LEC 4 Exam.txt

  1.  1.1 Be able to tell the common characteristics between the endocrine and nervous system.
    Both facilitate Communication, Integration & Control

    Both regulate to maintain homeostasis.

    Both control by regulatory feedback loops.
  2. 1.2 Effector tissues for endocrine and nervous system.
    • Endocrine: Virtually all tissues
    • Nervous: Muscle & glandular only.
  3. 1.3 Effector cells for endocrine and nervous system.
    • Endocrine: Target cells throughout the body
    • Nervous: Postsynaptic cells in muscle and glandular tissue only
  4. 1.4 Chemical messenger secretors for endocrine and nervous system.
    • Endocrine: Glandular epithelial or neurosecretory cells (modified neurons)
    • Nervous: Neurons
  5. 1.5 Chemical messenger distance traveled for endocrine and nervous system.
    • Endocrine: Long (by way of circulating blood)
    • Nervous: Short (across microscopic synapse)
  6. 1.6 Location of receptors for endocrine and nervous system.
    • Endocrine: Plasma membrane or within cells
    • Nervous: Plasma membrane
  7. 1.7 Characteristics of regulatory effect between the endocrine and nervous system.
    • Endocrine: Slow to appear, but long lasting.
    • Nervous: Appears rapidly, but short-lived.
  8. 2.1 Describe the chemical classifications of hormones.
    • Steroids
      • Cortisol (hydrocortisone)
      • Aldosterone
      • Estrogens
      • Progesterone
      • Testosterone
    • Nonsteroids
      • Proteins – long strands of amino acids
        • Growth Hormone (GH)
        • Prolactin (PRL)
        • Parathyroid hormone (PTH)
        • Calcitonin (CT)
        • Adrenocorticotropic hormone (ACTH)
        • Insulin
        • Glucagon
      • Glycoproteins
        • Follicle-stimulating hormone (FSH)
        • Luteinizing hormone (LH)
        • Thyroid-stimulating hormone (TSH)
        • Human chorionic gonadotropin (hCG)
      • Peptides – smaller strands of amino acids
        • Antidiuretic hormone (ADH)
        • Oxytocin (OT)
        • Melanocyte-stimulating hormone (MSH)
        • Somatostatin (SS)
        • Thyrotropin-releasing hormone (TRH)
        • Gonadotropin-releasing hormone (GnRH)
        • Atrial natriuretic hormone (ANH)
      • Amino Acid derivatives – “single” amino acids
        • Amines: Norepinephrine (NE), Epinephrine (Epi), Melatonin
        • Iodinated amino acids: Thyroxine (T4), Triiodothyronine (T3)
  9. 2.2 Describe three functional classifications of hormones.
    • Tropic> – those that target other endocrine glands to stimulate their growth or secretion.
    • Sex – those that target reproductive tissues
    • Anabolic – those that stimulate anabolism (building) in their target cells.
  10. 3.1 Know the messengers of the 2 messenger systems.
    → The 1st & 2nd messenger systems apply to most all nonsteroid hormones.

    → The 1st messenger is the hormone itself, which binds to a specific receptor (a membrane protein) in the cell plasma membrane.

    → The 2nd messenger is created within the cell cytoplasm as a result of this 1st messenger attachment.

    • There are several, but the most important are:
      • cAMP (cyclic Adenine Mono-Phosphate created from ATP), which then activates or deactivates enzymes in the cytoplasm.
      • Ca++ is another mechanism that can form a 2nd messenger. In this case the cell membrane protein that the 1st messenger binds to will open a Calcium channel with which it is associated. The influx of Ca++ then binds with calmodilin, which forms a “complex” (the 2nd messenger), which then activates/deactivates enzymes.
  11. 3.2 Know the mechanisms of hormone action.
    → All steroid actions are via the mobile-receptor (or nuclear-receptor) model.

    → Because steroids hormones are all based on cholesterol, a lipid, they are hydrophobic. This has two consequences.

    → First, they travel through the blood bound to a plasma protein since plasma is mostly water, and must disassociate themselves to escape to the interstitial fluid.

    → Second, they easily penetrate the phospholipid cell membrane and travel to the nucleus (or cytoplasm) where they bind with a “free-floating” receptor to form a complex that initiates mRNA transcription.

