Physiology - Exam 1

Introduction to Physiology

1. What differentiates science from non-science?

   1. Science is the mechanism for learning about natural phenomena through observation and experimentation. (theory, hypothesis) Non-science is any system of knowledge or thought that can not be addressed by the scientific method. (cultural norm, religion)

2. What does the acronym CONPTT mean in this context?

   1. Consistent, Observable, Natural, Predictive, Testable, Tentative

3. What is physiology?

   1. Study of how anatomical features provide function that cover many field

4. Positive Feedback Loop

   1. product of a reaction leads to an increase in reaction (lactation - child stimulates milk production which causes further production; giving birth)

5. Negative Feedback Loop

   1. reaction that causes a decrease in function (thermoregulation)

6. What is the comparative method in physiology?

   1. Comparing the similarities and differences among species to gain an understanding of evolutionary relationships

7. Can you give an example of a question that might be answered using the comparative method?

   1. Why do humans have wisdom teeth?

8. What were some of the major human health achievements from 1900-1999?

   1. healthier mothers and babies; vaccinations; control of infectious diseases

9. Understand the limitation of correlative data.

   1. it can determine association between exposure and outcomes but cannot predict causation

   2. Proximate Explaination

   3. How? mechanism (genetics, biochemistry) and development (environment)

   4. Ultimate explaination

   5. Why? function (adaptive value) and phylogeny (evolutionary constraint)

Physiology Basics

1. Lipids

   1. fats often made of triglycerides; includes steroids, phospholipids

2. Proteins

   1. made of C, H, O, and N; made of amino acids

3. Nucleic Acid

   1. made up of nucleiotides (5 C sugar, phosphate group, and nitrogenous base); form DNA and RNA

4. Carbohydrates

   1. made up of C, H, and O; monosaccharide has 1 sugar, disaccharide has 2 sugars, and a polysaccharide has many sugars

5. Understand the central dogma of molecular biology.

   1. DNA replication, transcription to RNA, translation to protein

6. Understand basic eukaryotic cell organization.

   1. cells makes up tissues, which makes up organs, which makes up organ systems

7. What is the most abundant cell type in the human body?

   1. red blood cells

8. What are the body compartments named in Fig 3.1?

   1. Body cavities: cranial, thoracic, abdominopelvic
   2. Body Fluid: Extracellular fluid (blood plasma, intersitial fluid), Cells (intracellular fluid)

9. Epithelial tissue

   1. forms barriers, linings, and glands; covers exposed surfaces; high rate of regeneration

   2. Muscle tissue

   3. special ability to shorten or contract in order to produce movement of the body parts, 3 types: smooth, cardiac, skeletal

   4. Nervous tissue

   5. highly specialized for electrical communication between cells of the body; comprises the brain, spinal cord, and nerves

   6. Connective tissue

   7. most abundant and diverse tissue; functions to support, anchor, and link other structures together; contains non-living “extracellular matrix”

   8. Bioenergetics

   9. study of energy flow through biological systems

   10. Metabolism

   11. all chemical reactions that occur within an organism

   12. Understand the reciprocity between autotrophs and heterotrophs

   13. Autotrophs are able to make their own food through photosynthesis while heterotrophs cannot make their own food and consume autotrophs

   14. Understand why enzymes are needed to catalyze reactions. Understand basic concepts for
       how enzymes function.

   15. Enzymes act as a catalyst to lower the activation energy needed for a reaction

   16. Exergonic

   17. catabolic, reaction where energy is released; breaking apart; A → B + C + energy

   18. Endergonic

   19. anabolic, reaction requiring energy; combining; A + B + energy → C

   20. Name four ways to regulate metabolism.

   21. control enzyme concentration; modulate enzyme activity; use different enzymes to catalyze reversible reactions; maintain optimum ADP/ATP ratio

   22. Understand the main steps of aerobic metabolism including where each takes place in the
       cell.

   23. glycolysis (cytoplasm), citric acid cycle (mitochondria), electron transport chain (mitochondria)

   24. What are four different functions of cell membranes?

   25. physical isolation (phospholipid bilayer); regulation of exchange, communication, structural support

   26. Simple diffusion

   27. passive; molecules go down their concentration gradient; equilibrium occurs when concentration is uniform

