Comprehensive Exam Prep Notes: Theoretical Framework, Tissues, Diagnostics, and Key Concepts

Theoretical framework for studying this material

  • The class follows a four-step framework to connect concepts: speak the language first, assess structure and function when things are working, then examine what happens when things aren’t working (disease/medical conditions), and finally discuss procedures and pharmacology to correct issues.
  • Step 1: Speak the language (Greek/Latin roots, terminology).
  • Step 2: Look at things when structurally sound and functioning perfectly.
  • Step 3: Consider what happens when things are not working perfectly (medical condition, disease, possibly death).
  • Step 4: Explore procedures to correct and pharmacology (drugs and drug interactions).
  • This framework links to pharmacology, microbiology, chemistry, and biochemistry, showing how multiple disciplines integrate in physiology.
  • The focus of exams and review sheets will reflect what is discussed in lectures, so active engagement with the language and terminology is essential.

Language, roots, and key terminology

  • Extracorporeal is introduced as a useful word; emphasize the importance of Greek/Latin roots going forward.
  • Major suffix/prefix cues:
    • endo- = in, inside; exo- = out, external
    • -crine (from Greek crino) = to secrete
    • -osis, -otic indicate a condition involving a process (e.g., thrombosis: clot formation)
    • -logy = the study of
  • Important example: endocrine vs exocrine
    • Endocrine = secretion into the bloodstream (hormones)
    • Exocrine = secretion onto surfaces or ducts (outside the body or into a lumen)
    • There can be overlap in some contexts (e.g., GI tract secretions that ultimately interact with the lumen), but the core idea is secretions into blood vs onto surfaces.
  • Language demands: you must be able to interpret terms and connect to physiology (e.g., endocrine, exocrine, crine, hema/hemo-, cyto-, and the various organ-system terms).
  • Acronyms to watch for: RNP = resting membrane potential; AP = action potential; CAC = coronary artery calcium score; CT = computed tomography; MRIs, echocardiogram, nuclear stress test, PET scan, etc.

Tissues and basic tissue properties

  • Tissue definition: a group of cells and/or fluids designed to perform a specific function.
  • Four primary tissue types:
    • Epithelial
    • Connective
    • Muscle
    • Nervous
  • Key functional distinction:
    • Epithelial and connective tissues are non-excitable (do not generate action potentials).
    • Muscle and nervous tissues are excitable and can generate action potentials using a resting membrane potential (RNP).
  • Resting membrane potential (RNP): the voltage difference across the cell membrane when at rest; inside is typically negative relative to the outside.
  • For scaffolding in exam prep: understand tissues, the language to describe them, and how RNP and action potentials differ between excitable and non-excitable tissues.
  • Example of anatomical organization: organs are composed of multiple tissues working together to perform a specific function.

Cells, energy, and metabolic context

  • Red blood cells (RBCs) specifics:
    • RBCs lack nuclei and mitochondria; thus they cannot perform oxidative phosphorylation.
    • ATP production in RBCs relies on glycolysis from glucose, yielding net ATP.
    • Glycolysis steps and ATP accounting as described in student narrative:
    • Step 1: Glucose → Glucose-6-phosphate via hexokinase; consumes ATP.
      • Glucose+ATP→Glucose-6-phosphate+ADP\text{Glucose} + \text{ATP} \rightarrow \text{Glucose-6-phosphate} + \text{ADP}
    • Step 3: Fructose-6-phosphate → Fructose-1,6-bisphosphate via phosphofructokinase; consumes ATP.
      • Fructose-6-phosphate+ATP→Fructose-1,6-bisphosphate+ADP\text{Fructose-6-phosphate} + \text{ATP} \rightarrow \text{Fructose-1,6-bisphosphate} + \text{ADP}
    • Overall glycolysis yields four ATP, but two ATP are consumed in the above steps, giving a net production of two ATP per glucose.
      • Net ATP from glycolysis: 4−2=24 - 2 = 2
  • Implication: because RBCs have no mitochondria, they rely on glycolysis for ATP to support cell viability and function.
  • Brain energy and oxygen use:
    • The brain uses roughly 20–30% of the body’s oxygen and glucose due to high metabolic demand.
  • Other energy-related notes:
    • Mitosis supports growth and repair; the human body has on the order of ~20–40 trillion cells and loses billions of cells daily.
    • Dysregulated mitosis can lead to cancer; fever is a defense but excessive or uncontrolled responses can be harmful.
    • Dehydration and electrolyte imbalances can result from vomiting/diarrhea when defenses go awry.
  • Key physiological principle: normal processes and defenses are fine in the short term, but can be detrimental if dysregulated or sustained long term.
  • Hypoglycemia: low blood glucose can impair brain function, RBCs, and liver function due to their dependence on glucose.