    → Because protein synthesis is slow, steroid hormone action is slow at 45 minutes to 2 days for PROTEIN SYNTHESIS, but when acting as signal transduction modifiers in cell membranes, they can be fast. Also, steroid effects are in proportion to the amount of hormone secreted.

    Most nonsteroid hormones act via the 1st & 2nd messenger mechanism, which is the fixed-membrane-receptor model.

    → Nonsteroid effects are faster (several seconds to a few minutes - compared to steroid hormone effects) and they are disproportionately large compared to the amount of hormone secreted because the 1st messenger triggers a cascade of 2nd messengers.

    → The thyroid hormones: Thyroxine (T4) and Triiodothyronine (T3) are the nonsteroid exceptions to the fixed-membrane-receptor model. They follow the mobile-receptor model.
  12. Name some ways in which endocrine secretion can be controlled.
    Negative feedback and positive feedback loops. The simplest mechanism operates when an endocrine cell is sensitive to the physiological changes produced by its target cells. Another mechanism that may influence the secretion of hormones by a gland is input from the nervous system.
  13. Name two failures that can result in Diabetes Mellitus.
      1. Insulin hyposecretion from the pancreas
      2. Target cell insensitivity to Insulin
  14. 4. Describe antagonism, synergism, and permissiveness as these terms relate to hormone function.
    • Synergism - combinations of hormones have a greater effect on a target cell than the sum of the effects that each would have if acting alone.
    • Permissiveness - occurs when a small amount of one hormone allows a second hormone to have its full effect on a target cell; the first hormone "permits" the full action of the second hormone.
      • Epinephrine (which constricts vessels to raise BP) needs a small amount of thyroxin.
      • A small amount of cortical hormone allows pituitary growth hormone to have its full effect.
    • Antagonism - one hormone produces the opposite effect of another hormone. Antagonism between hormones can be used to "fine tune" the activity of target cells with great accuracy, signaling the cell exactly when (and by how much) to increase or decrease a certain cellular process.
  15. 5.1 Describe hypothalamus and be able to tell how this gland exerts control over the pituitary gland.
    It is part of the CNS and is the major link between the nervous and endocrine systems.

    It regulates the hypophysis, or pituitary gland, which is connected to it via the infundibulum.

    The comm and control from the hypothalamus to the adenohypophysis is via hormones delivered via the hypophyseal portal system.

    Hormones released from the neurohypophysis are created in the hypothalamus and simply stored in the neurohypophysis to be secreted via neurosecretory control from the hypothalamus.
  16. 5.2 Describe the hormones of the hypothalamus that are directed at the adenohypophysis.
    Growth hormone-releasing hormone (GHRH) - Nutrient metabolism and tissue growth.

    Growth hormone-inhibiting hormone (GHIH), or Somatostatin (SS) - Inhibits secretion of growth hormone. It is also an inhibitor of TSH.

    Corticotropin-releasinq hormone (CRH) - corticotrophs that stimulate release of adrenocorticotropic hormone (ACTH).

    Thyrotropin-releasing hormone (TRH) - thyrotrophs that stimulate release of thyroid-stimulating hormone (TSH) as well as Prolactin.

    Gonadotropin-releasing hormone (GnRH) - gonadotrophs that stimulate release of gonadotropins (FSH and LH).

    Prolactin-releasing hormone (PRH) - corticotroph that stimulates secretion of prolactin.

    Prolactin-inhibiting hormones (PIH) - corticotroph that inhibits secretion of prolactin.

