulin), steroid hormones (e.g., cortisol), and amine hormones (e.g., epinephrine).

How do target cells recognize hormones?

Target cells have specific receptors that bind hormones, triggering a response.

What regulates hormone release?

Negative feedback loops.

What is the function of insulin?

Lowers blood glucose by promoting uptake into cells.

What is the function of glucagon?

Raises blood glucose by stimulating glycogen breakdown.

What is somatostatin's role in the pancreas?

Regulates insulin and glucagon secretion.

What are common symptoms of insulin deficiency?

Increased thirst and urination, weight loss, fatigue, and blurry vision.

What triggers the thirst reflex?

Osmoreceptors in the hypothalamus when blood osmolarity rises.

How do kidneys regulate fluid balance?

Through filtration, reabsorption, and secretion.

What occurs during filtration in the urinary system?

Waste is removed from blood in the glomerulus.

What is reabsorption in the nephron?

Reclaiming essential nutrients like glucose and Na⁺.

What happens to glucose in diabetes regarding reabsorption?

Excess glucose exceeds transport capacity, leading to glucosuria.

What is the formula for Glomerular Filtration Rate (GFR)?

GFR = (Urine concentration × Urine flow rate) ÷ Plasma concentration.

What regulates GFR?

Autoregulation, RAAS activation, and sympathetic nervous system response.

What respiratory condition is highlighted in Maggie's case?

Respiratory distress likely due to bronchitis or another respiratory infection.

What are the major organs of the respiratory system?

Nose, pharynx, larynx, trachea, bronchi, and lungs.

What is Forced Vital Capacity (FVC)?

Total air exhaled forcefully.

What does the FEV₁/FVC ratio indicate?

Indicates obstruction; a low ratio suggests airway narrowing.

What is the effect of albuterol on the respiratory system?

It is a beta-2 agonist that relaxes bronchial muscles, improving airflow.

What is pulmonary ventilation?

Air movement in and out of the lungs.

What is external respiration?

Gas exchange between alveoli and blood.

What is internal respiration?

Gas exchange between blood and tissues.

What does Fick's Law state about gas exchange?

Gas exchange depends on surface area, membrane thickness, and pressure gradient.

How does inflammation affect oxygen diffusion in the lungs?

Inflammation thickens alveolar membranes, reducing oxygen diffusion.

How is oxygen transported in the blood?

Oxygen binds to hemoglobin in red blood cells (RBCs).

What are the three ways carbon dioxide is transported in the blood?

As bicarbonate (HCO₃⁻), dissolved in plasma, or bound to hemoglobin.

What does an SpO₂ level of 88% indicate?

It indicates low oxygen binding to hemoglobin.

How can infections and fever affect the oxygen saturation curve?

Infections and fever can shift the curve, affecting oxygen delivery.

What is the difference between ventilation and perfusion?

Ventilation is the air reaching the alveoli, while perfusion is the blood flow to the alveoli.

How does inflammation impact ventilation and oxygenation?

Inflammation can reduce ventilation, impairing oxygenation.

What role does fever play in the immune response?

Fever increases metabolic rate and enhances the immune response.

What are the functions of B cells and T cells in the immune system?

B cells produce antibodies, while T cells attack infected cells.

What triggers the activation of B and T cells?

Activation is triggered by antigen recognition.

Where are alpha and beta receptors located in the body?

Alpha receptors are found in blood vessels; beta receptors are found in the lungs (β₂) and heart (β₁).

What effect does albuterol have on the respiratory system?

Beta-2 activation relaxes bronchial muscles, improving airflow.

What is acute myeloid leukemia (AML)?

A condition where abnormal white blood cells overcrowd the bone marrow, disrupting normal blood cell production.

What are the primary functions of red blood cells (RBCs), white blood cells (WBCs), and platelets?

RBCs carry oxygen, WBCs fight infections, and platelets help with blood clotting.

What is the structure of red blood cells?

RBCs have a biconcave shape, lack a nucleus, and transport oxygen.

What regulates breathing rate in the body?

The medulla oblongata and pons regulate breathing rate.

What factors are monitored to control breathing?

CO₂ levels (PaCO₂), O₂ levels (PaO₂), and pH (acid-base balance).

What is erythropoietin (EPO) and its role?

EPO is produced by the kidneys and stimulates RBC production in the bone marrow.

How does AML affect red blood cell production?

Bone marrow dysfunction reduces RBC production, causing anemia and fatigue.

What are the three steps of hemostasis?

1. Vascular spasm: Blood vessel constriction. 2. Platelet plug formation: Platelets adhere to the injury site. 3. Coagulation: Clotting cascade stabilizes the clot.

What symptoms are associated with anemia and their physiological causes?

Fatigue and pallor due to low RBC count; frequent infections due to abnormal WBCs; bruising and slow healing due to low platelet count.

How does blood viscosity affect blood pressure?

High WBC count thickens blood, increasing resistance and affecting blood pressure.

What are the short-term and long-term mechanisms for blood pressure regulation?

Short-term: Baroreceptors adjust heart rate and vessel diameter. Long-term: RAAS system regulates fluid balance and blood pressure.

What does left ventricular hypertrophy suggest?

Chronic pressure overload.

What does a prolonged PR interval indicate?

Delayed atrioventricular conduction.

What do non-specific T wave abnormalities reflect?

May reflect ischemia or electrolyte imbalances.

Which ions regulate cardiac cell membrane potentials?

Na⁺, K⁺, and Ca²⁺.

What are the phases of the cardiac cycle?

Diastole (ventricular filling) and Systole (ventricular contraction).