PHYSIOLOGY And Some Schemes Of Endocrine Ca And P Phisiology Flashcards
Oral mucosa and esophagus present …. Epithelium
Stratified squamous non-keratinised
Stomach, intestine and colon present… epithelium
Columnar
Gastric glands have… cells
Principal and parietal
Duodenal glands of Brunner have…. cells
Mucinous
Intestinal crypts of lieberkuhn have… cells
Paneth
Salival glands present… cells
Acinar
Gastric secretion has the … pH
Lowest
Pancreatic secretion and Brunner glands have the … pH
Highest
Most of the secreted fluid comes from…
Stomach and Small intestine
Serous secretion is characteristic of … glands
Parotid, submaxilar and sublingual
Mucinous secretion is characteristic of … glands
Submaxilar, sublingual and bucal
Contents of serosa
Ptialine, which breaks down starch
Content of the saliva
Potassium, bicarbonate, chloride and sodium mainly
Primary secretions coming from the acinous salivary glands move through the duct where it becomes a secondary secretion:
Very rich in potassium and bicarbonate
Stimuli for acid secretion by parietal cells
Acetylcholine (released by the vagus nerve which innervates parietal cells), Gastrin (produced by G cells in the antrum), histamine (enterocromaffin-like).
Secretory cells in gastric/oxyntic glands
- Mucous or principal cells which produce MUCUS (bicarbonate)
- Parietal cells, which produce Hcl and intrinsic factor for vitamin B12
- Chief cells, which produce pepsinogen (for protein breakdown)
Pyloric or tubular glands contain endocrine cells such as…
- G cells, which release gastrin (stimulate Hcl secretion)
- D cells, which release somatostatin (inhibit Gastrin and Hcl release)
- Enterochromaffin-like cells (ECL), which release HISTAMINE
CEPHALIC PHASE OF GASTRIC SECRETION
- 30% of total Hcl secretion
- Stimuli are taste and smell
- Direct vagal stimulation or indirect (via gastrin) for Hcl release
GASTRIC PHASE OF GASTRIC SECRETION
- 60% of total Hcl secretion
- Stimuli: gastric distension, presence of peptides
- Direct or indirect (gastrin) vagal stimulation
INTESTINAL PHASE OF GASTRIC SECRETION
-10% of total Hcl secretion
- Mediated by protein digestion products.
Complete this scheme bout neuro-hormonal GI secretion
Histamine stimulus is…
GASTRIN
Histamine action in the stomach:
Increase Hcl secretion
Histamine origin
ECL cells
Gastrin origin
G cells antrum
Gastrin stimulus
Distension and proteins
Gastric actions in the stomach
Increases: emptying, Hcl secretion, Pepsin (by chief cells), and Histamine (ECL cells)
PARASYMPATHETIC actions in the stomach
Emptying, Hcl production by parietal cells, Pepsinogen production by chief cells.
Secretin stimulus
Acidity and fat
Secretin action in the stomach
Increase secretion of pepsinogen by chief cells
Somatostatin actions in the stomach
Decrease emptying and Hcl secretion
Somatostatin stimulus
Acidity
Somatostatin origin
D cells antrum
Cholecystokinin action in the stomach
Decrease emptying, increase Hcl secretion (stimulus is fat and proteins)
Cholecystokinin origin
I cells duodenum
Secretion in the duodenum is done by…
Brunner Glands
Function of Brunner glands duodenum
Secretion of alcalin mucus for protection against Hcl
Brunner glands duodenum stimuli
- touch, distension and irritants
- PS innervation (X)
- Secretin (S cells duodenum)
Secretin not only increases pepsinogen secretion but also stimulates…
Brunner glands in duodenum (for mucus production)
Inhibition Brunner glands
Stress, Sympathetic system (causing stress ulcers)
Secretion along the small inestine is carried out by…
Lieberkühn crypts at the base of the intestinal villi
Function of ENTEROCYTES in Lieberkühn crypts of small intestine
Secretion of water and electrolytes, absorption of digestion products.
