Term
| The volume inspired or expired with each normal breath is known as what? |
|
Definition
|
|
Term
| The volume that can be inspired over and above the tidal volume that is used during exercise is known as what? |
|
Definition
| Inspiratory reserve volume |
|
|
Term
| The volume that can be expired after the expiration of a tidal volume is known as what? |
|
Definition
| Expiratory reserve volume |
|
|
Term
| The volume that remains in the lungs after a maximal expiration that cannot be measured by spirometry is known as what? |
|
Definition
|
|
Term
| The volume of the conducting airways is known as what? |
|
Definition
|
|
Term
| What is the normal average anatomic dead space volume? |
|
Definition
|
|
Term
| The volume of the lungs that does not participate in gas exchange is known as what? |
|
Definition
|
|
Term
| How is physiologic dead space calculated? |
|
Definition
| Vd = Vt * (PaC02 - PeC02)/PaC02 |
|
|
Term
| How is minute ventilation calculated? |
|
Definition
| Tidal volume * breaths/min |
|
|
Term
| How is alveolar ventilation calculated? |
|
Definition
| (Tidal volume - dead space) * breaths/min |
|
|
Term
| What is inspiratory capacity? |
|
Definition
| The sum of the tidal volume and the inspiratory reserve volume |
|
|
Term
| The sum of the expiratory reserve volume and the residual volume is known a what? |
|
Definition
| Functional residual capacity - the volume remaining int he lungs after a tidal volume is expired |
|
|
Term
| The volume of air that can be forcibly expired after a maximal inspiration is known as what? |
|
Definition
| Vital capacity or forced vital capacity - the sum of the tidal volume, inspiratory reserve volume, and expiratory reserve volume |
|
|
Term
| The volume in the lungs after a maximal inspiration that is the sum of all four lung volumes is known as what? |
|
Definition
|
|
Term
| The volume of air that can be expired in the first second of a forced maximal expiration is known as what? |
|
Definition
| Forced expiratory volume - normally 80% of the forced vital capacity |
|
|
Term
| The distensibility of the lungs and the chest wall is known as what? |
|
Definition
| Compliance of the respiratory system |
|
|
Term
| Compliance is inversely related to what? |
|
Definition
|
|
Term
| How is compliance represented on the pressure-volume curve? |
|
Definition
|
|
Term
| How is compliance of the respiratory system observable? |
|
Definition
| As the change in volume for a given change in pressure |
|
|
Term
| What is transmural pressure? |
|
Definition
| Alveolar pressure - intrapleural pressure |
|
|
Term
| What is the effect of negative intrapleural pressure on respiration? Positive intrapleural pressure? |
|
Definition
| Intrapleural pressure = pressure outside the lungs. If it is negative, lungs expand, lungs collapse if it is positive |
|
|
Term
| The difference in the curve between inflation and deflation of the lungs is known as what? |
|
Definition
|
|
Term
| When is compliance greatest and the lungs most distensible? |
|
Definition
| In the middle range of pressures |
|
|
Term
| What is the effect on the lungs when lung compliance increases? Decreases? |
|
Definition
| Increased compliance decreases the tendency of the lungs to collapse (emphysema), decreased compliance increases the tendency of the lungs to collapse (fibrosis) |
|
|
Term
|
Definition
| Collapsing pressure is directly proportional to the surface tension of the alveoli and inversely proportional to alveolar radius |
|
|
Term
| What equation represents Laplace's law? |
|
Definition
| P = 2T/r where P = collapsing alveolar pressure, T = surface tension, r = alveolar radius |
|
|
Term
| Which have lower collapsing pressures, large or small alveoli? What is the consequence of a large or small alveolar radius? |
|
Definition
| Large have low collapsing pressures and thus easier to keep open |
|
|
Term
| What reduces the surface tension of alveoli by disrupting the intermolecular forces between molecules of liquid? |
|
Definition
|
|
Term
| What is the effect of surfactant on compliance? |
|
Definition
|
|
Term
| What synthesizes surfactant? |
|
Definition
|
|
Term
| What is the primary ingredient in surfactant? |
|
Definition
| Dipalmitoyl phosphatidylcholine (DPPC) |
|
|
Term
| What constitution of amniotic fluid reflects mature levels of surfactant in a fetus? |
|
Definition
| 2:1 ratio of lecithin to sphingomyelin |
|
|
Term
|
Definition
| Directly proportional to the pressure difference between the mouth/nose and the alveoli |
|
|
Term
| Airflow is inversely proportional to what? |
|
Definition
| Airway resistance, shown in Q = deltaP/R |
|
|
Term
| What is Pioseuille's law? |
|
Definition
| R = (8nl)/(pi*r^4), shows resistance is inversely proportional to the resistance to the fourth power |
|
|
Term
| What is the major site of airway resistance? |
|
Definition
|
|
Term
| What affect does parasympathetic stimulation have on airways |
|
Definition
| Constricts airways, decreases radius, and increases the resistance to airflow |
|
|
Term
| What affect does sympathetic stimulation have on airways? |
|
Definition
| Dilates airways via beta-2 receptors, increases radius, decreases resistance to airflow |
|
|
Term
| What is the state of respiratory system during the breathing cycle at rest? |
|
Definition
| Alveolar pressure (equals 0) equals atmospheric pressure, intrapleural pressure is negative, lung volume is the functional residual capacity |
