digestion Flashcards
bolus
mouth rolls food into a bolus to push it towards the phyrnx
phyrnx
- the throat
invvoluntarily pushes bolus towards the esophogus (swallowing)
epiglottis
Small muscle that covers the larynx, prevents food from entering wind pipe
covers the trachea muscle
esophogus
muscular tube that connects the pharynx(throat) to the stomac
moves food bolus to the stomach through involuntary muscle contractions (peristalsis)
secretes mucus for lubrication
peristalsis
moves food bolus to the stomach through involuntary muscle contractions (in the esophogus)
stomach
chemically breaks down materials through acids
- Lower esophageal sphincter prevents bolus from re entering the esophogus (looks like a pinch at the tube entering the stomach)
- stomach contracts to mix the food with gastric secretions (mucus, gastrin, HCI, pesinogen)
- pyloric sphincter controls the flow of chyme (stomach acid) into the duodenum (beginning of the small entestine)
small intestine
absorbs nutrients, vitamins, water, ions
ORDER:
- Duodenum (receives bile from gallblader or liver, and enzymes from pancreas)
- jejunum (digestion finishes, absorption takes place)
- Illium (absoption)
* ***90% of absorption happens in the jejunum and Ileum 10% happens in stomach and large intestine
- intestinal glands secrete enzymes, horomones and mucus to aid digestion
- mesentry attaches and puts the small intestine into place
vili, little folds, help absorption by increasing surface area
large intestine
connects to ileum by ileocecal valve
- absorbs water,vitamis, not a lot of food
- forms feces
SECTIONS:
1. ascending, transverse, descending, colon (ends in rectum and anus)
pancreas
lies below the stomach
releases bicarbonate ions to neutralizy chyme
secretes enzymes
secretes insulin to aid in the absorption of glucose in cells
external respiration
exchange of gases between alveolie and blood
oxygen goes into the blood
carbon dioxide goes out of the lungs
internal respiration
exchange of gases between the blood in capillaries and normal cells
oxyegen diffuses into the cells, carbon dioxide diffuses out of them
larynx
also known as the voice box
produces sounds through vibrations (made of cartilage)
trachea
leads to the lungs
made of cartilage
lined with mucus
cilia sweep mucus and trapped particles out of the trachea
contains the two branches that seperate into lungs (left and right bronchi)
bronciolies
tubes that branch out of the bronchi ,lined with cillia and mucus for filtering
inhalation
diaphrgam contracts and moves down
intercostal muscles contract and expand ribcage
pressure in the ribs decreases, allowing air to flow in
results: volume of ribcage increases, air rushes in
exhalation
diagphram relaxes, moves up
intercostal muscles relax, tightening rib cage
pressure in rib cage increases, making the rib cage smaller and expeling air
resulst: small volume of ribcage, air rushes out
medulla oblogonta
involuntary breathing controlled by the ppart of the brain
chemorecpetors detect co2 levels in the blood
CO2 and water form carbonic acid in the blood, which lowers the pH
Chemoreceptors sense low pH and relay message to stimulate the diaphragm and intercostal muscles
When CO2 levels decrease, and blood pH is returned to normal, the chemoreceptors are inactivated
hemogloobin
oxygen is transported by hemoglobins a protein found in red blood cells
each hemoglobin has four ions, each of which can formn a loose bond with oxygen
when heoglobin is attached to oxygen its called an oxyhemoglobin
transportation of carbon dioxide in cells
Most CO2 in the blood is in the form of carbonic acid (H2CO3) or bicarbonate ions (HCO3)
Some carbon dioxide can be carried by hemoglobin
lung volumes
tidal volume = amount of air that passes in and out of lungs with each breath
total lung capacity = max amount of air that can be held in lungs
experatory reserve volume = air that can be let out after exhaling
inspiratory volue = air that can be let in after inhaling normaly
vital capactiy
max amount of air that can be moved in and out of your lungs (1.5 L less than than total lung capactty
plasma
a fluid in which solid blood components are transported
contains dissolved proteins and nutrients
erythrocytes
red blood cells
produced in the blood marrow
stored in spleen
leukocytes
white blood cells Aid in body defense mechanisms Amoeboid-shaped Destroy bacteria and damaged cells Produced in bone marrow Pus forms at a cut: live and dead WBC, bacteria
plateletes
blood clotting agents
break open, releasing enzymes and other clotting mechanisms
fibrin forms a mesh to clog the wound
Scabs occur when fibrin, platelets and blood clots mesh together
layers of the heart
- smooth inside layer of the heart (endocardium)
- middle layer (myocardium)
- fluid sac called the pericardium
pulmonary circuit
carries deoxygenated blood (enters the right atrium and then the right ventricle)
tricuspid valve prevents it from flowing backwards
then travels to the pulmonary artertyes to the lungs
systemic circuitb
blood filled with oxygen leaves the aortat
