anatomy lecture 11 supp

• gastrin secreted in response to

  distension of stomach

  change in pH

  AcH release (parasympathetic neurons)
• Gastrin causes:

  increases gastric juices

  strengthens lower esophageal sphincter contractions

  increases the motility of stomach

  relaxes pyloric sphincter
• gastrin = hormone responsible for promoting the release of pepsinogen, mucous, and hydrochloric acid in the stomach, and the presence of food or rising pH causes release of gastrin (from enteroendocrine cells)
• gastrin causes stomach glands to produce

  • hydrochloric acid
  • mucus
  • protein-digesting enzymes (chief cells)
• Acidic pH: activated pepsinogen conversion to pepsin = partial protein digestion
• acidic pH: activates pepsinogen conversion to pepsin = partial protein digestion

  • provides hostile environment for microorganisms
  • HCI partially denatures proteins
  • which stimulates the secretion of bile and pancreatic juice
• stomach:

  • The presence of food / changing acidity causes enteroendocrine cells to release hormones such as gastrin
  • this causes stomach glands to produce 1. hydrochloric acid, 2. mucus, 3. protein - digesting enzymes
• parietal cell

  • one of the cells that are the source of the hydrochloric acid and most of the water in the stomach juices
• pariteal cells

  • secrete hydrochloric acid and intrinsic factor
• in the stomach:

  • HCI creates high acidity (pH about 2) and activates the protein digesting enzyme, pepsin
  • acidity kills ingested bacteria
  • intrinsic factor is for the absorption of vitamin B12 in the small intestine
• what is an intrinsic factor?

  glycoprotein produced by the parietal cells located at the gastric body,

  this mother fuckers role is in the transportation and absorption of the micronutrient vitamin B12
• chief cells secrete pepsinogen (an inactive form of pepsin)

  • parietal cells secrete HCL to make acidic environment and in turn, HCL converts the pepsinogen to the active form of pepsin
  • pepsin helps in the digestion of proteins by breaking down polypeptides into smaller peptides
• small intestine: secretion is synthesized and secreted by S cells in the small intestine
• secretion release in mainly stimulated by gastric acid delivered into the duodenal lumen
• small intestine

  • secretin from S cells - in response to acidic chyme entering duodenum and partially digested nutrients
• left off slide 5/19
• the small intestine contains secretin

  • this is in response to acidic chyme entering the duodenum
  • stimulates the flow of pancreatic juice to help buffer gastric juice
  • increases bile production ( acts as a fat emulsifier (substance mixer) like oil and water
  • this hormone has an inhibitory effect on the gastric secretion
• what are the 3 gastric inhibitory hormones?

  • Cholecystokinin (CCK)
  • secretin
  • gastric inhibitory peptide (GIP)
• in response to partially digested proteins and fats, Cholecystokinin:

  • increases pancreatic juice
  • increases bile secretion
  • relaxes hepatopancreatic ampulla
  • contracts pyloric sphincter
  • inhibit gastric activity
• what is hepatopancreatic ampulla?


  spherical structure located on the common bile duct and pancreatic duct, and is the entry point of bile into the second portion of the duodenum
• pyloric sphincter: where the pylorus meets the duodenum

  
• gastric inhibitory peptide (GIP): Released by k cells into small intestine in response to distention of the duodenum

  • inhibits secretion of gastric juice
  • stimulates insulin release
• this mother fucker is a frame of reference summary

  
• another mother fuckign frame of reference summary

  
• kidneys:

  • stimulates the production of RBS at red bone marrow in response to hypoxia (more red blood cells = more red blood cell oxygen carry capacity)

  • also stimulates calcitriol (actives vitamin D and makes it usable and easy to absorb)
  • stimulates renin (to cut the shit out of angiotensinogen)
• erythropoietin released due to the detection of low blood oxygen

  then bone marrow is stimulated for RBCs making

  then blood Oxygen increases

  therefore decreasing initial hypoxia stimulus
• aldosterone holds onto : Na

  ADH: prevents loss of H2O (decreases urination)
• pituitary gland:

  1. posterior lobe - oxytocin and ADH
  2. anterior lobe - growth hormone, prolactin, follicle-stimulating hormone, luteinizing hormone, thyroid stimulating hormone, adrenocorticotropic hormone
• what does oxytocin do?

  • peptide
  • stimulated contraction of the uterus and the milk "let down" reflex
  • regulated by the nervous system (hypothalamus in response to uterine stretching and or suckling of baby
• what does antidiuretic hormone do?


  • peptide
  • promotes retention of water by kidneys
  • regulated by hypothalamus in response to water/ salt imbalance
• what does growth hormone do?

  • protein
  • stimulated growth, especially of bones and muscles and stimulates metabolism
  • regulated by hypothalamus releasing and inhibiting hormones
• what does luteinizing hormone do?

  • protein
  • stimulated ovaries and testes
  • hypothalamic hormone
• what does thyroid-stimulating hormone do?

  • protein
  • stimulates thyroid gland
  • thyroxine in blood, hypothalamic hormones
• what does adrenocorticotropic hormone do?

  • protein
  • stimulates adrenal glands to secrete glucocorticoids
  • regulated by glucocorticoids, hypothalamic hormones
• what does melatonin do?

  • amine
  • involved in biological rhythms (daily and seasonal)
  • regulated by light and dark cycles
  • gland = pineal gland - not anterior lobe of pituitary gland
• what does thyroxine do? (from the thyroid gland)

  • amine
  • stimulates metabolism
  • regulated by TSH (thyroid stimulating hormone)
• what does calcitonin do? (from the thyroid gland)

  • peptide
  • reduces blood calcium ion level
  • regulated by calcium ion level in blood
• what does parathyroid hormone (PTH) do? (from the parathyroid gland)

  • peptide
• what does the thymosin hormone do? (from the thymus gland)

  • peptide
  • programs T lymphocytes
• what does EPI AND NE hormone do? (from adrenal medulla gland)

  • amines
  • raise blood glucose level, increase rate of metabolism, constrict certain blood vessels
  • regulated by the nervous system