|
|
Term
| What is the state of the respiratory system during the breathing cycle at inspiration? |
|
Definition
| Volum eof the thorax increases, alvoelar pressure decreases below atmospheric pressure, the pressure gradient causes airflow into the lungs, lung volume increases by one tidal volume |
|
|
Term
| What is the state of the respiratory system during the breathing cycle at expiration? |
|
Definition
| Alveolar pressure becomes greater than atmospheric pressure, air flows out of the lungs, lung volume returns to functional residual capacity |
|
|
Term
| What are the characteristics of asthma in relation to the breathing cycle? |
|
Definition
| Expiration is impaired, decreased forced vital capacity, air cannot be properly expired and is trapped, increasing functional residual capacity |
|
|
Term
| The combination of chronic bronchitis and emphysema is referred to as what? |
|
Definition
|
|
Term
| What are the characteristics of COPD in relation to the breathing cycle? |
|
Definition
| Obstructive disease with increased lung compliance with impaired expiration, has decreased forced vital capacity, increased functional residual capacity |
|
|
Term
| What are the characteristics of fibrosis in relation to the breathing cycle? |
|
Definition
| Decreased lung compliance with impaired inspiration, decreases all lung volume, often increases FEV1/FVC ratio |
|
|
Term
| What is Dalton's law of partial pressures? |
|
Definition
| Partial pressure = total pressure * fractional gas concentration |
|
|
Term
| Why is the PO2 of arterial blood slightly lower than that of alveolar air? |
|
Definition
| Approximately 2% of systemic cardiac output bypasses pulmonary circulation, resulting in a mixture of venous blood with oxygenated arterial blood |
|
|
Term
| The amount of gas dissolved in a solution is proportional to what? |
|
Definition
|
|
Term
| The diffusion rates of O2 and Co2 depend on what? |
|
Definition
| Partial pressure differences across the membrane and the area available for diffusion |
|
|
Term
| What occurs in perfusion-limited exchange? |
|
Definition
| Deals with N20 and 02 under normal conditions. Gas equilibrates early along the length of the pulmonary capillary. The partial pressure of the gas in arterial blood becomes equal to the partial pressure in alveolar air |
|
|
Term
| How is gas exchanged increased in perfusion-limited exchange? |
|
Definition
| Only if blood flow increases |
|
|
Term
| What occurs in diffusion limited exchange? |
|
Definition
| Deals with CO and O2 during strenuous exervis, seen in disease states, gas does not equilibrate by the time blood reaches the end of the pulmonary capillary, diffusion continues as long as partial pressure gradient is maintained |
|
|
Term
| How is O2 carried in the blood? |
|
Definition
| Either dissolved or bound to hemoglobin |
|
|
Term
| In what state does iron in iron-containing porphyrin bind oxygen? |
|
Definition
|
|
Term
| What is normal adult hemoglobin referred to as? |
|
Definition
| Alpha-2 Beta-2 due to the chains in its subunits |
|
|
Term
| What is fetal hemoglobin referred to as? |
|
Definition
| Alpha-2 and Gamma-2 due to the chains in its subunits |
|
|
Term
| Why is the O2 affinity of fetal hemoglobin than in adult hemoglobin? |
|
Definition
|
|
Term
| The maximum amount of O2 that an be bound the hemoglobin is referred to as what? |
|
Definition
|
|
Term
| O2 capacity is dependent on what? |
|
Definition
|
|
Term
| The total amount of O2 carried in blood including bound and dissolved O2 is referred to as what? |
|
Definition
|
|
Term
| O2 content depends on what? |
|
Definition
| Hemoglobin concentration, the PO2, and the P50 of hemoglobin |
|
|
Term
| How is O2 content calculated? |
|
Definition
| (O2-binding capacity * %saturation) + dissolved O2 |
|
|
Term
| Hemoglobin combines rapidly and reversibly with O2 to form what? |
|
Definition
|
|
Term
| How is the hemoglobin-O2 dissociation curve polotted? |
|
Definition
| Plot of percent saturation of hemoglobin as a function of PO2 |
|
|
Term
| At what PO2 is hemoglobin almost 100% saturated? |
|
Definition
| 100mm Hg (arterial blood) |
|
|
Term
| What causes the sigmoid shape of the hemoglobin-O2 dissociation curve? |
|
Definition
| Change in the affinity of hemoglobin as each successive O2 molecule binds to a heme site (positive cooperativity) |
|
|
Term
| When does the hemoglobin-O2 dissociation curve shift to the right? |
|
Definition
| When the affinity of hemoglobin for O2 is decreased, P50 of hemoglobin is increased, increased pH, increased PCO2, increases in temperature, increases in DPG, or if the percent saturation of hemoglobin is decreased |
|
|
Term
| What are the effects of a shift of the hemoglobin-O2 dissociation curve to the right? |
|
Definition
| Decreases the affinity of hemoglobin for O2, O@ is unloaded in the tissues )Bohr effect) |
|
|
Term
| What shifts the hemoglobin-O2 dissociation curve to the left? |
|
Definition
| Affinity of hemoglobin for O2 is increased, P50 is decreased, decreased PCo2, increased pH, decreased temp, decreased DPG |
|
|
Term
| What effect does carbon monoxide (CO) have on the hemoglobin-O2 curve? |
|
Definition
| Increases the affinity of remaining sites for O2 in hemoglobin, causes shift of the curve to the left |
|
|
Term
| What are the three forms of CO2 found in the body? |
|
Definition