Hormones, feedback, and metabolic regulation

  • Hormonal regulation of blood glucose involves five terms (four hormones, plus a naming note):
    • Adrenaline (epinephrine) = same hormone, different names from two origins (adrenaline = Latin; epinephrine = Greek); both mean "upon the kidney" (location of adrenal glands).
    • Cortisol: stress hormone from adrenal cortex; role in metabolic regulation and stress response.
    • Glucagon: from alpha cells in the pancreas; raises blood glucose.
    • Growth hormone: from anterior pituitary; raises blood glucose and has anabolic effects somewhat complex in energy balance.
    • Erythropoietin (EPO): hormone produced by the kidneys that stimulates erythropoiesis in the red marrow.
  • The four primary hormones that elevate blood glucose (besides adrenaline) are: cortisol, glucagon, growth hormone, and adrenaline (epinephrine).
  • Sleep and stress interplay: chronic stress and sleep deprivation can elevate disease risk and influence immune function.
  • Hemodynamic regulation and autonomic control: sympathetic vs parasympathetic influences on blood flow, heart rate, and organ perfusion.
  • Important warning on narcotics: opiates as narcotics can significantly affect heart rate, respiration, and blood pressure; caution due to risk of adverse effects and dependence. Emphasis on responsible use and awareness of risks.

Vitamin K, coagulation, and liver health

  • Vitamin K origins and role:
    • Vitamin K name origin relates to Danish terms connected to clotting and coagulation; bacteria in the GI tract synthesize much of the vitamin.
    • Vitamin K is stored in the liver and functions as a cofactor in coagulation pathways.
  • Liver disease and coagulation:
    • Cirrhosis (scarred liver) is common in alcoholics and can impair vitamin K storage, leading to clotting impairments.
  • Practical takeaway: individuals with liver cirrhosis may have coagulation defects due to impaired vitamin K handling.
  • Broad context: humans host a large number of prokaryotic cells; the microbial population contributes to vitamin K synthesis, among many other roles.

Capillaries, fluid movement, and edema

  • Capillary beds are extremely thin (one endothelial cell layer thick) and are sites of exchange between blood and tissues.
  • Fluid dynamics across capillaries involve hydrostatic and oncotic forces (not all details enumerated here, but essential for edema understanding).
  • The lymphatic system collects and transports excess interstitial fluid (lymph) from capillary beds to prevent edema.
  • Edema is primarily caused by injury or pathology that increases capillary leakage or impairs lymphatic drainage.
  • A capillary bed’s function: leak fluid continuously; the lymphatic system reabsorbs or drains this fluid.

The integumentary system and skin basics

  • The integument (skin) is the largest organ.
  • Skin structure: five epidermal layers (top two layers are dead; third layer is moribund/dying).
  • Glands, nails, and hair: additional components of the integumentary system.
  • Important terminology: secreting vs excreting (Greek crino/krino)…
    • Secretion (secrete) implies a useful product kept/used by the body.
    • Excretion (excrete) implies removal/waste from the body.
  • Exemplar: liver/kidneys/skin/colon act as major excretory organs for waste products.