    All of these hormones are classified as “Tropic” hormones because they target other endocrine glands. In this case the anterior pituitary.
  17. 5.3 Hypersecretion of growth hormone (GH) during adulthood.
    Acromegaly - Chronic metabolic disorder characterized by gradual enlargement or elongation of facial bones and extremities.
  18. 5.4 Hyposecretion of adrenal cortical hormones (adrenal cortical insufficiency).
    Addison disease - Caused by tuberculosis, autoimmunity, or other factors, this life-threatening condition is characterized by weakness, anorexia, weight loss, nausea, irritability, decreased cold tolerance, dehydration, increased skin pigmentation, and emotional disturbance; it may lead to an acute phase (adrenal crisis) characterized by circulatory shock
  19. 5.5 Hyposecretion of thyroid hormone during early development.
    Cretinism - Congenital condition characterized by dwarfism, retarded mental development, facial puffiness, dry skin, umbilical hernia, lack of muscle coordination.
  20. 5.6 Hypersecretion of GH before age 25 years.
    Gigantism - Condition characterized by extreme skeletal size caused by excess protein anabolism during skeletal development.
  21. 5.7 Hyposecretion of GH before age 25 years.
    Pituitary Dwarfism - Condition characterized by reduced skeletal size caused by decreased protein anabolism during skeletal development.
  22. 5.8 Temporary decrease in blood levels of insulin during pregnancy.
    Gestational diabetes mellitus (GDM) - Carbohydrate-metabolism disorder occurring in some pregnant women; characterized by polydipsia, polyuria, overeating, weight loss, fatigue, irritability
  23. 5.9 Hyposecretion of insulin.
    Type 1 diabetes mellitus - Inherited condition with sudden childhood onset characterized by polydipsia, polyuria overeating, weight loss, fatigue, and irritability, resulting from the inability of cells to secure and metabolize carbohydrates
  24. 5.10 Insensitivity of target cells to insulin.
    Type 2 diabetes mellitus - Carbohydrate-metabolism disorder with slow adulthood onset thought to be caused by a combination of genetic and environmental factors and characterized by polydipsia polyuria overeating, weight loss, fatigue, irritability
  25. 5.11 Hyposecretion of (or insensitivity to) antidiuretic hormone (ADH).
    Diabetes Insipidus - Metabolic disorder characterized by extreme polyuria (excessive urination) and polydipsia (excessive thirst) because of a decrease in the kidney's retention of water.
  26. 6. Describe the pituitary gland; the unique features of both portions: anterior pituitary and posterior pituitary and the respective hormones released or produced.
    If the Hypothalamus is the “King”, then the adenohypophysis is the “Queen” (Master Gland).

    • The anterior, or adenohypophysis, which creates & secretes:
      • Somatotrophs — secrete growth hormone (GH), which induces the liver and other tissues to produce insulin-like growth factor 1 (IGF-1) → produces most of the effects attributed to GH.
      • Corticotrophs - secrete adrenocorticotropic hormone (ACTH) → growth & secretion from adrenal cortex.
      • Thyrotrophs - secrete thyroid-stimulating hormone (TSH) → growth & secretion from thyroid.
      • Lactotrophs—secrete prolactin (PRL) → lactation.
      • Gonadotrophs—secrete luteinizing hormone (LH) [stimulates the corpus luteum of the ovary to secrete progesterone and estrogens] and follicle-stimulating hormone (FSH) [has a sexual function for male and female].
    • The posterior, or neurohypophysis, which stores & secretes:
      • Antidiuretic hormone (ADH) [prevents large urine volume]
      • Oxytocin (OT) [uterine contraction and milk ejection from the breasts]
  27. 7. Know the thyroid gland and the main hormones secreted by it.
    Thyroxin - is release in two forms: Thyroxine (T4) and Triiodothyronine (T3).

    → Although about 20 times more T4 is released than T3, T4 is essentially impotent because it binds so strongly to plasma globulins for transport in the blood that it is not taken into target tissues, and when it does, it is usually converted to T3.

    → Thyroxine (T4) has 4 iodine atoms and Triiodothyronine (T3) has 3. TH increases the body’s rate of metabolism.

    Calcitonin increases calcium storage in bone, lowering blood Ca++ levels. It opposes PTH, which has the opposite effect: decreases calcium storage in bone, raising blood Ca++ levels.
  28. 8. Know the parathyroid gland and the main hormones secreted by it.
    PTH opposes effect of Calcitonin from the thyroid, that is it raises blood Ca++ levels. It does this through the bones and the kidneys, but with greater effect through its action on bone. It causes less new bone to be formed (diminishes osteoblasts), and causes more old bone to be dissolved (increases osteoclasts), with the net effect of more calcium and phosphate entering the blood. (Ostocytes are bone cells.)

    PTH causes the kidneys to reabsorb Ca++ from the urine, but excrete phosphates.

    PTH also increases the absorption of Ca++ from food by activating vitamin D in the kidneys.