| Dissolved CO2m carbaminohemoglobin, HCO3- (major form 90%) |
|
|
Term
| What catalyzes the reaction that combines CO2 with H20 to form H2CO3 in RBCs? |
|
Definition
|
|
Term
| HCO3- leaves RBCs in exchange for what? |
|
Definition
|
|
Term
| How is CO2 generated by tissues expired? |
|
Definition
| In the lungs, HCO3- enters RBCs for exchange of Cl-, recombines with H+ to form H2CO3 which decomposes into CO2 and H2O, allowing it to be expired |
|
|
Term
| Are pressures and resistance lower int he pulmonary circulation or in the systemic circulation? |
|
Definition
|
|
Term
| What affect does gravity have on the distribution of pulmonary blood flow? |
|
Definition
| When a person is standing, blood flow is lowest at the apex, highest at the base of the lung, therefore V/Q ratio is highest at the apex (V=ventilation) and gas exchange is more efficient, though greatest gas exchange still occurs at base due to greater blood flow |
|
|
Term
| Where is gas exchange highest in a standing individual? |
|
Definition
|
|
Term
| What sensory signals have an effect on breathing and where is sensory information coordinated? |
|
Definition
| PCO2, lung stretch, irritants, muscle spindles, tendons, and joints - coordinated in the brainstem |
|
|
Term
| What is the central control of breathing? |
|
Definition
| Medullary respiratory center located in the reticular formation |
|
|
Term
| Which part of the central control for breathing is responsible for inspiration? |
|
Definition
| Dorsal respiratory group - generates basic rhythm for breathing |
|
|
Term
| Input tot he dorsal respiratory group comes from what? |
|
Definition
| Vagus (peripheral chemoreceptors and mechanoreceptors in the lung) and glossopharyngeal (peripheral chemoreceptors) nerves |
|
|
Term
| Output from the dorsal respiratory group travels along what nerve? |
|
Definition
| Phrenic nerve to the diaphragm |
|
|
Term
| What part of the medullary respiratory center controls expiration? |
|
Definition
| Ventral respiratory group |
|
|
Term
| When is the ventral respiratory group active? |
|
Definition
| During exercise, not active during passive expiration |
|
|
Term
| Where is the apneustic center located? |
|
Definition
|
|
Term
| What is the function of the apneustic center? |
|
Definition
| Stimulates inspiration, produces a deep and prolonged inspiratory gasp |
|
|
Term
| What is the location of the pneumotaxic center? |
|
Definition
|
|
Term
| What is the function of the pneumotaxic center? |
|
Definition
| Inhibits inspiration, regulates inspiratory volume and respiratory rate |
|
|
Term
| What part of the CNS is the voluntary control center for breathing? |
|
Definition
|
|
Term
| Central chemoreceptors in the medulla are sensitive to what? |
|
Definition
| Drop in pH (increases breathing) of the cerebrospinal fluid and increased PCO2 (Increases breathing) |
|
|
Term
| Peripheral chemoreceptors in the carotid and aortic bodies are sensitive to what? |
|
Definition
| Decrease of PO2 (increases breathing), increases in PCO2 (increases breathing), and a drop in pH (increases breathing) |
|
|
Term
| Where are lung stretch receptors located? |
|
Definition
| Smooth muscle of the airways |
|
|
Term
| What is the response to activating lung stretch receptors? What is this reflex called? |
|
Definition
| Hering-Breuer reflex, stimulates decrease in breathing frequency |
|
|
Term
| Where are irritant receptors located? |
|
Definition
| Between airway epithelial cells, triggered by noxious substances |
|
|
Term
| Where are J (juxtacapillary) receptors located? |
|
Definition
| Alveolar walls close to the capillaries |
|
|
Term
| What triggers J (juxtacapillar) receptors and what response does they trigger? |
|
Definition
| Engorgement of pulmonary capillaries such as in left heart failure, causes rapid shallow breathing |
|
|
Term
| What activates joint and muscle receptors and what do they stimulate? |
|
Definition
| Activated during exercise, involved in early stimulation of breathing |
|
|
Term
| Do the mean values for arterial PO2 and PCO2 change during exercise? |
|
Definition
|
|
Term
| What is the change in venous PCO2 during exercise? |
|
Definition
| Increases due excess CO2 production by exercising muscles |
|
|
Term
| Why is alveolar PO2 decreased at high altitude? |
|
Definition
| Due to decrease in barometric pressure, reduces arterial PO2 |
|
|
Term
| Where is laminar airflow most common? |
|
Definition
| Small airways such as in alveoli, occurs at low airflow rate, is parallel to the walls of the airway, and is silent |
|
|
Term
| Where is turbulent airflow most common? |
|
Definition
| Trachea and large airways, occurs at high velocity and high radius of the tube, detectable by stethescope |
|
|
Term
| What is the major site of resistance in the lungs? |
|
Definition
|
|
Term
| Is airway resistance parallel or in series? |
|
Definition
|
|
Term
| Pulmonary resistance is defined as what? |
|
Definition
| Airway resistance + lung parenchyma resistance |
|
|
Term
| The diameter of an airway is determined by what two opposing forces? |
|
Definition
| Inward smooth muscle/elastic forces, outward transpulmonary pressure and alveoli septa |
|
|
Term
| What factors constrict bronchial smooth muscle, increasing resistance? |
|
Definition
| Parasympathetic stimulation, Ach, histamine, serotonin, drop in PCO2 in small airways |
|
|
Term
