SM int Flashcards
3 parts of sm int
inorder
funcitions
duodenum, jejunum, ileum
Duo- beging of digestion
jejun-major digestion and absorbtion
ileum- absorbs vit b and bile salts
what vessel in the villi absorbs lipds/lymph
the central lacteal
plicae vs microvili and vili
plicae visible w eye- increase 10x sa
vili- increase 10x
microvili- increase 20x, brush border
total 600x
a single villi
-main job
they secrete 2 things
2 types of vessel networks
absorbtion
mucous and hormones
cappilary/blood and lacteal/lymph
majority of absorbtion in
jejeunum
there are no control mechanisms of the absorbtion of
absorption on nutrients
Sodium ions (Na+) and their movement across cell membranes
passive diffusoin
active diffusion
active transport/ co transport
facillitated
-Sodium ions can move down their concentration gradient through passive transport mechanisms. This process does not require energy.
-Active Transport: This process requires energy, usually in the form of ATP, to move sodium ions against their concentration gradient.
- Co-Transport (Secondary Active Transport): Sodium ions are used in combination with other molecules to facilitate their movement. Although the transport of Na+ itself does not require ATP directly, it relies on the gradient maintained by primary active transport.
-Specific channels, like sodium channels, allow Na+ ions to pass through the membrane in response to an electrochemical gradient.
monosachride ex. glucose is aborbtion uses what to be absorbed
Na.
Monosaccharides are absorbed in the small intestine through a process of co-transport with sodium ions (Na+) via the sodium-glucose linked transporter (SGLT1)
3 types of active trasport
Primary Active Transport: Uses energy directly from ATP to move molecules against their concentration gradient, like the sodium-potassium pump.
Secondary Active Transport (Co-Transport): Utilizes the energy from the gradient created by primary active transport to move molecules against their gradient, such as the sodium-glucose transporter.
3° active transport
* Transporter uses concentration gradient of an ion generated
from 2° active transport
* E.g. Na+ /H+ antiporter moves H+ out of the cell, allowing a
H+ /peptide symporter to move small peptides into the cel
dietary protein into AAs by proteolytic enzymes and pepsin
Amino acids and small peptides are absorbed into intestinal epithelial cells via co-transported w sodium ions.
AAs use NA
small peptides use H ion
water is absorbed w what type of transport
active
-a high osmotic pressure is created thorugh NaCl gradient causing water to be drawn through leaky junctoin
how are water soluble viatims absorbed?
passive diffusion with water
how are fat soluble vitamins absorbed?
by micelles
how are bile salts absorbed?
active transport in Ileum
.
How are carbs absorbed?
active transport and facilitated diffusion
How are fats absorbed?
micelles then into chylomicrons