    High levels of Ca++ in the blood will inhibit the release of PTH.
  29. 9. Know the role of the Parathyroid hormone (PTH) in regulation of the calcium level in the blood.
    • Low blood Ca++ → the parathyroid increases the release of PTH, which:
      1. Causes less new bone to be formed (diminishes osteoblasts), and causes more old bone to be dissolved (increases osteoclasts), with the net effect of more calcium and phosphate entering the blood. (Ostocytes are bone cells.)
      2. Causes the kidneys to reabsorb Ca++ from the urine, but excrete phosphates.
      3. Causes an increase in the absorption of Ca++ from food by activating vitamin D in the kidneys.
    • High blood Ca++ → the parathyroid decreasing the release of PTH.
  30. 10.1 Describe the adrenal gland - Cortex, the portions as well as the hormones produced.
    The “suprarenal” glands have an outer cortex of 3 layers and an inner medulla (which is physiologically a different gland).

    → There is no communication between them.

    • Deep to the outer capsule are these 3 layers:
      • Zona Glomerulosa - secretes Aldosterone which targets kidneys to Stimulate kidney tubules to conserve sodium, which in turn triggers the release of ADH and the resulting conservation of water by the kidney.
      • Zona Fasciculata - secretes Cortisol (hydrocortisone) which targets general tissue to influences metabolism of food molecules; in large amounts, it has anti-inflammatory effect.
      • Zona Reticularis - secretes Adrenal androgens and estrogens which target Sex organs, other effectors: Exact role of androgens uncertain but may support sexual function. Estrogens are thought to be insignificant.
  31. 10.2 Describe the adrenal gland – Medulla and the hormones produced.
    • The adrenal medulla is composed of neurosecretory tissue, that is, tissue composed of neurons adapted to secrete their products into the blood rather than across a synapse. When the sympathetic nervous system is activated (as in the stress response), the medullary cells secrete their hormones directly into the blood.
    • The adrenal medulla secretes two important hormones, both of which are in the class of nonsteroid hormones called catecholamines. Epinephrine (Epi), or adrenaline, accounts for about 80% of the medulla's secretion. The other 20% is norepinephrine (NE or NR).
  32. 11.1 Describe characteristics of the mechanism of action of mineralocorticoids.
      • Mineralocorticoids, of which aldosterone being the only physiologically important human example, have an important role in how mineral salts (electrolytes) are processed in the body.
      • Aldosterone is not under the control of the adenohypophysis or hypothalamus.
      • It is under a negative feedback control system that starts with BP as seen at the juxtaglomerular apparatus
      • It primarily controls sodium homeostasis, but also has an effect on potassium and pH blood levels.
      • Aldosterone secretion is controlled mainly by the renin-angiotensin-aldosterone system (RAAS) and by blood potassium concentration.
  33. 11.2 Be able to describe how mineralocorticoids secretion is controlled.
      1. When the incoming blood pressure in the kidneys drops below a certain level, the juxtaglomerular apparatus secretes renin into the blood.
      2. Renin, an enzyme, causes angiotensinogen (a normal constituent of blood) to be converted to angiotensin I.
      3. Angiotensin I circulates to the lungs, where angiotensin-converting enzyme (ACE) in the capillaries split the molecule, forming angiotensin II.
      4. Angiotensin II circulates to the adrenal cortex, where it stimulates the secretion of aldosterone from the zona glomerulosa. (Some aldosterone is also synthesized in the heart and blood vessels.)
      5. Aldosterone causes increased reabsorption of sodium.
      6. The higher Sodium concentration increases the osmotic pressure of the blood, which is detected by osmoreceptors near the supraoptic nerves in the hypothalamus, which triggers the neurohypophysis to releases ADH, which causes increased water retention.
      7. As water is retained, the volume of blood increases. The increased volume of blood creates higher blood pressure — which then causes the renin-angiotensin-aldosterone system to stop.
  34. 12.1 Myxedema:
    Severe form of adult hypothyroidism characterized by edema of the face and extremities- often progressing to coma and death.
  35. 12.2 Cushing's syndrome:
    → Hypersecretion (or injection) of glucocorticoids RESUTING IN Metabolic disorder characterized by fat deposits on upper back, striated pad of fat on chest and abdomen, rounded "moon" face, muscular atrophy, edema, hypokalemia (low blood potassium level), possible abnormal skin pigmentation.

