Human Systems Physiology Exam Prep PDF

Podcast Title: Human Systems Physiology Exam Prep Host: Welcome to Human Systems Physiology Exam Prep! Today, we’re reviewing key concepts from Units 1 through 4 to get you ready for your final exam. Let’s dive in! Segment 1: Unit 1 – Basics of Physiology Host: First, let’s talk about osmolarity...

Podcast Title: Human Systems Physiology Exam Prep Host: Welcome to Human Systems Physiology Exam Prep! Today, we’re reviewing key concepts from Units 1 through 4 to get you ready for your final exam. Let’s dive in! Segment 1: Unit 1 – Basics of Physiology Host: First, let’s talk about osmolarity and tonicity of common solutions. Normal saline, or NS, is isotonic, while 1/2NS is hypotonic. D5 is 5% dextrose in water and acts as hypotonic after the glucose is metabolized. D5NS and D5 1/2NS start isotonic but become hypotonic as glucose is used. Next, let’s review membrane transport mechanisms. Passive transport like diffusion and facilitated diffusion doesn’t require energy, while active transport, like the sodium-potassium pump, does. Secondary active transport uses the gradient created by primary active transport to move substances like glucose into cells. When it comes to the reflex pathway of hormone release, remember this pattern: afferent signals detect a stimulus, the integrating center processes it, and efferent signals trigger a response. Finally, we’ll cover the hypothalamus-anterior pituitary hormones. The hypothalamus releases hormones like CRH, TRH, and GnRH, which prompt the anterior pituitary to release hormones like ACTH, TSH, and LH/FSH. Segment 2: Unit 2 – Nervous System and Communication Host: Time to switch gears to the nervous system! Graded potentials are short-distance signals that diminish over time, while action potentials are all-or-none and travel long distances. For brain areas and functions, remember: the frontal lobe handles decision-making, the parietal lobe processes sensory input, the occipital lobe is for vision, and the temporal lobe manages hearing and memory. Let’s not forget lateral inhibition, which sharpens sensory input by inhibiting adjacent neurons. Rods and cones—rods are for low light and peripheral vision, while cones handle color and high acuity. The dark current of rods keeps sodium channels open in the dark, depolarizing the cell. Finally, the autonomic nervous system includes sympathetic ("fight or flight") and parasympathetic ("rest and digest") divisions. Sympathetic uses norepinephrine at adrenergic receptors, while parasympathetic uses acetylcholine at muscarinic receptors. Segment 3: Unit 3 – Cardiovascular Physiology Host: Let’s now tackle cardiovascular physiology. The pacemaker cells in the SA node generate rhythmic action potentials, which spread through the heart. Their action potential relies on If channels, which allow slow sodium influx, depolarizing the cell. Stroke volume and cardiac output depend on preload, afterload, and contractility. Understanding the ECG is crucial: the P wave represents atrial depolarization, the QRS complex is ventricular depolarization, and the T wave is ventricular repolarization. For the pressure-volume curve, events include ventricular filling, isovolumetric contraction, ejection, and isovolumetric relaxation. Lastly, the baroreflex helps regulate blood pressure via sensors in the carotid arteries and aorta, triggering responses from the ANS. Segment 4: Unit 4 – Respiratory and Renal Physiology Host: Onto the last unit: respiratory and renal systems. For respiratory pathologies, COPD is a major one, causing airflow limitation and difficulty breathing. CO2 transport happens mostly as bicarbonate in the plasma, facilitated by carbonic anhydrase. In the renal system, GFR autoregulation maintains stable filtration through the myogenic mechanism and tubuloglomerular feedback. For the RAS pathway, renin converts angiotensinogen to ANGII, which raises blood pressure and stimulates aldosterone release. ADH increases water reabsorption, aldosterone promotes sodium retention, and ANP counteracts them by promoting sodium excretion. Severe dehydration triggers responses like ADH release to retain water and vasoconstriction to maintain blood pressure. Finally, pH balance relies on buffer systems, respiratory adjustments, and renal regulation. Closing Remarks Host: That’s a wrap! We’ve covered Units 1 through 4, touching on key topics from osmolarity to pH balance. Keep practicing, and good luck on your exam! You’ve got this.