| What factors dilate bronchial smooth muscle, decreasing resistance? |
|
Definition
| Sympathetic stimulation, beta-2 adrenergic agonists, NO, increased PCO2 and a drop in PO2 in small airways |
|
|
Term
| What are the most common causes of increased airway resistance? |
|
Definition
| Swelling of the bronchial wall as in edema, obstruction, bronchospasm (constriction of airways smooth muscle) |
|
|
Term
| What is dynamic compliance? |
|
Definition
| The change in the volume of the lung divided by the distending pressure during the course of breathing |
|
|
Term
| How is dynamic compliance calculated? |
|
Definition
| As the slope of the line between the end inspiratory and end expiratory points |
|
|
Term
| What effect does surfactant have on dynamic compliance? |
|
Definition
| Increased surfactant increases dynamic compliance |
|
|
Term
| How is work of breathing calculated? |
|
Definition
| W = pressure * change in volume |
|
|
Term
| What factors must be overcome during the work of breathing? |
|
Definition
| Elastic and resistive components |
|
|
Term
| What is the function of spirometry? |
|
Definition
| Measures functional residual capacity (FRC) |
|
|
Term
| What is the function of plethysmography? |
|
Definition
| Measures lung volumes and the functional residual capacity (FRC) |
|
|
Term
| How is spirometry used with helium measure the FRC? |
|
Definition
| Known concentration and volume of helium is breathed in a closed spirometer system until the helium concentration reaches the plateu and equals the concentration of He in the spirometer and the subject's lungs which is then calculated using the mass balance equation |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| What is principle is exhibited by Henry's law? |
|
Definition
| Volume of dissolved gas is proportional to partial pressure |
|
|
Term
| What is LaPlace's law and what does it mean? |
|
Definition
| Net pressure ina gas filled sphere is dependent on surrounding surface tension and radius of the sphere: P = (2T)/r, meaning surface forces in a smaller sphere generate higher pressure |
|
|
Term
| What is the chief ingredient in surfactant? |
|
Definition
| DPPC, dipalmytolphosphatidylcholine |
|
|
Term
| Blood acidosis and alkalosis revolves around what pH value? |
|
Definition
|
|
Term
| What effect does hypoventilation have on blood pH |
|
Definition
|
|
Term
| What effect does hyperventilation have on blood pH |
|
Definition
|
|
Term
| What defines an acute respiratory acid base disorder? |
|
Definition
| No compensations due to a lack of sufficient time such as in the use of a narcotic or respiratory depressant |
|
|
Term
| What defines a chronic respiratory acid base disorder? |
|
Definition
| Changes in gas exchange occur slowly, body compensates via kidneys, however the pH is not yet 7.4 |
|
|
Term
| What defines a compensated respiratory acid base disorder? |
|
Definition
| pH value is normal due to compensation but HCO3- and PCO2 values may or not be inthe normal stage |
|
|
Term
| How do you differentiate between respiratory and metabolic acidosis? |
|
Definition
| If PCO2 contributes to the conditions, it indicates respiratory acidosis |
|
|
Term
| What is stated by Henry's Law? |
|
Definition
| At constant temp, the amount of a given gas dissolved ina given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid |
|
|
Term
| Asexual reproduction occurs via what method? |
|
Definition
| Mitosis - the creation of new diploid cells from diploid cells, offspring with identical genotype and phenotypes |
|
|
Term
| Sexual reproduction occurs via what method? |
|
Definition
| Haploid gamete production via meiosis, offspring have different phenotypes |
|
|
Term
| What regulates the reproduction system? |
|
Definition
| Hypothalamic-pituitary-gonadal axis |
|
|
Term
| The testes and ovaries are responsible for the primary production of what sex steroids? |
|
Definition
| Testosterone and estrogen |
|
|
Term
| How do sex steroids circulate? |
|
Definition
| Bound to sex steroid binding globulin (SSBG) or albumin, progesterone specifically circulates bound to corticosteroid binding globulin (CBG) |
|
|
Term
| Normal levels of testosterone, progesterone, and estradiol 17-beta vary depending on what? |
|
Definition
| Age, gender, health status, time of day, and/or phase of menstrual cycle |
|
|
Term
| Where are coricotsteroids and mineral corticoids used as sex steroids metabolized? |
|
Definition
| Liver and excreted in urine, half life is about 30-60 minutes |
|
|
Term
| What is the path of sex steroid synthesis? |
|
Definition
| Acetate -> cholesterol -> pregnolone -? 17 alpha-hydroxypregnenolone -> DHEA -? androstendiol -> testosterone |
|
|
Term
| How many carbons are in androgens? |
|
Definition
|
|
Term
| How many carbons are in estrogens? |
|
Definition
|
|
Term
| 5a-reductase is found primarily in what kind of cells? |
|
Definition
| Testosterone target cells |
|
|
Term
| What are the important sex steroid androgens? |
|
Definition
| Testosterone: androstenedione (extragalandular estrogen precursor in men), DHEA, DHT |
|
|
Term
| What produces testosterone in men? |
|
Definition
|
|
Term
| What supplies the androgenic hormone requirement in women? |
|
Definition
| Adrenals, but they do not play a large role until after menopause |
|
|
Term
| Androgens are required for what in women? |
|
Definition
|
|
Term
|
Definition
| Estradiol 17-beta, estrone, estriol |