Function of GLOBET CELLS in Lieberkühn crypts of small intestine
Mucus for pretectiom
Function of Paneth cells in Lieberkühn crypts of small intestine
Antimicrobial defense
Function of Stem cells in Lieberkühn crypts of small intestine
Renewing of epithelium
…. secrete enzymes such as peptidases, sacarases, maltases, lactases, intestinal lipases in the small inestine
Enterocytes
Mechanism of water secretion in Lieberkühn crypts of small inestine
Active transport of Cl- and HcO3- with passive diffusion of Na+ (water gets dragged by Na)
La diarrea en la quimio surge porque…
Mueren las stem cells at the base of small intestinal crypts
In large intestine there are… but no…
Lieberkühn crypts, intestinal villi
In large intestine there are … and …, even though they do not produce digestive enzymes as in small inestine
Goblet cells (more than in small intestine), enterocytes
Main function of large intestine
Absorption of water, electrolytes and vitamins stimulated by PS SYSTEM
Mucus functions in large intestine
Protection and feces cohesion
Secretin hormone function in the pancreas
Activates ductal cells to produce HCO3- rich fluid
Cholecystokinin function in the pancreas
Activates acinar cells to produce enzymes
Types of cells in the exocrine pancreas
Ductal: with a main pancreatic duct (Wirsung)
Acinar: secreting digestive enzymes to pancreatic ducts
Secretin action in the pancreas
Increase HCO3 in duct cells
Cholecystokinin action in the pancreas
Increase enzymatic secretion in the acinar cells
Parasympathetic action in the pancreas
Enzyme secretion by acinar cells, HCO3 secretion by ductal cells
The pancreas has 2 main functions
Digestion (acinar cells)
Hydration and alkalinization by ductal cells
Hereditary pancreatitis is usually developed because of…
Problems in the trypsin gene
In acinar secretion, …. (zymogen) is released with …
In the small intestine it is converted into … by the … (from duodenal enterocytes).
Finally, … will convert the rest of zymogens in the duodenum.
Trypsinogen, trypsin inhibitors, trypsin, enterokinase
Trypsin.
Acinar cells produce many regulatory factors such as…
Pro-colipase, trypsin inhibitors, monitor peptide.
Ductal secretions are… rich
Bicarbonate
HCO3 from ductal secretions comes from…
The production inside the cells with Carbonic anhydrase and the extraction of it from blood
Exit of Cl to the lumen in ductal secretion is done thanks to…, and its recycling by…
CFTR (the one of cystic fibrosis), Cl/HCO3- PUMP
In ductal secretion in the pancreas, the hydrogen ions exit the cell to the to the interstitium via the..
Na+/H+ exchanger
After pancreatic bicarbonate rich secretion thanks to ductal cells, …. in the lumen reacts with … from the stomach so as to neutralise the pH before pancreatic enzymes (from the acinar cells of the pancreas) become active in the small intestine.
HCO3-, Hcl
Stimuli for HCO3- secretion in ductal cells
Secretin (produced by S cells in the small intestine) and Ach from the PS system.
The gallbladder stores … produced by the liver and then releases it along with pancreatic secretions into the 2nd portion of the duodenum thought the …
Bile, Ampulla of Vater
Composition of bile
Water, bile salts, phospholipids, cholesterol, bile pigments (bilirubin), Na+, HCO3X and other electrolytes
Biliary secretion functions
Facilitates the emulsion, solubilization andabsortion of fat
Helps alcalization of the duodenal lumen
Extrection of byproducts by metabolism from the organism.
What happens in the cephalic phase of biliary secretion?
- Relaxation of the Oddi Sphincter (X)
- Bile to the duodenum before the chyme
Action of CCK (I cells duodenum) in the intestinal phase of biliary secretion
CHOLAGOGUE ACTION: contracts the gallbladder and increases the passage of bile to the duodenum
Action of secretin (S cells duodenum) in the intestinal phase of biliary secretion
CHOLETERIC ACTION: it increases the production of bile by the hepatocytes and of luid from ductal cells
Gallbladder is essential (T/F)
False: it is not essential. without it there is not bile concentration and the flux of bile is constant although it also increases with meals
Cholecystokinin and Acetylcholine of the PS NERVOUS SYSTEM cause…
Contraction of the gallbladder and relaxation of the sphincter of Oddi.
Stimuli for biliary secretion
Secondary bile acids in the intestine suffer…. so as to become bile salts
CONJUGATION
Main characteristic of bile salts that allow them to carry out fragmentation and emulsification as well as solubilisation and absorption
They are amphipatic
Free and already used bile salts diffuse into the blood and enter …
Portal circulation
… of bile acids are recycled, losing only… through the feces.
95%, 5%
Hepatic structure
Anatomical unit of the liver
Hepatic lobule
Functional unit of the liver
Hepatic acinus
Hepatic zones
ZONE 1: peripheral or porto-portal
ZONE 2: intermediate
ZONE 3: peri-central
Hepatic sinusoids have …. endothelium and have/do not have basement membrane
Fenestrated, do not have
In the space of disse we find … cells
HEPATIC STELLATE CELLS
Flow per minute reaching the liver
1. Portal vein:
2. Hepatic artery:
3. Total approx:
- 1L (75%)
- 300 ml (25%)
- 1.3L=27% of cardiac output
When do we consider there is considerable portal hypertension?
