How to protect the internal body from pathogens?
Mucus
Gastric juice
Lymphatic and immune tissues
stomach roles
protection
storage
digestion
liters stomach can hold
hold 50mL on empty stomach but can hold up to 4-6L
folds of the stomach
rugae
stores food in the stomach
fundus
entrances to the stomach
esophageal sphincter
pyloric sphincter
layers of the stomach (inner to outter)
mucosa
submucosa
muscularis externa
-oblique muscle
-circular muscle
-longitudinal muscle
serosa
hold the abdominal viscera in their proper place and prevent tangling and provide nutrients
mesentaries
digestive processes
-ingestion
-propulsion
-digestion
-absorption
-compaction: absorbing water and putting indigestible materials into feces
-defecation- eliminating indigestible food
gastric juice and digested food mix to make
chyme
stomach secreting cells
-parietal cells: HCl and intrinsic factor
-chief: pepsinogen
-mucous neck cells: mucus
enteroendocrine cell
G cell- gastrin
stimulates parietal cells and chief cells which make gastric juice
phases of gastric regulation
-cephalic: secretion of parietal cells and G cells from the sight/smell of food
-gastric: stimulated by stretching and rising pH of the stomach
hormones: agh, histamine, gastrin
negative feedback at a low ph and positive feedback as protein is digested
-i
reflex that stops gastric secretion and which hormones are released
enterogastric reflex
secretin and CCK are released
vomiting
vagus nerve in the medulla
-increase in intra-abdominal pressure
-realxation of esophageal-cardiac sphincter
-elevation of soft palate
-closing of connection between oropharynx and nasopharynx
parts of the small intestine
duodenum
jejunum
ileum
secretin
tells hepatopancreatic sphincter not to contract so that bicarbonate and water can enter
brush border of the small intestine
brush border enzymes that digest carbohydrates and proteins
epithelium of the small intestine
absorptive cells
goblet cells
enteroendocrine cells with CCK and secretin
Valleys of the villi
crypts
secrete water and electrolytes that mix with mucus to make alkaline intestinal juice, no enzymes
liver
-hepatocytes make bile
-alkaline solution
-bile salts: emulsify fats and made of cholesterol
-functions: nutrient conversion, makes plasma proteins, storage
imbalances with liver
-hepatitis: malfunction and inflammtion of liver by viral infection
-cirrhosis- chronic hepatitis
gallbladder
-gallstones: too much cholesterol and not enough bile salts
pancreatic
-makes enzyme rich secretions
-pancreatic juice: bicarbonate and proteolytic enzymes that are activated in the duodenum (trypsinogen), lipase/nuclease/amylase- need bile to be present
-Acini contain granules with digestive enzymes
hormonal regulation
-secretin: from acid rich chyme and secretes bicarbonate and water
-CCK: from fat rich chyme and secretes pancreatic juice and bile
major sites of absorption
-duodenum and jejunum
recycling of bile salts
ileum
pepsin digestion
-pepsin breaks down proteins in stomach
-pancreatic enzymes (tryprin) break down proteins in small intestine
-brush border enzymes break down small peptides
-use cotransport with sodium to get in to the villi then go to the liver with hepatic portal vein
carbohydrate digestion
-salivary amylase in mouth
-pancreatic amylase in the small intestine
-brush boreder enzymes braking disaccharides into monosaccharides
-glucose and galactose absorbed by cotransport
-fructose is absorbed by facilitated diffusio
lipid digestion
-bile salts emulsify fats
-pancreatic lipase breaks down fats in small intestine
-fatty acids enter with simple diffusion that are coated with proteins to make chylomicrons and they enter lacteals
hormone secreted by the kidney to produce red blood cells
erythropoietin
terms for urinary
-afferent arteriole
-renal corpuscle- contains the glomerulus (capillary network)
-podocytes- cells around the capillaries of the glomerulus
-efferent arteriole
-peritubular capillaries- vasa recta
-proximal convoluted tubule- longest and most coiled
-nep
Filtration
-movement of material into capsule to form a filtrate
-body filters 180L in real corpuscle but only 1-1.5 will be excreted as urine
-renal corpuscle- has the glomerulus which is a cluster of nerves that filters blood
-highly permeable, no active transport
Reabsorption
-solutes and water are reabsorbed into the interstitial fluid and then the blood
-most takes place in the proximal convoluted tubule
-peritubular capillary is fenestrated
-reabsorption of sodium us by Na/K pump
-glucose and amino acids use symport to get
osmolality
-of blood: 300mOsms
-solutes per 1kg water
-greater osmolality the deeper the medulla
-descending nephron loop- water is released using aquaporins
-vasa recta pulls water to veins
-thin ascending limb- concentration decreases
-thick ascending arm- sodium
collecting duct
-make highly concentrated urine by reabsorbing water while wastes and NaCl pass through
dilute urine
-high blood pressure so to excrete water, collecting ducts remain impermeable to water and cannot reabsorb any
-osmolality of urine can be as low as 50msoms
reabsorbing water
-low blood volume and increased osmolality of extracellular fluid, increase water input
-osmoreceptors in thirst center of hypothalamus release ADH and then aquaporins are inserted on membrane of distal convoluted tubules and collecting duct
reabsorbing NaCl
-aldosterone is released from adrenal cortex and puts active sodium pumps in the DCTs and collecting ducts
secretion
solutes are secreted from blood into the filtrate
Glomerular filtration rate and regulation
-GFR: 180L/day
-intrinsic regulation: myogenic- afferent arteriole changine
-low BP: dilated arteriole (increased GFR)
-high BP: constricted arteriole (decreased GFR)
-extrinsic: epinephrine and by sympathetic nervous system and norepinephrine and epineph
external, internal, accessory anatomy of male
-external: scrotum, penis
-internal: testes, ducts
-accessory: seminal vesicles, prostate, bulborethral
testes
-contains seminiferous tubules for sperm production
-sertoli cells: nurse cells that provde nutrients and make blood testes barrier and secrete accessory protein
-interstitial (leydig cells) secrete testosterone
spermatogenesis:
how many days
-MEIOSIS
-spermatogonia have mitotid division at puberty into spermatogonium and primary spermatocyte
-primary spermatocyte makes two secondary spermatocytes at first meiotic division
-at second meiotic division, secondary spermatocyte makes 4 spermatids
how to become mobile
-sperm are in epididymis for 20 days to become mobile
-wait at the bottom of the epididymus to mature
-at ejaculation it leaves
path of sperm after epididymis
-vas deferens with peristalsis
-ejaculatory duct
-urethra
accessory glands that make up semen
-seminal vesicles: 65%
prostaglandins for contractions of vagina
fructose for energy of sperm
-prostate: 30%
sperm activators
clotting enzyme
buffer
-bulborethral: 5%
neutralizing mucus
hormonal regulation of male
-GnRH at puberty
-LH- stimulates Leydig cells to secrete testosterone
-FSH- secrete accessory protein to help testosterone and inhibin
erection
-parasympathetic
-dilation of arterioles
-blood filled the corpora cavernosa
-veins are closed to keep the blood inside
-viagra stimulates this
ejaculation
-bladder sphincter contracts
-rhythmic contractions of penis and propulsion of semen from urethra
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