    → Caused by Cushing disease, which results from a adenoma (benign epithelial tumor) of the adenohypophysis causing a hypersecretion of ACTH.
  36. 12.3 Acromegaly:
    Hypersecretion of growth hormone (GH) during adulthood RESULTING IN Chronic metabolic disorder characterized by gradual enlargement or elongation of facial bones and extremities.
  37. 12.4 Aldosterone:
    The Zona Glomerulosa of the adrenal cortex secretes Aldosterone which targets kidneys to Stimulate kidney tubules to conserve sodium, which in turn triggers the release of ADH and the resulting conservation of water by the kidney.
  38. 12.5 Diabetes Insipidus:
    Hyposecretion of (or insensitivity to) antidiuretic hormone (ADH) RESULTING IN Metabolic disorder characterized by extreme polyuria (excessive urination) and polydipsia (excessive thirst) because of a decrease in the kidney's retention of water.
  39. 12.6 Goiter (simple):
    Lack of iodine in diet RESULTING IN Enlargement of thyroid tissue from the inability of the thyroid to make thyroid hormone because of a lack of iodine; a positive feedback situation develops in which low thyroid hormone levels trigger hypersecretion of thyroid-stimulating hormone (TSH) by pituitary—which stimulates thyroid growth.
  40. 12.7 Chorionic gonadotropins:
    Chorionic because the hormone is secreted by the chorion, a fetal tissue component of the placenta. It promotes the maintenance of the corpus luteum during the beginning of pregnancy, causing it to secrete the hormone progesterone.

    Progesterone, along with inhibin, suppress FSH secretion which prevents the continued development of new follicles during the functional life of the corpus luteum.
  41. 12.8 Labor:
    Oxytocin (meaning “swift childbirth”), it targets the uterus and mammary glands, causing uterine contractions and milk ejection. It is secreted by the neurohypophysis.
  42. 12.9 Grave's disease:
    Hypersecretion of thyroid hormone RESULTING IN Inherited, possibly autoimmune disease characterized by hyperthyroidism, exophthalmos (protruding eyes).
  43. 12.10 Somatotropic hormone:
    Or STH, is another name for Growth Hormone (GH), it is one of the 5 classes (Somatotrophs) of hormones secreted by the adenohypophysis. It promotes growth by stimulating protein anabolism and fat mobilization.
  44. 12.11 Diabetes mellitus:
    • Diabetes mellitus can be caused by three distinct conditions, all based on hyposecretion of insulin OR target cell insensitivity to it:
      • Childhood or type 1, hyposecretion of insulin
      • Adult onset or type 2, target cell insensitivity to insulin.
      • Gestational diabetes mellitus (GDM), it is a temporary decrease in blood levels of insulin during pregnancy RESULTING IN Carbohydrate-metabolism disorder occurring in some pregnant women; characterized by polydipsia, polyuria, overeating, weight loss, fatigue, irritability.
  45. 13. Describe the pancreas gland, the hormones secreted and their mechanism of action.
      • Alpha cells secrete Glucagon, which causes hepatocytes to convert stored glycogen to glucose for release into the blood.
      • Beta cells secrete Insulin, which promotes metabolism within cells and takes glucose out of the blood to do so.
      • Delta cells secrete Somatostatin (SS), which regulates food absorption.
  46. 14. Know the characteristics of prostaglandins.
    → Prostaglandins are a group of lipid molecules that serve important and widespread integrative functions in the body but do not meet the usual definition of a hormone.

    → Although prostaglandins may be secreted directly into the bloodstream, they are rapidly metabolized, so that circulating levels are extremely low.

    → The term tissue hormone is appropriate because the secretion is produced in a tissue and diffuses only a short distance to other cells within the same tissue. Whereas typical hormones integrate activities of widely separated organs, prostaglandins tend to integrate activities of neighboring cells.

    → There are at least 16 different prostaglandins, falling into nine structural classes—prostaglandin A through prostaglandin I.

    • Differentiation of endocrine (blood traveling hormones) from “local” or tissue hormones can be further refine by:
      • Paracrine hormones – that regulate activity in nearby cells within the same tissue as their source.
      • Autocrine hormones – that regulate activity in the secreting cell itself.
    • In addition to prostaglandins, which have diverse local (paracrine/autocrine) effects such as inflammation and muscle contraction in blood vessels, there are:
      • Thromboxane, a blood regulator important in blood clotting.
      • Leukotrienes, which are regulators of immunity.
  47. 14.1 Why do prostaglandins offer such an important clinical opportunity?
    They are likely to play increasingly important roles in the treatment of such diverse conditions as hypertension, coronary thrombosis, asthma, and ulcers because they are found in almost every body tissue and are capable of regulating hormone activity on the cellular level.
  48. 15. Describe the hormones of the gonads (testes and ovaries).
      • Adrenal Androgens and Estrogens are secreted from the Zona Reticularis.
      • Testes secrete Testosterone (small amounts from Adrenal and Ovary), which stimulates sperm production, male sexual characteristics and muscle growth.
      • Ovaries & placenta secrete Estrogen (including estradiol (E2) and estrone) and Progesterone for: growth of uterus; egg maturation and secondary sex characteristics.
      • These also cause the epiphysis (long bones) to fill with calcium terminating female growth.
  49. 16. Be able to tell the characteristics of anabolic steroids, as well as their side effects.
    They stimulate the “anabolism” building of proteins in muscle and bone.