|
|
Term
| What produces estrogen in women? |
|
Definition
| Granulosa and thecal cells of ovary |
|
|
Term
| What produces progesterone? |
|
Definition
| Corpus luteum and later placenta |
|
|
Term
| What produces gonadotropin releasing hormone (GnRH)? |
|
Definition
| Produced in arcuate nucleus and preoptic area of hypothalamus |
|
|
Term
|
Definition
| As a preprohormone (92AA) cleaved to a prohormone (69AA) and then cleaved to make a decapeptide, also produces residual 56AA peptide called GnRH associated hormone (GAP) |
|
|
Term
| What is the function of GnRH? |
|
Definition
| Binds to the plasma membrane of gonadotrophs in the pituitary, stimulates release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) in both males and females |
|
|
Term
| LH and FSH are considered what type of proteins? |
|
Definition
| Glycoproteins with alpha and beta subunits, beta-chain confers specificity |
|
|
Term
| What is the normal result of a lack of sexual differentiation during development? |
|
Definition
|
|
Term
| What is a true hermaphrodite? |
|
Definition
| Individuals who have both male and female gonads |
|
|
Term
| What is a pseudohermaphrodite? |
|
Definition
| Individuals with the gonads of one sex bu tthe external genitalia of the opposite sex or both sexes |
|
|
Term
| What type of in-utero gonadal cells are seen in both males and females up to the first 5 weeks of development? |
|
Definition
| Coelomic epithelial and mesenchymal stromal cells, gonads are indifferent |
|
|
Term
| Coelomic epithelial cells are precursors to what? |
|
Definition
| Granulosa and sertoli cells |
|
|
Term
| Mesenchymal stromal cells are precursors to what? |
|
Definition
|
|
Term
| When does gonadal differentiation occur in males? |
|
Definition
| 6-7 weeks, semineferous tubules form and sertoli cells enclose germ cells |
|
|
Term
| When doe Leydig cells begin to appear? |
|
Definition
|
|
Term
| When does sex differentiation occur in females? |
|
Definition
| 9 weeks, both X chromosomes activated, germ cells undergo mitosis giving rise to oogonia, meiosis initiated in some oogonia surrounded by granulosa cells and stroma, theca cells develop from stroma, cells are arrested in late prophase |
|
|
Term
| What part of the short arm of the Y chromosome allows for the development of the testes? |
|
Definition
| Sex-determining Region of Y chromosome (SRY) |
|
|
Term
| Which sex chromosome contains the gene that encodes for androgen receptors? |
|
Definition
|
|
Term
| What sexual characteristic is present in the early embryo regardless of sex? |
|
Definition
| Wolffian duct (future male internal reproductive tract) and mullerian duct (future female internal reproductive tract) |
|
|
Term
| When are testes fully functional in development? |
|
Definition
| Appear at 7 weeks, functional in 14-16 weeks |
|
|
Term
| What two hormones produced by fetal testes is required for the development of male genitalia? |
|
Definition
| Testosterone (produced by leydig cells) and mullerian-inhibiting hormone (MIH) or anti-mullerian hormone (AMH) produced by sertoli cells |
|
|
Term
| What is the function of testosterone in sex development in the embryo? |
|
Definition
| Act in paracrine manner to stimualte development of Wolffian duct into epididymus, vas deferens, seminal vesicle, and ejaculatory ducts |
|
|
Term
| How does the absence of testosterone play a role in sex development in the embryo? |
|
Definition
| Wolffian duct regresses, Mullerian ducts become fallopian tubes, uterus, cerix, and 1/3 of vagina |
|
|
Term
| The common linkage for genitalia differentiation is based on the presence of what? |
|
Definition
| DHT from testosterone via 5-alpha reductase (present in males, absent in females) |
|
|
Term
| Genital tubercle is the common tissue for what? |
|
Definition
|
|
Term
| Genital swelling is the common tissue for what? |
|
Definition
|
|
Term
| Urethral fold is the common tissue for what? |
|
Definition
| Labia minora and penile shaft |
|
|
Term
| Urogenital sinus is the common tissue for what? |
|
Definition
| Lower vagina and prostate gland |
|
|
Term
| What are some genetic abnormalities we should know? |
|
Definition
| XO = Turners (streak gonad), XXY = Klinefelters, XXX = meta female |
|
|
Term
| What causes androgen insensitivity syndrome? |
|
Definition
| X-linked recessive defect that leads to the absence of androgen receptors on target tissues, displays male XY genotype but appears as female |
|
|
Term
| Where does spermatogenesis occur? |
|
Definition
| Lumen of the seminiferous tubule from the basement membrane into the lumen |
|
|
Term
| Seminiferous tubules are mostly made up of what cells? |
|
Definition
| Sertoli cells, composes 90% of the testes - basement layer, germinal epithelium, and Leydig cells make up the rest |
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|
Term
| The earliest sperm germ cells are what? When do they appear? |
|
Definition
| Spermatogonia, first appears 6-7 weeks |
|
|
Term
| 1 spermatogonium gives rise to how many spermatids? |
|
Definition
| 4 spermatids, only requires adequate testosterone for spermatogenesis |
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|
Term
|
Definition
| Release of spermatozoa into seminferous tubule (still immature) |
|
|
Term
| Where does spermatozoa maturation occur? How long does this process take? |
|
Definition