Skeletal system and marrow activity

  • Bone marrow cavities:
    • Red marrow: active, involved in hematopoiesis (production of blood cells).
    • Yellow marrow: fatty, inactive in hematopoiesis.
    • With aging, red marrow is progressively replaced by yellow marrow, reducing hematopoietic capacity.
  • Erythropoietin (EPO) is a kidney-derived hormone that stimulates red marrow to produce RBCs.
  • Skeleton and systemic context: bones, marrow, and associated hormones contribute to systemic homeostasis (e.g., RBC supply, mineral storage).

Skeletal muscle and metabolism

  • Skeletal muscle is the primary voluntary tissue with visible outward manifestations (e.g., movement, posture).
  • It is a major determinant of basal metabolic rate (BMR): more skeletal muscle mass elevates BMR.
  • The CNS and PNS drive motor control, reflexes, and cognition, but skeletal muscle is the only tissue with both voluntary control and visible manifestation under normal conditions.

The nervous system: CNS, PNS, and cognitive function

  • Central nervous system (CNS) = brain and spinal cord.
  • Peripheral nervous system (PNS) = all nerves outside CNS; includes 31 pairs of spinal nerves and 12 cranial nerves.
  • For exam preparation, know:
    • 31 pairs of spinal nerves
    • 12 pairs of cranial nerves
    • Foramen knowledge: nerves pass through specific foramina (refer to page 47 for the full list of foramina and their exit points).
  • Cognition: defined as the brain's ability to think, reason, and engage in cause-and-effect analysis; primarily localized to cortical areas, particularly the prefrontal cortex.
  • Brain energy: the brain relies heavily on glucose; it uses 20–30% of the body’s oxygen and glucose supply.

Endocrine vs exocrine, and key organ interactions

  • Endocrine secretions go into the bloodstream and act as hormones; exocrine secretions exit via ducts to surfaces or lumens.
  • Important examples of endocrine products include adrenaline (epinephrine), cortisol, glucagon, growth hormone, and erythropoietin; these hormones regulate metabolism, energy balance, and hematopoiesis.
  • Some contexts show potential overlap (e.g., GI tract secretions), but the canonical definitions remain useful for exam purposes.

Digestive and metabolic contexts: liver, pancreas, and biliary system

  • Pancreas and liver contribute to metabolism and digestion via endocrine and exocrine secretions.
  • The liver is central to vitamin storage (e.g., vitamin K) and detoxification; liver disease (cirrhosis) can impact multiple systems via reduced vitamin storage and altered coagulation.
  • The pancreas has endocrine components (alpha cells secrete glucagon) and exocrine components (ductal secretions for digestion).

Imaging and diagnostic modalities in cardiovascular assessment

  • CT (computed tomography) scans can provide tomographic imaging (note the distinction from topographic imagery and the importance of the term tomographic).
  • Coronary Artery Calcium (CAC) score:
    • Purpose: assess calcification in coronary arteries as a marker of atherosclerosis risk.
    • The example discussed yielded a CAC score of just over 400, prompting further investigation.
    • General principle: higher CAC scores correlate with greater risk; early detection is key.
  • Echocardiogram:
    • An ultrasound-based evaluation of heart structure and function.
  • Nuclear stress test:
    • Involves imaging the heart at rest and during exercise to assess perfusion and function; includes pharmacologic or treadmill-based stress tests.
    • Concept: adrenaline/epinephrine role in physiological responses during stress testing may be leveraged or discussed in clinical contexts.
  • Other imaging mentions:
    • Ultrasound for various organ systems (liver, kidneys, pancreas, vessels) and for blood flow assessment.
  • PET scans:
    • Early history referenced (Emory University as a pioneer); PET scans provide metabolic imaging.

Practical clinical anecdotes and connections

  • Anecdote: Tuesday as “beauty shop day” led to scheduling changes for clinical visits and imaging; emphasizes the impact of real-life scheduling on education and patient care.
  • Anecdote: a high CAC score led to a cascade of tests (echocardiogram, ultrasound of liver/kidneys/pancreas, nuclear stress test) to evaluate cardiovascular risk and perfusion.
  • Anecdote: vitamin K storage is impaired in cirrhosis typically seen in alcoholics, linking liver health with coagulation status; practical implication for patient management and risk assessment.
  • Broader clinical message: early detection and integrated care across organ systems improve outcomes; chains of cause/effect run across the liver, bone marrow, heart, and brain, illustrating system-wide connectivity.