    • On the down-side they lead to:
      • kidney disease
      • fluid retention
      • reduced testicular size
      • low sperm count
      • impotency
      • liver disfunction
      • balding
  50. 17. Know the distribution of body fluids in male/female; main divisions ICF/ECF/transcellular fluid and their subdivisions.
      • Fluids account for 40%-60% of total body weight.
      • Males @ 63% and females at 52% due to more fat. Fat contains the least amount of water of any tissue type including bone.
      • ICF has two-thirds of the water (40% of body weight for a male – 2/3 * 60%)
      • ECF has the remaining one-third of the water (20% of body weight for a male – 1/3 * 60%)
    • The ECF can be broken down as:
      • 1/2 ISF
      • 1/4 plasma
      • 1/8 transcellular fluid
        • CSF
        • Stomach
        • mucus
        • Humoral
        • joint
        • exocrine saliva
      • 1/8 lymph
  51. 18. Describe water balance, regulation of water intake and regulation of water output.
    • Water is derived:
      • 60% drinking
      • 30% moist foods
      • 10% metabolism from the production of ATP, which yields water and CO2
    • → Thirst is the primary regulator of water intake, which is affected by osmotic pressure of ECF & thirst center of the hypothalamus.

    → Distention of the stomach curbs thirst.

    → Regulator of water output: ADH affecting the DCT and CD of the kidneys.
  52. 19. Describe the electrolyte, regulation of intake and output.
    • IN: Food & drink
    • OUT: sweat, feces, urine
    • Cations: Na+, Ca+, K+, Aldosterone.
    • Note: K+ is secreted when Na+ is reserved.
  53. 20. Know the main cations and anions in the extracellular fluid,
    • Major: Na+, Cl-, bicarbonate (HCO3-).
    • Minor: K+, Mg++, Ca++, Phosphate (HPO4-2), Sulfate (SO4-2).
  54. 21. Know the main cations and anions in the intracellular fluid.
    Major: K+, Phosphate (HPO4-2), Mg++

    Minor: Na+, Cl-, bicarbonate (HCO3-)
  55. 22. Know the acid base balance. Be able to tell what happens when blood pH is above or below its normal range.
    • 7.35 – 7.45 normal pH
    • 7.3 – rapid breathing to expel CO2, which reduces the amount available to make carbonic acid or H2CO3
    • 7.2 – fatigue
    • 7.1 – vasodilation; irregular pulse
    • 7.0 – decreased consciousness
    • 6.8 – DEATH
    • 7.5 – breathing slow to keep CO2, increasing the amount available to make carbonic acid or H2CO3
    • 7.6 – muscle cramps
    • 7.7 - seizures; tetany
    • 7.8 – DEATH
  56. 23. Know which is the most acidic substance in our body.
    Stomach acid: HCl @ pH = 1
  57. 24. Know the mechanisms involved in regulation of H ion concentration.
    • → Chemical buffer (Acid base) systems – immediate
      • Bicarbonate
      • Phosphate
      • Protein
    • → Respiratory response system, one of the Physiological buffer systems – minutes

    → Renal response system, one of the Physiological buffer systems – hours
  58. 25. Know the types of buffer systems and how do they work.
    → Chemical buffer systems can combine with a strong acid or alkali and convert it to a weaker one.

    → Though their action is immediate, they can minimize a pH change, but not prevent it.

    → Most chemical buffer systems consist of “buffer pairs”, most often a weak acid and a salt of that acid.