| 24 days in the epididymis, moved forward by fluid and muscle contraction of epididymys |
|
|
Term
| What are the 4 sections of spermatazoa? |
|
Definition
| Head w/haploid chromosome, middle piece with mito for ATP, principle piece that stores ATP, end piece flagellum |
|
|
Term
| How many days total does it take to produce spermatozoa? |
|
Definition
| 74 days - 50 days in seminiferous tubule and 24 days in epididymis |
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|
Term
| Testosterone is concentrated in what part of the seminiferous tubule/ |
|
Definition
|
|
Term
| What is the function of Leydig cells in sperm production? |
|
Definition
| De novo synthesis of cholesterol (or acquisition), converts progesterone to androstenedion via 17-beta-hydroxysteroid dehydrogenase (17-beta-HSD) to produce testosterone |
|
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Term
| How are sertoli cells involved in sperm production? |
|
Definition
| Expresses androgen receptor AR and FSH receptor, produces anti-mullerian hormone, and aromatization of testosterone to estradiol-17-beta (local effect not only endocrine) |
|
|
Term
| How do Leydig cells express LH receptors and what are their effects? |
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Definition
| Hydrolysis of cholesterol esters and expression of StAR (transfers cholesterol to inner mito membrane), results in overall increase in testosterone |
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|
Term
| How doe Sertoli cells express FSH receptors and what are their effects? |
|
Definition
| Stimulates protein synthesis of "nursing" function of cells, synthesis of inhibin B which exerts negative feedback on FSH production |
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|
Term
| Testosterone produces negative feedback on what compounds? |
|
Definition
| GnRH release and LH release |
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|
Term
| Which do testosterone, DHT, and estrogen selectively inhibit more, LH or FSH? |
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Definition
|
|
Term
| What does inhibin directly inhibit? |
|
Definition
|
|
Term
| How does intra-testicular levels of testosterone compare to level in the blood? |
|
Definition
| Over 100 times greater, required to maintain spermatogenesis |
|
|
Term
| Administration of exogenous testosterone leads to what endocrine effects? |
|
Definition
| Inhibition of GnRH and pituitary gonadotrophs, specifically decreases LH production |
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Term
| What is the result of the peripheral binding of testosterone and DHT to androgen receptors (AR) in the cytoplasm of cells? |
|
Definition
| Nuclear translocation of androgen-AR complex, dimerization and binding of androgen response elements, leads to transcription |
|
|
Term
| What peripheral effect does testosterone have via androgen receptors? |
|
Definition
| Lipid profile (increased VLDL and LDL, decreased HDL), changes in larynx, increases lean mass, hematocrit, visceral abdominal fat |
|
|
Term
| What peripheral effect does DHT have? |
|
Definition
| Secondary sex characteristic changes in sebaceous glands, hair growth patterns |
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|
Term
| How is estrogen produced peripherally? |
|
Definition
| Via testosterone's conversion in adipose and the liver, plays a role in bone maturation |
|
|
Term
| The majority of circulating testosterone is bound to what? |
|
Definition
| 60% androgen binding protein (APB), 38% bound to albumin and 2% free, testosterone and its metabolites excreted in urine |
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|
Term
| What occurs in males to GnRH levels as puberty approaches? |
|
Definition
|
|
Term
| What initiates 1st degree male sex characteristics? |
|
Definition
| Increased LH (and thus testosterone), increased FSH (and thus inhibin from Sertoli cells), increased testicular size and sperm production |
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|
Term
| What secondary sex characteristics are initiated by androgens in males? |
|
Definition
| Due to both testosterone and adrenal androgens, pubertal growth spurt, penile growth and pubic hair, facial hair |
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|
Term
| What secondary sex characteristics are initiated by anabolic factors in males? |
|
Definition
| Muscle growth and development |
|
|
Term
| Sperm accounts for how much of seminal fluid? |
|
Definition
|
|
Term
| Seminal vesicles contribute what to semen? |
|
Definition
| ~60% of volume, alkaline fructose fluid with prostaglandins, sperm |
|
|
Term
| What is the final pH of semen? |
|
Definition
|
|
Term
| What role do prostate gland secretions have in semen? |
|
Definition
| 30% volume, activates sperm via milky, slightly alkaline fluid with citrate as a nutrient source, prostate specific antigen that participates in the dissolution of seminal fluid coagulum and phosphate bicarbonate buffers |
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|
Term
| What is the role of bulburethral (cowper's) glands in semen? |
|
Definition
| Secretes alkaline mucus-like fluid, neutralizes the acidity of the urine residue in the urethra, helps neutralize acidity of the vagina, provides some lubrication for the tip of the penis during intercourse |
|
|
Term
| What's the path of sperm from the seminiferous tubbule to ejaculation? |
|