If the gradient is greater than 10mmHg (from portal vein to hepatic veins)
Main cause of liver hypertension
Liver CIRRHOSIS
Portal hypertension is usually due to LIVER CIRRHOSIS (increased fibrosis). There is resistance to portal hepatic flow and the flow finds collateral venous systems, which cause problems such as:
- ESOPHAGEAL VARICES
- SPLENOMEGALY
- ASCITES
- HYPERPLENISM (sequester platelets)
Main cell responsible for liver regeneration
Mature hepatocyte
Molecules involved in priming phase of liver regeneration
INFLAMMATORY CYTOKINES: TNFa, IL6
Molecules involved in proliferation phase of liver regeneration
GROWTH FACTORS: EGF, HGF
Molecules involved in termination phase of liver regeneration
TRANSFORMING GROWTH FACTOR: TGFb
Hepatic venous blood after liver passage is sterile because … cells purifícate bacterial products
KUPFFER CELLS
Kupfer cells enter the … through the … in response to chemokines and damage signals.
space of Disse
fenestrae of sinusoidal endothelium
Which proteins does the liver store?
A, D and B12
Hepatocytes contain large amounts of … (lo que te falta a ti)
FERRITIN
Liver is also responsible for protein production of the…
COAGULATION CASCADE
• Fibrinogen, prothrombin, Factor V (acceleratingglobulin), Factor VII, Factor IX, Factor X
• Some depend on vitamin K for their hepaticproduction: “1972” (Factor 10, 9, 7 and protromin -factor 2-)
Gluconeogenesis is increased in zone … of the liver
1 (peripheral, porto-portal)
GLYCOLISIS is increased in zone… of the liver
3 (peri-central)
Jaundice can be cause due to…
LIVER- BILIARY DISEASES (problem in excretion of conjugated bilirubin to bile duct) or HEMOLYSIS (increased unconjugated bilirubin production)
…. is absorbed by the liver and converted into …
Indirect/unconjugated, direct or conjugated
Conjugated bilirubin is excreted through the … until it reaches the intestines
Bile duct
Conjugated bilirubin is transformed into … by intestinal microbiome
UROBILINOGEN
UROBILINOGEN is transformed into … and excreted through the feces
STERCOBILINOGEN AND STERCOBILIN
UROBILINOGEN is converted into … in the kidneys and excreted through urine
Urobilin
18% of UROBILINOGEN is reabsorbed by the intestinal walls, entering the … and being recycled (it returns to liver)
ENTEROHEPATIC CIRCULATION
The liver transforms … into … by a process known an, it is then excrete through urine
NH3, UREA, UREA CYCLE
Bilirubin detoxification scheme
Ammonia detoxification scheme
CALCIUM AND PHOSPHORUS FUNCTIONS
PROTAGONISTS IN PHOSPHO-CALCIUM METABOLISM
REGULATION OF PTH RELEASE
PTH ACTIONS AND VIT D ACTIVATION
EFFECTS OF PTH ON BONE
EFFECTS OF PTH ON KIDNEY
SYNTHESIS AND EFFECTS OF VIT D
INTESTINAL CALCIUM REABSORPTION
HORMONAL RESPONSE TO HYPOCALCEMIA
When the lower esophageal sphincter does not work properly, it is called…
ACHALASIA
Migrating motor complex is..
Small wave of contraction during fasting in small intestine which cleans dead cells, bacteria…
Carried out by MOTILIN
Liver lymphatics, lumber lymphatics and intestinal lymphatics are connected by…
CISTERNA CHYLI
The main absorption of water is done in…
COLON
Absorption of vitamins and minerals is done mainly in the….
Small intestine
Calcium and iron are mainly absorbed in the…
Duodenum
Fats and vitamins are mainly absorbed in the…
Jejunum and ileum
Vitamin B12 and bile salts are mainly absorbed in the…
Terminal ileum
…. is found in saliva and protects vitB12 from gastric digestion
HAPTOCORRIN
Vit B12 binds… and travels to Terminal Ileum
Intrinsic Factor
VitB12+Intrinsic factor enters enterocytes through…
CUBILIN RECEPTOR
Deficiency of Intrinsic Factor, CUBILIN receptor, achlorydria or resection of terminal ileum causes…
PERNICIOUS OR MEGALOBLASTIC ANEMIA (huge erythrocytes)
Treatment for pernicious/megaloblastic anemia
Give patients liver extracts (main place of storage for VitB12)
Before entering the liver, Fe3+ in transformed into Fe2+ by…
Duodenal cytochrome B
Fe2+ enters the hepatocytes by…
DMT-1 TRANSPORTER
Iron can be stored in the hepatocytes in the form of…
FERRITIN
Iron exits the hepatocytes by…
FERROPORTIN
Fe2+ is transformed into Fe3+ before entering the blood by …
HEPHAESTIN
Fe3+ joins … in blood and is transported either to the liver or to the bone marrow.
PLASMA TRANSFERIN
…. inhibits ferroportin
HEPCIDIN
Calcium absorption can be transcellular active by…
TRPV5
Calcium is sent to blood thanks to Calcium Binding Protein known as…
CALBINDIN
CALBINDIN (calcium binding protein) is increased by…
VITAMIN D
Microbiome is mostly rich in…
COLON
Microbiome produce vitamin…
K
Firmicutes like Clostridium or Lactobacillus are predominant in the…
SMALL INTESTINE
Bacterioides are predominant in the …
COLON