    • These are the main chemical buffer systems:
      • Protein Buffer System – works IN/OUT of cells
      • Phosphate Buffer System - works INSIDE cells only
      • Bicarbonate Buffer System – works IN/OUT of cells.
    • Physiological Buffer Systems are activated within 1-2 minutes of the failure of the Chemical Buffer System. Initially, the Respiratory correction system will go into action. If it also fails, then within 24 hours the Renal Correction System will excrete appropriate substances.
  59. 26. Describe the role of pulmonary and renal systems as buffers in regulation of acid-base balance.
      • The first line of defense after the chemical buffer systems is the pulmonary (respiratory) physiological buffer system, which can regulate the amount of CO2 in the blood.
      • The availability of CO2 can increase/decrease the right-side components of the following reaction:
      • CO2 + H2O (via carbonic anhydrase) H2CO3 (carbonic acid) → H+ + HCO3- (bicarbonate)
      • The Renal buffer systems acts as a backup to the Respiratory Buffer System and can excrete more or less H+ as needed.
      • Note: DCT can reabsorb 95% of bicarbonate (HCO3-).
  60. 27. Know the relationship between hyperventilation and respiratory alkalosis, as well as hypoventilation and respiratory acidosis.
    • One leads to the other. That is:
      • Hyperventilation → respiratory alkalosis.
      • hypoventilation → respiratory acidosis.
  61. 28. Be able to tell the difference between a vegetarian diet and a meat-based diet, what state do they produce: alkaline or acidic?
    • Vegetarian → Alkaline
    • Meat-eater → Acidic
  62. 29. Know the definitions of the conditions: acidemia and acidosis, alkalemia and alkalosis.
    • Acidemia is caused by acidosis.
    • Alkalemia is caused by alkalosis.
  63. 30. Be able to tell the difference between metabolic acidosis and alkalosis compared to respiratory acidosis and alkalosis.
    • Normal pH: 7.4 +/- 0.05
    • Normal PCO2: 40 +/- 5
    • Normal HCO3-: 24 +/- 2