Definition
| Lumen of seminiferous tubule -> rete testes -> epididymis -> vas deferens/ampulla of vas deferens/urethra -> penile urethra -> ejaculation |
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|
Term
| Erection is primarily achieved via what nervous input? |
|
Definition
| Parasympathetic via ACh binding to muscarinic receptors, leads to activation of NO synthase and release of NO, NO diffuses to vascular smooth muscle and stimulates cGMP to cause vasodilation |
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|
Term
| Menopause is marked by sustained levels of what? |
|
Definition
|
|
Term
| When does female puberty usually begin and end? |
|
Definition
| 8-9 yrs to 11-16 yrs of age |
|
|
Term
| How are primary sex characteristic development in females initiated? |
|
Definition
| Pulsatile release of GnRH results in pulsatile LH and FSH release leading to an increase in estrogen and androgens from the ovary |
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|
Term
| The ovarian follicle can be histologically described as what? |
|
Definition
| One germ cell completely surrounded by a cluster of endocrine cells, works to maintain and nurture the oocyte |
|
|
Term
| From weeks 8-9 to 6 months after birth, some oogonia enter what stage of meiosis I and remain suspended in that phase until sexual maturity? |
|
Definition
|
|
Term
| When do primary oocytes become primordial follicles? |
|
Definition
| Once a layer of granulosa cells surrounds the oocyte and a basil lamina is formed on the outside of the granulosa cells |
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|
Term
| After puberty, the formation of a secondary follicle from a primary follicle is characterized by what? |
|
Definition
| Additional thecal layer of cells |
|
|
Term
| Post pubertal follicular development is under the control of what? |
|
Definition
|
|
Term
| When does Graafian follicle development begin? |
|
Definition
| At puberty and continues in 28 day cycles, cycles begin after menarche and requires 70-85 days |
|
|
Term
| What occurs during Graafian follicle development? |
|
Definition
| Vesicles of the secondary follicle coalesce forming a fluid filled antrum rich in estrogen produced by the granulosa and thecal cells |
|
|
Term
| Where does the oocyte sit within the antrum of the graafian follicle? |
|
Definition
| On a cluster of granulosa cells known as the cumulus oophorus |
|
|
Term
| Graafian follicles are selected for ovulation base don what? |
|
Definition
| Number of estrogen and FSH receptors |
|
|
Term
| Ovulation occurs under the influence of what? |
|
Definition
|
|
Term
| At ovulation, the 1st meiotic division yields what? |
|
Definition
| A secondary oocyte and the 1st polar body. Oocyte begins 2nd meiotic division but is suspended at metaphase II until insemination |
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|
Term
| Sperm penetrates what part of the oocyte? What is the immediate result? |
|
Definition
| Zona pellucida, completing the 2nd meitic division forming the ootid and the 2nd polar body |
|
|
Term
| What cells form the corpus luteum? |
|
Definition
| Corpus hemorrhagicum and its granulosa and theca interna cells under the influence of LH |
|
|
Term
| The corpus luteum produces what? |
|
Definition
| Progesterone and persists if pregnancy ensues |
|
|
Term
|
Definition
| The process by which any stage follicle degenerates and dies |
|
|
Term
| Primary oocytes are arrested in what meitotic phase? |
|
Definition
| Completes meiosis I just prior to ovulation and is arrested in metaphase II |
|
|
Term
| BnRH binds the plasma membrane of gonadotrophs in the pituitary to stimulate what in females? |
|
Definition
|
|
Term
| How is estrogen formed in women? |
|
Definition
| LH stimulate theca cells via cAMP, increases synthesis of LDL and HDL receptors, theca increases androstenedione synthesis which is used by granulosa cells, FSH stimulates granulosa cells to produce aromatase which converts to estrone and then to estradiol via 17-beta-HSD |
|
|
Term
| What kind of cells are required for estrogen production in females? |
|
Definition
| Granulos and thecal cells |
|
|
Term
| FASH induces expression of what on granulosa cells? |
|
Definition
| LH receptors in late follicular fase, allows granulosa cells to maintain high levels of aromatase as FSH levels fall |
|
|
Term
| The menstrual cycle is typically how long? |
|
Definition
|
|
Term
| The follicular and luteal phase occurs in what organ? |
|
Definition
|
|
Term
| The menstrual, proliferative, and secratory phase of the menstrual cycle occurs in what organ? |
|
Definition
|
|
Term
| What occurs in the follicular phase? |
|
Definition
| Onset of menstrual bleeding, averages 15 days, characterized by recruitment and growth of 13-20 antral follicles due to FSH stimulation |
|
|
Term
| What occurs in the ovulatory phase? |
|
Definition
| Culminates in ovulation, lasts 1-3 days, E and inhibin B feedback on FSH secretion, LH/FSH ratio increases, all but largest follicle with the most FSH receptors survives, ovulation induced by LH surge |
|
|
Term
| What occurs in the luteal phase? |
|
Definition
| Lasts 13-14 days, ends with menstrual bleeding |
|
|
Term
| What is the function of estrogen secreted by the dominant follicle? |
|
Definition
