Bio Class 9 Flashcards
Excretory Organs
Colon
- digests solid waste
Liver
- digests hydrophobic waste (waste not absorbed or dissolved in blood)
Kidney
- digests hydrophilic waste
- deals with urine production & excretion
- BP regulation, fluid osmotic balance, pH regulation, activation of vitamin D, stimulating RBC through producing erythropoiten, filtration
Urinary Organs
Adrenal gland (found on top of kidneys) Kidney (2) Ureter Bladder Urethra
Internal vs Extern urinary sphincter
Internal
- involuntary
- smooth muscles
External
- voluntary
- skeletal muscle (striated)
Functional Unit of kidney
nephron
- has millions of nephrons
If reabsorbing water, is a shallow or deep nephron better?
Deep because it will increase in osmolarity the deeper you go into medulla
Renal pelvis
Urine is dumped
Ureter
Connects the kidney to bladder
Reabsorption vs secretion
Reabsorption
- nephron into blood
Secretion
- blood into nephron
Filtration
moving substance across membrane using pressure
Reabsorption
Moving substance from filtrate to blood
- glucose, water, amino acids are reabsorbed
- Na+, HCO3- are reabsorbed *
- K+, H+ are reabsorbed*
- depends on body’s need
Secretion
Moving substance from blood to filtrate
- drugs, toxins, creatine
- Na+, HCO3- are secreted *
- K+, H+ are secreted*
- depends on body’s need
If the body is acidic, what will it secrete? What will it absorb?
It will secrete H+ and absorb HCO3-
Creatine
Waste product from muscle metabolism
- creatine formation and secretion is constant so you can use it to measure function of kidney
What happens in the nephron?
- Blood coming into glomerulus via afferent arteriole and exits via efferent arteriole
- The blood plasma is filtered out and enters the capsule because of the pressure and is not called the filtrate
- Enters proximal convulted tubule which is the main reabsorption and secretion site, relatively unregulated
- Then enters descending loop of henle which is where water reabsorption occurs and it is impermeable to Na+; therefore osmolarity increases
- Then enters ascending loop of henle which is where Na+ reabsorption occurs and is impermeable to water so osmolarity decreases
- Then enters distal convulted tubule which is specialized reabsorption and secretion
- 2 main hormones but mostly aldosterone (which increases Na+ reabsorption and k+ secretion) - Then exits through collecting duct where ADH/vasopressin reabsorbs water
Relationship between:
urine & blood
volume and concentration
If urine volume increases, blood volume decreases BUT urine concentration decreases and blood concentration increases
Renin angiotensin system
- Angiotensinogen is a zymogen that is inactive and produced by liver
- When BP is low, kidney will release renin which activated angiotensinogen to angiotensin I
- Then you have the lungs secreting angiotensin converting enzyme which will then cause angiotensin I to make angiotensin II
- as a result you will have vessel constriction (which means BP increases) AND increase in aldosterone release (Which means more Na+ in blood = increase in ADH to have more water = more blood volume = bp increases)
Atrial natriuretic peptide/factor
Opposite of Renin angiotensin system
- High BP so atria is stretched
- RA then releases ANP
- As a result it inhibits Aldosterone release (so decreases BP) AND vessel dilation (so decreases BP) AND inhibits renin release (blocks the JGA so decreases BP)
pH regulation
Renal regulation of blood pH is slow so lungs regulate blood pH
Juxtaglomerular apparatus
contact point between afferent arteriole & distal convuluted tubule
Afferent arteriole
- baroreceptors
- release of renin if BP is low
Distal convuluted tubule
- chemoreceptors
Alimentary Canal
“GI tract”
- tube from mouth to anus
Accessory Organs
- digestive role but not part of alimentary canal
- liver, gallbladder, pancrease
Liver
produces bile & emulsifies fat
- bile itself does not digest the fat but it breaks the fat into pieces so that lipase can work on it more
Gallbladder
Stores and concentrates bile made by liver
- if you don’t have gall bladder it’s okay, it’ll just make digestion harder in the beginning but bile duct will enlarge after
Pancreas
Endocrine Role
- produces insulin and glucagon
Exocrine Role
- produces digestive enzymes
- produces bicarb (to neutralize food coming from stomach which is acidic)
Digestive enzymes
Lipases - digests lipids/fat
Amylase - digests carbohydrates, specifically starch
Protease - digests amino acids/proteins
Nuclease - digests nucleic acids
Alimentary Canal Wall
Lumen (where food is) –> mucosa (epithelial tissue) –> submucosa (connective tissue) –> circular muscle tissue (contracts to decrease diameter of small intestine) –> longitudinal muscle tissue (contracts to shorten small intestine) –> serosa (connective tissue
Mouth
- function, structure, exocrine, endocrine
Function
- grinds & moistens food
- mostly starch digestion, little bit lipid digestion
Structure
- Teeth
- Tongue
- Salivary glands (which produces saliva)
Exocrine
- saliva: mucus & water
- lingual lipase: digests lipids
- amylase: digests starch
- lysozyme: antibacterial (breaks down bacteria cell wall)
Endocrine
NONE
Esophogus
- function, structure, exocrine, endocrine
Function
- tube from mouth to stomach
Structure
- Starts with skeletal then smooth muscle (skeletal because initiates swallowing which is voluntary)
- Cardiac sphincter (prevents acid reflux between esophogus and stomach)
Exocrine
NONE
Endocrine
NONE
Stomach
- function, structure, exocrine, endocrine
Function
- store food, acid hydrolysis, grinding
Structure
- Gastric Gland - spread out on walls of stomach (chief cells, parietal cells, mucus cells
- Pyloric Sphincter - between the stomach & SI; regulates entry of food into small intestine
Exocrine
- Chief cells release pepsinogen which as it climbs up gastric gland it comes into contact with HCl released by parietal cells
- this activates pepsinogen to pepsin
- to prevent work of pepsin on wall, mucus cells produce mucus because otherwise pepsin will digest stomach wall and cause bleeding and pain
Endocrine
G cells produce the hormone called gastrin
- increases release of food from stomach to small intestine
- stimulates gastric gland
- trigger to shut it off is too much food in SI and if pH is acidic because don’t want to release more acid into stomach
Small intestine
- function, structure, exocrine, endocrine
Function
- digestion & absorption
Structure
- Duodenum (5%), Jejunum (40%, Ileum (55%)
- Increase in SA (plicae which have villi, each villus has microvilli which have brush boarders)
Exocrine
- Trypsinogen –> Trypsin in presence of enterokinase
- brush boarder enzyme: disaccharidases & dipeptidases
Endocrine
- Enterogastrone: decreases release of food from stomach to small intestine (trigger is full small intestine)
- secretin: increases bicarb release (trigger is if pH is acidic)
- CCK: increases bile release (trigger is fat)
Large intestine
- function, structure, exocrine, endocrine
Function
- stores feces & water absorption
Structure
- bacteria & vit k relationship
- Ileocecal valve: valve between ileum & cecum which is normally closed but opens and relaxes in presence of food in stomach
- internal & external anal sphincters
Exocrine
NONE
Endocrine
NONE
