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BDS General Physiology Flashcards
56 question-and-answer cards covering General Physiology as it is examined in BDS. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the General Physiology deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
What generates the pacemaker (funny) current in SA node cells?
The slow inward $I_f$ current carried mainly by $\ce{Na+}$ (and some $\ce{K+}$) through HCN channels, causing spontaneous diastolic depolarization toward threshold.
State the fundamental hemodynamic equation relating flow, pressure, and resistance.
$$Q = \frac{\Delta P}{R}$$ where $Q$ is flow, $\Delta P$ is the pressure gradient, and $R$ is resistance (analogous to Ohm's law).
State Poiseuille's law and its most important implication for vascular resistance.
$$Q = \frac{\pi \Delta P r^{4}}{8 \eta L}$$ Flow is proportional to the fourth power of the radius, so small changes in vessel radius cause large changes in flow and resistance.
Define mean arterial pressure and give the estimating formula.
MAP is the average arterial pressure over one cardiac cycle: $$MAP \approx DBP + \frac{1}{3}(SBP - DBP)$$ or $MAP = CO \times TPR$.
Which blood vessels are the primary site of resistance and of gas/nutrient exchange?
Arterioles are the main resistance vessels (regulating blood pressure); capillaries are the site of exchange due to their thin walls and large total surface area.
Name the conducting and respiratory portions of the airway.
Conducting zone (no gas exchange): nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles. Respiratory zone (gas exchange): respiratory bronchioles, alveolar ducts, and alveoli.
What are pneumocytes type I and type II?
Type I pneumocytes are thin squamous cells forming the gas-exchange surface; type II pneumocytes secrete pulmonary surfactant and can regenerate the alveolar epithelium.
Explain how the diaphragm and intercostals produce quiet inspiration.
Contraction of the diaphragm (flattening downward) and external intercostals (raising the ribs) expands the thoracic cavity, lowering intrapleural and alveolar pressure below atmospheric so air flows in.
State Boyle's law and its relevance to breathing.
$$P_1 V_1 = P_2 V_2$$ At constant temperature, pressure varies inversely with volume; increasing thoracic volume lowers alveolar pressure to draw air in during inspiration.
What is pulmonary surfactant and why is it important?
A phospholipid–protein mixture (rich in dipalmitoylphosphatidylcholine) secreted by type II pneumocytes that reduces alveolar surface tension, preventing alveolar collapse and reducing the work of breathing.
Define tidal volume, vital capacity, and residual volume.
Tidal volume is air moved per normal breath (~500 mL); vital capacity is the maximum air expelled after maximal inspiration (IRV + TV + ERV); residual volume is air remaining after maximal expiration (cannot be exhaled).
State Fick's law of diffusion as it applies to alveolar gas exchange.
$$V_{gas} \propto \frac{A \cdot D \cdot (P_1 - P_2)}{T}$$ Diffusion rate is proportional to surface area $A$, the diffusion coefficient $D$, and partial pressure difference, and inversely proportional to membrane thickness $T$.
How is oxygen primarily transported in the blood?
About 98% is bound to hemoglobin as oxyhemoglobin ($\ce{Hb} + \ce{O2} \rightarrow \ce{HbO2}$); only about 2% is dissolved in plasma.
What is the Bohr effect?
An increase in $\ce{CO2}$ or $\ce{H+}$ (lower pH) shifts the oxygen–hemoglobin dissociation curve to the right, decreasing hemoglobin's affinity for $\ce{O2}$ and promoting $\ce{O2}$ unloading in active tissues.
In what forms is carbon dioxide transported in the blood, and which is dominant?
As bicarbonate ($\ce{HCO3-}$, ~70%, formed via $\ce{CO2 + H2O <=> H2CO3 <=> H+ + HCO3-}$), bound to hemoglobin as carbaminohemoglobin (~23%), and dissolved in plasma (~7%).
Which brainstem centers control the basic rhythm of breathing?
The medullary respiratory center (dorsal and ventral respiratory groups) sets the basic rhythm, modulated by the pontine centers (pneumotaxic and apneustic areas).
Which chemoreceptors most powerfully regulate ventilation and to what stimulus?
Central chemoreceptors in the medulla respond mainly to increased $\ce{CO2}$ (via increased $\ce{H+}$ in CSF); peripheral chemoreceptors (carotid and aortic bodies) respond to low $\ce{O2}$, high $\ce{CO2}$, and low pH.
Name the divisions of the nervous system anatomically and functionally.
Anatomically: central nervous system (brain and spinal cord) and peripheral nervous system (nerves/ganglia). Functionally the PNS divides into somatic (voluntary) and autonomic (sympathetic and parasympathetic) systems.
Compare the actions of the sympathetic and parasympathetic nervous systems.
Sympathetic (thoracolumbar) mediates 'fight or flight': increases heart rate, dilates pupils, dilates airways, inhibits digestion. Parasympathetic (craniosacral) mediates 'rest and digest': slows heart rate, constricts pupils, stimulates digestion.
Describe the sequence of events in chemical synaptic transmission.
An action potential opens voltage-gated $\ce{Ca^{2+}}$ channels at the presynaptic terminal; $\ce{Ca^{2+}}$ influx triggers vesicle fusion and neurotransmitter release; the transmitter binds postsynaptic receptors, altering membrane potential (EPSP or IPSP).
What is the difference between an EPSP and an IPSP?
An excitatory postsynaptic potential (EPSP) is a depolarization that brings the neuron toward threshold; an inhibitory postsynaptic potential (IPSP) is a hyperpolarization that moves it away from threshold.
Define a sensory receptor and list the main functional classes.
A structure that transduces a stimulus into electrical signals. Classes include mechanoreceptors (touch/pressure), thermoreceptors (temperature), photoreceptors (light), chemoreceptors (chemicals), and nociceptors (pain).
What is sensory transduction and receptor (generator) potential?
Transduction is conversion of a stimulus into a change in membrane potential; the resulting graded depolarization is the receptor or generator potential, which, if it reaches threshold, triggers action potentials in the afferent neuron.
Name the photoreceptors of the retina and their functional roles.
Rods provide high-sensitivity, monochromatic vision in dim light (scotopic); cones provide color vision and high acuity in bright light (photopic) and come in three types tuned to different wavelengths.
What this deck covers
The General Physiology deck follows the BDS General Physiology syllabus — 10 chapters and 43 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 5.6 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 194 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
General Physiology flashcards FAQ
How many General Physiology flashcards are in this BDS deck?
56 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these BDS flashcards free?
Yes. The preview here is free to read with no signup, and the full 56-card deck is free inside the Examius app.
What do the General Physiology cards cover?
They follow the BDS General Physiology syllabus — 10 chapters and 43 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.