| Secreted rapidly near the end of late follicular phase, promotes + feedback of ant. pituitary and sensitizes it to GnRH, signals HPA, induces LH surge and ovulation 36 hrs, eventually terminates LH surge due to loss of + fedback of estradiol and increased progesterone |
|
|
Term
| What inhibits the growth of cohort follicles? |
|
Definition
| Estrogen secreted by the dominant follicle |
|
|
Term
| What is the first main event driven by the LH surge during ovulation? |
|
Definition
| Primary oocyte completes meiosis I and arrests in metaphase II and the germinal vesicle breakdown occurs ~30 hrs after LH surge, involves dissolution of nuclear envelope and interphase nuclear structure |
|
|
Term
| What is the second main event driven by the LH surge during ovulation? |
|
Definition
| Wall of follicle and ovary at the stigma is broken down with release of cumulus-oocyte (ovulation) 32-36 hrs after LH surge |
|
|
Term
| What is the third main event driven by the LH surge during ovulation? |
|
Definition
| Granulosa and thecal cells restructured and form corpus luteum, involves direct vascularization of granulosa cells to produce progesterone and estrogen, estrogen drops for 2 days as a result |
|
|
Term
| What occurs during the luteal phase of the ovarian cycle? |
|
Definition
| Initial drop in estrogen terminates + LH feedback, corpus luteum matures and increases estrogen and progesterone again causing - feedback on LH and FSH |
|
|
Term
| What occurs as a result of a lack of fertilization? |
|
Definition
| Corpus luteum regresses, estrogen, progesterone, and inhibin drop, gonadotroph is released from negative feedback, resultsin an increase in FSH, menses occurs |
|
|
Term
| When does the proliferative phase of the uterine cycle occur? |
|
Definition
| Coincides with follicular phase, rising estrogen induces stratum basal to grow, endometrial lining grows, estrogen induces progesterone receptors to prime the uterus to respond to progesterone during the luteal phase |
|
|
Term
| What is characteristic of the secretory phase of the uterine cycle? |
|
Definition
| Preparation for implantation under the influence of progesterone and estrogen, coincides with luteal phase, progesterone induces epithelial and stromal cell differentiation, uterine gland to fill with glycogen vacuoles to support embryo, inhibits endometrial growth, downregulates ER, induces inactivating isoferms of 17-beta-HSD to convert estrdaiol to inactive estrone to protect endometrium from induced cancer |
|
|
Term
| What characterizes the menstruation phase of the uterine cycle? |
|
Definition
| Non0fertile cycle as corpus luteum dies, sudden progesterone withdrawl, loss of lamina functionalis and sloughing of the uterine lining for 4-5 days, 25-35 ml of blood lost |
|
|
Term
| What characterizes the implantation window of the uterine cycle |
|
Definition
| Brief period of endometrial receptivity for implantations between day 16-19, fertilization normally occurs within 1 day of ovulation |
|
|
Term
| What changes occur in the vagina during the menstrual cycle? |
|
Definition
| Estrogen stimulates proliferation of epithelium and increases the cell glycogen content, progesterone increases desquamation of epithelial cells, glycogen is metabolized by lactobacilli, converted to lactic acid, maintains acidic environment |
|
|
Term
| What is responsible for the increase in basal body temp of 0.4-1 degree C during the menstrual cycle? |
|
Definition
|
|
Term
| How is the cervix affected during the menstrual cycle? |
|
Definition
| Estrogen stimulates production of alkaline mucous as an ideal environment for sperm, progesterone stimulates production of scant acidic mucous hostile to sperm |
|
|
Term
| How are the breasts affected during the menstrual cycle? |
|
Definition
| Estrogen enhances duct growth, progesterone responsible for alveolar development |
|
|
Term
| What effect does estradiol have on bones? |
|
Definition
| Involved in closure of long bones in both sexes, intestinal Ca absorption and renal re-absorption, promotes osteoblasts and apoptosis of osteoclasts for bone formation |
|
|
Term
| What impact does estrogen have on the liver? |
|
Definition
| Improves circulating lipoprotein profiles, increases expression of LDL receptors and circulating HDL |
|
|
Term
| What effect does estrogen and progesterone have on skin? |
|
Definition
| Increases collagen synthesis, suppresses matric metalloproteases, increases glycosaminoglycan production and wound healing |
|
|
Term
| What effect does estrogen have on the cardiovascular system? |
|
Definition
| Promotes vasodilation via increased production of NO |
|
|
Term
| What effect does estrogen have on the CNS? |
|
Definition
| Neuroprotective, inhibits neuronal cell death, blocks MAO that degrades serotonin (progesterone has opposite effect), alters mood as a result |
|
|
Term
| What effect does progesterone have on the kidney? |
|
Definition
| Acts as a competitive inhibitor for aldosterone, acts as a natriuretic action on the kidney |
|
|
Term
| What effect does estrogen and progesterone have on the adipose? |
|
Definition
| Lipolytic, decreases lipoprotein lipase activity and increases hormone-sensitve lipase, loss of estrogen results in accumulation of adipose |
|
|
Term
| What is the mechanism of action for estrogen and progesterone? |
|
Definition
| Passes through cell membrane, binds to the ER or PR receptors in cytosol, induces DNA to initiate transcription |
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