    • Respiratory Acidosis
      • Very low pH, e.g. 7.2 v 7.4
      • Higher than normal PCO2, e.g. 60 v 40
      • Normal concentration of HCO3-, e.g. 24
    • Respiratory Alkalosis
      • Very high pH, e.g. 7.58 v 7.4
      • Lower than normal PCO2, e.g. 27 v 40
      • Normal concentration of HCO3-, e.g. 24
    • Metabolic Acidosis
      • Very low pH, e.g. 7.2 v 7.4
      • Normal PCO2, e.g. 42 v 40
      • Lower than normal concentration of HCO3-, e.g. 12
    • Metabolic Alkalosis
      • Very high pH, e.g. 7.6 v 7.4
      • Normal PCO2, e.g. 40 v 40
      • Higher than normal concentration of HCO3-, e.g. 39
  64. 31. Be able to tell the different types of metabolic acidosis.
    • Diarrhea
    • Excess alcohol
    • Starvation (anaerobic metabolism → ketones)
    • Untreated diabetes mellitus (ketoacidosis)
  65. 32. Know the mechanism of metabolic alkalosis, the causes.
    • Vomiting (losing HCl)
    • Eating too many antacids (bicarbonates)
    • Constipation (decreased loss of HCO3- in feces.)
  66. 33. Know the mechanism of the excretion of the most of H+ in the form of ammonium (NH4+) and the factors, which accelerate the renal tubule excretion of ammonia.
    Increases in CO2 and H2CO3 → kidney secretion of H+
  67. 34.1 Extracellular
    Space outside the cell
  68. 34.2 Edema
    Accumulation of fluid within a tissue, as in inflammation.
  69. 34.3 Hypocalcemia
    Abnormally low calcium levels on the blood.
  70. 34.4 Intracellular
    Space within cells wall.
  71. 34.5 Hypokalemia
    Abnormally low serum potassium level.
  72. 34.6 Hypervolemia
    Abnormally increased blood volume.
  73. 34.7 Dehydration
    Abnormal loss of fluid from the body’s internal environment.
  74. 34.8 Interstitial
    In between cells.
  75. 34.9 Buffer System
    They can resist or correct, but not prevent, change.
  76. 29-1. Organic substances with the type of bond that does not permit the compound to break up in a solution are called:
  77. 29-2. Functionally, the total body water can be subdivided into the:
    Intracellular and extracellular fluid compartments
  78. 29-3. The cardinal principle about fluid balance is that it can be maintained only if intake equals:
  79. 29-4. The mechanism that tends to restore normal extracellular fluid volume when it decreases below normal is:
    Aldosterone mechanism
  80. 29-5. What two factors together determine urine volume?
    Glomerular filtration and rate of water reabsorption
  81. 29-6. According to Starling's law of the capillaries, the control mechanism for water exchange between plasma and interstitial fluid consists of all of the following pressures:
    • A. blood hydrostatic
    • B. colloid osmotic (on both sides of the capillary)
    • C. interstitial fluid hydrostatic
  82. 29-7. The mechanism of edema formation can be initiated by a decrease in blood protein concentration and, therefore, in _____ pressure.
    Blood colloid osmotic
  83. 29-8. The ADH mechanism helps maintain homeostasis of extracellular colloid osmotic pressure by regulating volume and thereby its _____ concentration.
  84. 29-9. Abnormally excessive water losses constitute a volume deficit and can lead to a state of dehydration or:
  85. 29-10. A common type of electrolyte imbalance in which potassium is lost from the body, resulting in a serum potassium level below 3.5 mEq/L, is:
  86. 30-1. Which of the following symbols is used to represent the negative logarithm of the number of hydrogen ions present in 1 liter of a solution?
  87. 30-2. Although both acid and base components are important, the homeostasis of body pH largely depends on the control of _____ ion concentration in the _____ fluid.
    Hydroxyl; extracellular
  88. 30-3. All of the following are acidic ketone bodies that accumulate during the incomplete breakdown of fats:
    • NOT phosphorus
    • Acetone
    • Acetoacetic acid
    • Beta-hydroxybutyric acid
  89. 30-4. The two major types of control systems that operate to maintain the constancy of pH are:
    Chemical and physiological
  90. 30-5. A _____ is a substance that prevents marked changes in the pH of a solution when an acid or base is added.
  91. 30-6. The process of exchanging a bicarbonate ion formed in the red blood cell with a chloride ion from the plasma is called:
    Chloride shift
  92. 30-7. Normal blood pH and acid-base balance depend on the ratio of base bicarbonate to carbonic acid buffer pair being _____ in the extracellular fluid.
  93. 30-8. A decrease in blood pH below normal (acidosis) tends to:
    Stimulate increased respirations
  94. 30-9. When blood hydrogen ion concentration increases, the distal tubules in the kidneys secrete more:
  95. 30-10. Clinical conditions such as pneumonia and emphysema tend to cause retention of _____ in the blood.
    Carbon dioxide
  96. 16-1. In the endocrine system, secreting cells send hormones to signal specific:
    Target cells
  97. 16-2. Hormones can be classified as either:
    Steroid or nonsteroid
  98. 16-3. In _____, one hormone produces the opposite effect of another hormone.
  99. 16-4. Unused hormones are?
    Usually quickly excreted by the kidneys
  100. 16-5. Because steroid hormone receptors are not attached to the plasma membrane but seem to move freely in the nucleoplasm, this model of hormone action has been called the _____ hypothesis.
  101. 16-6. The control of hormonal secretion is usually part of a (an):
    Negative feedback loop
  102. 16-7. _____ is a lipid molecule that has many functions and is rapidly metabolized so that circulating levels are extremely low.
  103. 16-8. The adenohypophysis is divided into which two parts?
    Pars anterior and pars intermedia
  104. 16-9. The stem-like stalk that connects the pituitary gland to the hypothalamus is the:
  105. 16-10. Which hormone develops the breasts during pregnancy in anticipation of milk secretion?
  106. 16-11. The formation and activity of the corpus luteum is a result of the secretion of:
    Luteinizing hormone
  107. 16-12. Antidiuretic hormone and oxytocin are stored and released by the:
  108. 16-13. The body's "biological clock" is supported by the:
    Pineal gland
  109. 16-14. Which hormone increases calcium storage in bone?
    Calcitonin (it is opposed by PTH.)
  110. 16-15. The primary function of aldosterone is:
    Sodium homeostasis
  111. 16-16. _____ accelerate(s) the breakdown of proteins into amino acids.
  112. 16-17. Which pancreatic hormone tends to promote the movement of glucose, amino acids, and fatty acids out of the blood and into the tissue cells?
  113. 16-18. The _____ serves as a temporary endocrine gland and produces human chorionic gonadotropin hormone.
Card Set
LEC 4 Exam.txt