Prelims - INTESTINAL FLUID AND ELECTROLYTE MOVEMENT (Dr. Salumbides) Flashcards
These regulate both epithelial transport and motor activity during both the interdigestive and postprandial periods.
Enteric Neurons, as well as Endocrine and Paracrine Agonists
ABSORPTION of dietary nutrients is an exclusive function of
Small Intestine
What absorbs fluid and electrolytes
Both Small Intestine and Large Intestine
The SI has a _________, whereas
the Colon has __________ with __________.
Villous-crypt Organization
Surface Epithelial Cells
Interspersed Crypts
The SI cosist of finger-like projections ________ surrounded by openings of glandular structures called __________
Villi
Crypts of Lieberkühn, or simply Crypts
The cells lining the VILLI are considered to be the primary cells responsible for
Both nutrient and electrolyte absorption
CRYPT CELLS primarily participate in
Secretion
TRUE or FALSE
The colon has a villi
FALSE
- Colon does not have a villi, instead the cells lining the large intestine are SURFACE EPITHELIAL CELLS, and interspersed over the colonic surface are numerous APERTURES OF COLONIC CRYPTS (OR GLANDS)
The SURFACE EPITHELIAL CELLS of the colon are the primary cells responsible for
Colonic electrolyte absorption
The COLONIC GLAND CELLS are generally believed to
Mediate ion secretion
The ZONE OF CELL PROLIFERATION is at the
Base of the Crypt
TRUE or FALSE
The intestinal mucosa is a dynamic organ with continuous cell proliferation and migration
TRUE
This is a stem cell that differentiates into several specialized cells (e.g., vacuolated, goblet and Paneth cells)
Progenitor cells
The __________ migrates along the crypt-villus axis and becomes a villous absorptive cell after undergoing substantial changes in its morphological and functional characteristics.
Vacuolated cell
The overall period from initiation of cell proliferation to sloughing is
48-96 hrs
DECREASED cell turnover occurs during
Fasting
INCREASED cell turnover occurs during
Feeding and Lactation
Length (m) of SI and Colon
6
2.4
Area of apical plasma membrane (m2) for SI and Colon
~ 200
~ 25
YES or NO
Villi in COLON
Nutrient Absorption in COLON
Microvilli in COLON
Active Na Absorption in COLON
Active K Secretion in SI
Active K Secretion in COLON
Active Na Absorption in SI
Microvilli in SI
NO NO YES YES NO YES YES YES
The SI is amplified at three levels
(1) Folds of Kerckring
(2) Villi and Crypts
(3) Microvilli
The Colon is amplified at three levels
(1) Semilunar folds
(2) Crypts (but NOT VILLI)
(3) Microvilli
Thus, if the SI is thought of as a hollow cylinder, the net increase in total surface area of the small intestine (versus that of the smooth cylinder) is
600-fold
The fluid content of average diet is typically
1.5 - 2.5 L/day