Key numeric and factual references to remember

  • Blood glucose and energy:
    • Brain oxygen and glucose use: ~20–30% of body’s oxygen and glucose supply.
    • Glycolysis in RBCs yields a net of 2 ATP per glucose molecule (4 produced minus 2 consumed in early steps).
  • RBC biology:
    • RBCs lack nuclei and mitochondria; rely on glycolysis for ATP.
  • Abbreviations to remember:
    • RNP: resting membrane potential
    • AP: action potential
    • CAC: coronary artery calcium score
  • Vascular and fluid biology:
    • Capillary bed: a single endothelial cell layer; site of exchange and minor fluid leakage.
    • Lymphatic system drains interstitial fluid (lymph) from capillary beds.

Quick glossary and quick-reference ideas

  • Thrombosis: clot formation; if clots occlude vessels, tissue oxygenation and ATP can drop, potentially leading to tissue death.
  • Myocardial infarction: heart attack due to blockage of a coronary vessel.
  • Stroke: brain ischemia due to vessel occlusion.
  • Edema: swelling from excess fluid; can arise from capillary leakage or impaired lymphatic drainage.
  • Petechiae: small hemorrhagic spots; potential diagnostic sign in eye exams and other assessments.
  • Cognition: brain’s ability to think, reason, and understand cause-effect relationships; closely linked to prefrontal cortex function.

Connections to prior and future topics

  • Foundational links: tissues and organ systems set the stage for understanding anatomy, physiology, and pathophysiology.
  • Foundational chemistry/biochemistry: glycolysis, acid-base balance, and hormone signaling underpin clinical contexts discussed in later lectures.
  • Diagnostic imaging and clinical decision-making: sequences of tests (CAC → echocardiogram → ultrasound → nuclear stress test) illustrate how clinicians escalate evaluation based on initial findings.
  • Ethics and practical implications: stress management, sleep, and responsible management of narcotics are woven into clinical reasoning and patient care considerations.

Notes on exam strategy and study habits (embedded in framework)

  • Expect questions that map to the four-step theoretical framework: language, normal structure, disease, correction.
  • Be able to translate between terminology, diagrams, and real-world clinical examples.
  • Practice interpreting terms from roots (endo/exo, crine, osis/otic, hemo/hemo-, cyto-, cognition) and applying them to organ systems and processes.
  • Prepare for Roman numeral style questions by evaluating which items on a list are actually correct, using the language and known physiology rather than assuming every listed item is true.
  • Remember that physiology is cumulative: build from tissues, to organ systems, to integrated responses across the body.

Quick end-of-notes recap

  • Theoretical framework anchors learning: language first, normal structure, disease states, corrective pharmacology.
  • Tissues: four types; excitable (muscle, nervous) vs non-excitable (epithelial, connective); RNP and AP concepts.
  • Brain and energy: brain’s high energy demand; RBCs rely on glycolysis; glycolysis net yield = ${2}$ ATP per glucose.
  • Hormones and endocrine signaling: adrenaline, cortisol, glucagon, growth hormone, EPO; endocrine vs exocrine definitions.
  • Cardiovascular imaging and risk: CAC score as a risk marker; sequential imaging for risk stratification.
  • Fluid dynamics: capillary beds, hydrostatic/oncotic forces, lymphatics, edema.
  • Liver and vitamin K: health of liver; cirrhosis impact on coagulation via vitamin K storage.
  • Nervous system organization: CNS vs PNS; 31 spinal nerve pairs; 12 cranial nerves; cognition and frontal cortex.
  • Practical cautions: narcotics risks; stress management; the interconnectedness of body systems in physiology.