Digestive System Amd Excretory System Flashcards
What is mechanical digestion
Breakdown of food into smaller pieces without chemical change to the food molecule
Chemical digestion
The breakdown of large insoluble molecules into small soluble molecules
Mouth
Mechanical digestion: teeth che food to break into smaller pieces for larger SA to volume ratio
Chemical digestion: salivary amylase break down starch
Starch —> maltose
Oesophagus
Passes blooded of food by peristalsis from mouth to stomach
Stomach
1) contract muscular walls; churn to break up the food by mechanical digestion
2) produces protease enzyme for breakdown protein
3) produces HCl - maintain pH level for enzyme action and kills bacteria by acidic conditions which denature enzyme - product amino acid
pH in stomach 2-3 acidic
Small intestine
Chemical digestion ; protease, amylase, lipase
—> pancreas secreted into small intestine
pH 8 alkaline
Lipid digestion. Starts here
Liver
Makes bile to be secreted into the small intestine
1) neutralize the acid in the stomach to provide a suitable pH to work
Neutralize acidic food from stomach
2) emulsifiers fats increasing surface area so enzyme can digest the more quickly
Ileum
Lined with villi to increase surface area which absorption can take place
1) thin walls
Speed up the rate of diffusion of molecules into the blood
2) rich blood supply
Helps carry absorbed molecules away from intestine - always low concentration of food molecules in the blood maintain high conc gradient
3) increase. Length
Increase SA
4) SURFACE area
Villi increase surface area means digested food can be absorbed into the blood stream faster
Large intestine
Indigestible food passes through large intestine consist of the colon, rectum and anus remaining salts and water are absorbed
Faecas stored in the rectum before removed
Glomerulus
Filter small solute from the blood
Proximal convuluted tubules
Reabsorb water, ion and nutrients: removes toxins and adjust filtrate pH
Descending loop of Henles
Aqua poring allows water to pass from the filtrate into the interstitial fluid
Ascending loop of henle
Reabsorb Na+ and Cl- from the filtrate into the interstitial fluid
Distal convoluted tubules
Selectively secrete and reabsorb different ions to maintain blood pH and electrolyte balance
Collecting duct
Reabsorb solutes and water from the filtrate
Removes from the blood
Most urea
Excess H2O
Excess salts
Reabsorb into the blood
All glucose
Most H2O
Some salts
Renal artery urea
More
Renal artery water
More
Renal artery salts
More
Renal artery glucose
More
Renal artery oxygen
More
Renal artery carbon dioxide
Less
Renal vein urea
Less
Renal vein water
Less
Renal vein salts
Less
Renal vein glucose
Less
Renal vein oxygen
Less
Renal vein carbon dioxide
More
Too much water cold day less sweating occurs
1) osmoreceptors @ hypothalamus detect high water potential in blood, then send nerve impulse to the pituitary glands
2) less ADH is secreted by pituitary gland
3) ADH travel through blood and reach the collecting duct
4)less water reabsorption
5) more volume of urine ( less concentrated urine )
Too little water hot day more sweating
1)Osmoreceptor @ hypothalamus detect lower water potential in the blood send the impulse to the pituitary gland
2) more ADH is secreted by pituitary gland
3)ADH travel through the blood to the collecting duct
4) more ADH —> makes more permeability of collecting duct
5) more water reabsorption
6) less Volume of urine (more concentrated urine)
Glucose and oxygen is used for excretory
For respiration
Glomerulus and capsule
1) blood is filtered in the kidney. Blood enters the renal capillaries at high pressure - filtered by the glomerulus which allows small holes to allow molecules through
From:
RBCs
WBCs
Platelets
Glucose
Amino acid
Urea
Salts
Waters
After:
Urea
Water
Salts
Glucose
Amino acid
Proximal convoluted tubules
After filtration the fluid contain lots 9 glucose and urea water and ions. This passes through the nephron, and certain molecule are reabsorbed back into the blood. The left over form our urine
- reabsorb ions water, and nutrients removes toxin and adjust filtrate pH
Reabsorb
Glucose
Amino acid
Water
Glucose is reabsorbed at the proximal convoluted tubules via active transport so it can be used for respiration
Loop of Henley
Ascending loop of henle
Reabsorb Na+ and Cl- from the filtrate interstitial fluid
Descending
Selectively secrete and absorb different ions to maintain blood pH and electrolyte balance
Reabsorb
Water
Salts
Collecting duct
Whatever is not reabsorbed is sent to the collecting duct then can pass out of the kidney as urine
Some water is also tea sorbet at the collecting duct depending permeability
Urine is made up of water, ion and urea
URINE
- urea
-excess salt
-excess water
Glomerulus
Filters the small solute from the blood
—> protein is not filtered out and remains in the blood
Proximal convoluted tubules
Reabsorbs ion, water, and nutrients: remove toxin and adjust the filtrate pH
—> 100% of the glucose read or Ed back into the blood capillaries; two-third of sodium(salt) and water reabsorb
Descending loop of henle
Aquaporin allow water to pass from the filtrate into the interstitial fluid
~ only water is reabsorbed and not sodium
Loop of henle bottom
Sodium concentration is at its highest
Ascending loop of henle
Readsorbs Na+ and Cl- from the filtrate into the interstitial fluid
Only sodium reabsorbed
Distal convoluted tubules
Selectively secrete and reabsorb differrent ions to maintain blood pH and electrolyte balance
More sodium reabsorbed
Collecting duct
Reabsorb solutes and water from the filtrate
