3. Anatomy of the Abdomen 2 (HARC) GI Tract, peritoneum, embryology, anal canal Flashcards
the GI TRACT is a HOLLOW TUBE with different regions specialised to facilitate which actions:
- MECHANICAL DIGESTION
- CHEMICAL DIGESTION
- WATER REABSORPTION
- Formation, Storage, Expulsion of FAECES
BELOW the DIAPHRAGM what are the MUSCULAR TUBE elements of GI Tract
- OESOPHAGUS
- STOMACH
- SMALL INTESTINE
- LARGE INTESTINE
BELOW DIAPHRAGM, ACCESSORY ORGANS of GI Tract
- LIVER
- GALLBLADDER
- PANCREAS
the STOMACH (J-shaped) is HIGHLY..
DISTENSIBLE (can EXPAND)
what are the 4 REGIONS of the STOMACH
- CARDIA (surrounds opening of oesophagus)
- FUNDUS (superior)
- BODY
- PYLORUS (last)
name the 2 SPHINCTERS of the STOMACH
- LOWER OESOPHAGEAL SPHINCTER
(physiological - prevents backflow) - PYLORIC SPHINCTER
(Anatomical - muscle contracted to keep closed)
what are the 3 LAYERS of SMOOTH MUSCLE in the STOMACH
LONGITUDINAL
CIRCULAR
OBLIQUE
what do the SMOOTH MUSCLE of the STOMACH allow for
powerful CHURNING
- MECHANICAL DIGESTION
what are the names of the FOLDS in the MUCOSA of the stomach that LINE in
RUGAE
what do the RUGAE of the STOMACH allow for
INCREASE SURFACE
& allow for STOMACH EXPANSION
(flatten when stomach fills)
STOMACH releases CHYME (semi-fluid of partially digested food) into the..
DUODENUM (1st part small intestine)
STOMACH RELEASE of CHYME INTO DUODEUM is controlled / occurs via the..
PYLORIC SPHINCTER
1ST PART of DUODEUM is at which level
L1
SMALL INTESTINE is a MUSCULAR TUBE which 3 PARTS:
- DUODENUM
- JEJUNUM
- ILEUM
what is in the WALL of the SMALL INTESTINE and what is this for
MUSCLE LAYERS
- MIX and MOVE FOOD
(mechanical digestion)
what is in the MUCOSA of the SMALL INTESTINE and what is this for
CIRCULAR FOLDS
- INCREASE SURFACE AREA (have VILLI and MICROVILLI on surface)
& slow chyme down
purpose of CONCENTRIC/CIRCULAR FOLDS in the MUCOSA of the SMALL INTESTINE
INCREASE SURFACE AREA
(VILLI & MICROVILLI)
UNIQUE Feature about the DUODENUM and why is this
IMMOBILE
- as it RECEIVES INPUT from the ACCESSORY ORGANS
in which QUADRANT is JEJUNUM
LEFT UPPER
in which QUADRANT is ILEUM
RIGHT LOWER
subtle vascular and internal DIFFERENCES between JEJUNUM and ILEUM
Jejunum : MORE VASCULAR (‘church wall’ shapes)
LARGER,
WIDER Lumen diameter
THICKER MUSCULAR WALL
MORE CIRCULAR FOLDS
how do the CIRCULAR FOLDS change from JEJUNUM to ILEUM
become gradually LESS PROMINENT
- MORE in JEJUNUM (therefore MORE ABSORPTION)
LARGE INTESTINE / COLON is from the … to the …
from ILIOCAECAL JUNCTION
to
RECTUM
parts of LARGE INTESTINE
- CAECUM & APPENDIX
- ASCENDING COLON
~ HEPATIC FLEXURE
- TRANSVERSE COLON
~ SPLENIC FLEXURE
- DESCENDING COLON
- SIGMOID COLON (S shape)
- RECTUM
name of the LARGE POUCHES on LARGE INTESTINE
HAUSTRA
name of the THIN BAND of MUSCLE found on LARGE INTESTINE
TAENIA COLI
what other UNIQUE FEATURE can be found on LARGE INTESTINES
FATTY TAGS
PRIMARY FUNCTION of the LARGE INTESTINES
WATER REABSORPTION
-> to Create and Excrete FAECES