FINAL EXAM STUDYING

• Water soluble means that it is a peptide hormone, it binds to the cell surface receptor, stimulates a second messenger and produces an enzyme, this enzyme can alter the structure/function of an existing hormone = it is a quick response meaning the cell responds in seconds
• A steroid hormone means that it diffuses straight through the cell membrane, binds to a steroid hormone receptor, goes into the cell nucleus, binds to DNA/RNA and changes the gene expression. It can last days, weeks, months or even years by increasing or decreasing the production of specific genes
• Follicle stimulating hormone

  @ testes, stimulates sperm maturation
• Luteinizing hormone

  @ testes, stimulates secretion testosterone
• Adrenocorticotropic hormone

  @ adrenal cortex, stimulates secretion of its hormones
• Thyroid Hormone

  @ thyroid gland, stimulates secretion of thyroid hormone
• Melanocyte hormone

  @ skin, helps darken skin pigmentation
• Prolactin hormone

  @ mammary glands, stimulates milk production and secretion of milk
• Growth hormone

  @ cartilage, bones, SKM, liver, it increases human body growth and secretion of other hormones
• Tropic effect

  stimulates the release of another hormone
• Trophic effect

  nourishing effect, it helps support the hormone that was just released
• What is the purpose of negative feedback regulation?

  Homeostasis, it counteracts and ensures that it is kept at a narrow bodily range
• Thyroid Hormone (T3 and T4)


  they come from tyrosine, an amino acid + iodine
• Hypothyroidism

  dwarfism or severe myxedema, slows heart rate, muscle weakness, cold sensitivity
• Grave's Disease

  autoimmune, your body makes antibodies that mimic TSH and bind to the TSH receptor causing hypersecretion
• Hashimoto's disease

  hypo-secretion, kills follicular cells, causing inflammation
• Glucocorticoids

  ACTH = ZF cells = glucocorticoids (cortosiol)

  helps regulate the body during stress, increase protein catabolism and lipolysis, increase gluconeogenesis, overall increases stress resistance due to increasing nutrient availability, increase BP by adrenergic receptors
• Mineralcorticoids

  @ zona glomerulosa, stimulated by Ang 2, high K levels, low NA, aldosterone, increase absorption at GI tract, increase kidney reabsorption so water follows
• Androgens (DHEA)

  sympathetic NS target chromaffin cells, produce and cause release of NE/E, very low levels in males, high in females and contributes to sex drive

  DHEA = testosterone and estrogen
• Insulin

  HYPERGLYCEMIA, stimulated by beta cells, produce insulin, causing increase glucose uptake, increase amino acid uptake and protein synthesis, overall decrease blood glucose
• Glucagon

  HYPOGLYCEMIA, stimulated by alpha cells, produce glucose, increase glycogenolysis and gluconeogenesis, overall increase blood glucose
• what is mobility in the GI tract

  movements of the tube, mediated by SM = autorhythmic
• what is secretion at the gi tract

  adding stuff to the tube = largely composed of enzymes, other large chemicals aid in digestion and water
• what is digestion at the gi tract

  overall process of breaking down foods either by chemical or mechanical digestion
• what is absorption at GI tract

  the process of taking the broken down substances into the body, dependent on substances and nutrients that are absorbed
• three major glands that secrete saliva

  parotid gland, submandibular gland, sublingual gland
• composition of saliva

  enzymes, mucus, water, HCO3-, lysosomes
• function of saliva

  cleanses the mouth, dissolves chemicals for taste, moistens food and then compacts it into a bolus
• Function of the SM in gi tract

  auto-rhythmic, has both electrical and mechanical coupling, basal tone for constant slight contraction because digestion can take hours
• parietal cells

  @ stomach, secrete hydrochloric acid and intrinsic factor
• chief cells

  @ stomach, secrete pepsinogen and gastric lipase
• K cells

  @ si, secrete gastric inhibitory peptide (GLP1), stimulates the pancreas to produce insulin and promotes storage of fat, decreases appetite
• L cells

  @ si, secrete gastric inhibitory peptide (GLP1), stimulates pancreas to produce insulin, decreases gi mobility, slows emptying thus making you feel full, release bicarb = increase intestinal PH
• S cells

  @ si, secrete secretin, stimulates pancreatic ductal cells to secrete bicarb to pancreas, helps control PH of chyme entering SI so its not too acidic, stimulates production of bile by targeting liver
• CCK Cells

  @ si , release cholecystokinin, stimulates pancreatic acinar cells to 1. secrete enzymes, 2. help secretin, 3. stimulate gallbladder to release stored bile, 4. inhibits SM to slow gastric emptying and slow churning, 5. helps stimulate pyloric sphincter to slow gastric emptying
• G cells

  @ si, stimulated by an increase in PH of the stomach, stimulates g-cells in stomach walls causing the release of gastrin in parietal cell, further stimulating Ca2+ production and H+/K+atpase pump, goes to chief cells activating secondary messenger system exocytosis pepsinogen which helps with protein digestion
• how are proteins digested?

  ingested in the mouth, broken down in stomach by pepsin, in SI they are further broken down and absorbed by; trypsin and chymotrypsin, Aminopeptidase and dipeptidase (at brush border of SI)
• how are lipids digested?

  start getting broken down at the mouth via lingual lipase and into the stomach, at stomach get further broken down by gastric lipase, small intestine gets absorbed by pancreatic lipase

  always get broken down into glycerol and fatty acid
• how are starches digested?

  starts in mouth by salivary amylase, in stomach gets broken down into glucose, in si gets absorbed via Na+/glucose transporter into the blood
• functions of the liver

  detoxification of harmful substances, produces bile that breaks down fats, stores nutrients and vitamins, helps regulate BGlevels by storing excess glucose as glycogen, synthesizes lipids