Organ
Organ system
a structure that is made up of more than 1 tissue that perfoms a specialized function
A group of organs that woek together to perform a specific task
Respiratory system
- Lungs
- trachea
- air passageways
supplies blood with O2 and removes CO2
Urinary system
- Kidneys and associated structures
eliminates wastes and regulates the balance of water, electrolytes, and acid in the blood.
* Eliminates metabolic waste products*
Endocrine system
- pituitary gland
- adrenal gland
- thyroid gland
secretes that regulate process such as growth, reprodution, and nutrient use
*HORMONES*
Digestive system organs
- mouth
- pharynx
- salivary glands
- esophagus
- liver
- stomach
- pancreas
- gallbaldder
- small intestine
- large intestine
-
anus
*
Digestion
Breaking down of food into nutrients so they can be absorbed
Absorption
goes from inside the lumen to the body
Mucus
secreated from mucosal cells lining the digestive tract
- moistens
- lubricates
- protects
Enzymes
speed up reactions
for digestion, they help break down larger molecules into smaller ones
hormones
chemicals secreted from cells which travel through bloodstream to signal cells in another part of the body
bolus
ball of food with saliva
Epiglottis
blocks food from entering TRACHEA (windpipe) and lungs during swallowing
Sphincters
Lower esophageal sphincter
pyloric sphincter
Stomach
serves as TEMPORARY STORAGE of food
the stomach lining produces gastric juices
the churning of stomahc muscles mixes food
- very little absorption
- water, alcohol, aspirin, tylenol
ends in chyme
leaves through pyloric sphincter to small intestine
Gastric juice
Contains:
- water
- pepsiongen (precurser to pepsin-digestive enzyme for protein)
- Mucus
- Hydrochloric Acid (Hcl)
Hydrochloric acid in stomach
- kills microorganisms
- unfolds protein (denaturing)
- activates pepsin
- inhibits amylase (dig. enzyme for carbs)
small intestine
approx 20 ft long
MAIN SITE OF DIGESTION, ABSORPTION
divided in 3:
- duodenum
- Jejunum
- Ileum
inside of it is called lumen.
has large circular folds
segmentation
rhytmic constrictions that move food. like peristalsis
Accessory organs to digestion
- Liver
- gallbladder
- pancreas
*
Pancreas (juice it secretes)
secretes pancreatic juice containing
- bicarbonate- neutralized stomach acid
- pancreatic amylase- digestion of carbs
- pancreatic proteases- protein breakdown
- pancreatic lipases- fats
PA,PP,PL and bicarbonate
Brush border
secretes digestive enzymes for
- Carbohydrates
- proteins
are on microvilli?
Liver function
- produces and secretes BILE
- emulsifies fat so lipases can access molecules
gallbladder function
stores bile and releases it?
Types of transport across membranes
- Difusion
- simple
- facilitated
- Osmosis
- active transport
Diffusion (simple and facilitated)
movmement of substances from HI–>LO areas of concentration
- Simple
- diffusion across membranes
- Facilitated
- diffusion though a membrane protein
Osmosis
diffusion of WATER across membranes
Active transport
movement of substances aceoss membranes against concentration gradients through membrane protein
*requires energy*
Large Intestine
~5 ft long
- cecum
- ascending colon
- transverse colon
- descending colon
- sigmoid colon
- rectum
- anus
absorption of water, some vitamins and mineals
forms feces/shit
has intestinal micoflora (gut microbiome)
Intestinal microflora
- beneficial bacteria
- breaks down fiber
- synthesizes some vitamins
Probiotics
- cibtaubs beneficial bacteria
prebiotics
- food supply for said beneficial bacteria
Gastrointestinal tract
- mouth saliva lubricates, amylase starts carb dig, chewing
- pharynx epiglottis keeps shit in right path
- esophagus peristalsis begins
- stomach food storage, acid killz, unflods proteins, activates pepsin produces chyme
- small intestines most dig. and abs. pancreatic enzymes digest and bicarbonate neutralizes acid. bile emulsifies fat
- large intestines absorb water, bacteria digest fiber, make vitamins
- rectum stores feces
Water soluble nutrients are absorbed into
capillaries then circulatory system
Cap–> Circ
Lipid soluble nutrients are absorbed into
Lacteals then lymphatic system
empties into circulatory system
Lipds–>Lacteals–>Lymphatic system
metabolism
breakdown/syntehsis of molecules
cells use nutrients for energy or to build structures and regulatory molecules
white blood cells (types)
in digestive tissue, they recognize and destory foreign antigens
- Phagocytes
- eat organisms
- lymphocytes
- destory infected cells or secrete anitbodies that bind to antigens leading to their destruction
Food allegies
immune system reacts to nonharmful antigens called ALLERGENS
- 1st exposure
- production of ANTIBODIES
- __2nd exposure
- release of HISTAMINE
- symptoms ensure
- redness, swelling, hives, tingling on tongue/lips, difficulty breathing, decreased bp, vomitting, cramps
anaphylactic shock is a hella allergic shock that needs epinephrine (epi-pen)
common allergies: peanuts, milk, soy, wheat
Celiac disease
Autoimmune condition due to allergic reaction to protein in wheat, rye and barley that form:
gluten
makes the lumen of small intestine to flatten
- reduces surface area
- malabsoprtion results
symptoms:
- bloating
- abdominal cramps
- weight loss
- anemia (iron deficiency in this case)
NO cure
only treatment: avoid foods with gluten
(Rye, wheat, barley, some oats)
can eat:
potatoes, beans, vegetable, fruit, meat
Heartburn VS GERD
heartburn is occasional reflux
GERD is chrnoic
can lead to:
- esophageal bleeding
- ulcers
- cancer of esophagus
Management:
- smaller meals
- beerages between meals
- avoiding fatty foods, chocolate, peppermint
- upright after eating
- avoid smoking/ alcohol
Peptic ulcers
penetration of mucus lining which allows pepsin to damage to damage GI lining
helicobacter pylori (h.pylori)
Gallstones
solid material accumulates in the gallbladder and/or ducts that drain bile to small intestine
symptom: pain
may need cholecystectomy
gall bladder removal
need to avoid fatty shit
Diarrhea
frequent watery stool
caused by:
- bacterial or vial infections
- medications
- chronic diseases
- passage of undigested food into large intestine
Constipation
dry hard stoold
caused by
- too little fiber in diet
- too little water in diet
- lack of exercise
- cerain meds
can lead to diverticula
pouches protruding out from colon wall
pressure on colon wall, can become infected and perforate and spill into body