   28. Facilitated diffusion

   29. Passive; high to low concentration with aid of membrane-spanning proteins

   30. Osmosis

   31. passive; movement of water from low to high solute concentration

   32. Active Transport

   33. active; requires ATP; low to high; ex. sodium-potassium pump

   34. Gap Junctions

   35. form direct cytoplasmic connections between adjacent cells; found in: multi-unit smooth muscle

   36. Contact-dependent signals

   37. require interaction between membrane molecules on two cells; N-CAMs: nerve cell adhesion molecules

   38. “local” communication

   39. communication over short distances; includes intracrines, autocrines, paracrines

   40. “long-distance” communication

   41. communication over long distances; includes hormones, neurotransmitters, neurohormones, and neurocrines

   42. Intracrine

   43. signals within cell (cAMP, Ca++)

   44. Autocrine

   45. act on same cell that secreted them

   46. Paracrine

   47. secreted by one cell and diffuse to adjacent cells

   48. Neurocrine

   49. any chemical messenger produced by neuron

   50. Ectocrine

   51. produced by one organism to affect another organism (pheromones)

   52. Lipophilic molecule

   53. inside the cell (peptide and catecoleamines)

   54. Lipophobic molecule

   55. outside cell on the cell membrane (thyroid and steroid)

   56. Receptor channel

   57. direct; ligand binding opens or closes channel

   58. G Protein-coupled receptor

   59. 2nd messenger; ligand binding opens ion channel or alters enzyme activity

   60. Integrin receptor

   61. catalytic receptor; 2nd messenger; alters enzymes or the cytoskeleton

   62. Receptro-enzyme

   63. catalytic receptor; 2nd messenger; activates an intracellular enzyme

   64. Receptor agonist

   65. competes with primary ligand for binding to receptor; causes biological response

   66. Receptor antagonist

   67. blocks or inhibits receptors

Endocrinology

1. AA Berthold’s famous experiments

1. group 1: straight castration of roosters that lead to smaller roosters; group 2: castration and reimplantation of testis lead to normal male development; group 3: castration and transplantation of testis lead to normal male development

2. What are three classical ways to investigate the function of a suspected endocrine tissue?

   1. remove the suspected gland; replace the hormone or gland; create excess hormones

3. hypersecretion

   1. too much hormone

4. hyposecretion

   1. too little hormone

5. abnormal target-tissue response

   1. receptor or 2nd messenger problem

6. Hydrophilic messengers

   1. secreted by exocytosis and dissolved into blood (insulin, glucagon, FSH)

7. hydrophobic messengers

   1. secreted by diffusion, bound to protein carriers in blood vessel; 99% in blood and 1% free (estrogen, testosterone, cortisol)

8. What is a hormone binding protein? Why and when are they necessary?

   1. proteins that bind to hormones after secretion into bloodstream; 1. significantly improves half-life of protein, 2. reduces minute to minute fluctuations in hormone concentration

9. Steroid hormones

   1. modifications of cholesterol in cell membrane; made on demand; lipophilic (exit cell via simple diffusion); need to bind to carriers in blood; ex. cortisol, testosterone

   2. peptide hormones

   3. short chains of amino acids (2-50 AA chains); most common type of hormone; made in advance in rough ER; released into circulation into exocytosis; made as prohormones that must be cleaved to activate; ex. insulin

   4. Catecholamines

   5. activation of second messenger systems; act like peptide hormones; secreted into blood = neurohormone; ex. epinephrine, dopamine

   6. Thyroid hormones

   7. activation of genes for transcription and translation; act like steroid hormones; bound to carrier proteins; ex. Thyroxine

   8. Amine hormones

   9. 2 types: catecholamines and thyroid hormones; modifications of single amino acids; released from cell via exocytosis

   10. Describe five factors influencing the response of target cells to hormones.

   11. concentration of hormone, concentration of receptors, binding affinity of receptor to hormone, type of tissue, type of receptor

   12. Describe a generic endocrine pathway (i.e. hormone axis).

   13. Hypothalamus targets pituitary gland by releasing hormone; pituitary releases a stimulating hormone into blood stream; stimulating hormone causes distal (primary) endocrine glands to release hormone

   14. Name the four different hypothalamic-pituitary axes discussed in lecture. What are the main
       functions of each primary hormone?

   15. Hypothalamus-pituitary-thyroid (HPT); Hypothalamus-pituitary-adrenal gland (HPA); Hypothalamus-pituitary-gonads, hypothalamus-pituitary-liver

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