PBL week 2 wrap up Flashcards
describe the location of the oesophagus
long fibromuscular tube
pharynx to stomach, C6 to C11
cross-sectional anatomy of the oesophagus
adventitia
muscularis externa
submucosa
mucosa
adventitia
outer layer of connective tissue (very distal and intraperitoneal portion of oesophagus has an outer covering of serosa instead)
muscularis externa
external layer of longitudinal muscle and inner layer of circular muscle
in superior third: voluntary striated muscle
middle third: voluntary striated and Smooth muscle
inferior third: smooth muscle
how is food transported through the oesophagus
peristalsis
rhythmic contractions of the muscles which propagate down the oesophagus, coordinated by the myenteric plexus
hardening of the muscles can interfere and cause dysphagia
dysphagia
difficulty swallowing
upper oesophageal sphincter
anatomical, striated muscle sphincter
junction between the pharynx and oesophagus
produced by cricopharyngeus
lower oesophageal sphincter
located at the gastro-oesophageal junction
between the stomach and oesophagus
left of the T11 vertebra and marked by change from oesophageal and gastric mucosa
relaxed in peristalsis
layers of the muscularis externa
from superficial to deep
longitudinal muscle
circular muscle
oblique muscle
which region of abdomen is the stomach located
epigastric
partly in the left hypochondriac and umbilical
4 regions of the stomach
cardia: surrounds opening of oesophagus into stomach
fundus: area above the cardia orifice
body: largest region
pylorus: connects stomach to duodenum, divided into the pyloric antrum and pyloric canal and is the distal end of the stomach
2 sphincters of the stomach
inferior oesophageal sphincter: marks transition between oesophagus and stomach at T11, food passes from oesophagus through cardiac orifice into the body of the stomach
pyloric sphincter: lies between pylorus and the start of the duodenum and controls exit of chyme
histology of the oesophagus
mucosa is comprised of 3 different layers
stratified squamous non-keratinised epithelium
lamina propria
muscularis mucosa
stratified squamous non-keratinised epithelium
mucous production
(for lubrication and neutralisation of acid)
protection
lamina propria
absorption via capillaries and also contains MALT for immunological response
muscularis mucosa
for localised movement using muscle contractions to move food down the oesophagus
submucosa
has a large network of blood vessels to increase surface area for nutrient absorption
contains mucus glands for lubrication of bolus
contains Meissen nerve cells which control the effectors
histology of the stomach
simple columnar epithelium
the mucosa and submucosal layer are folded in on themselves which allows them to unfold when the stomach expands
what do gastric pits of the stomach contain
surface lining cells
regenerative cells
mucous neck cells
parietal cells
chief cells
regenerative cells
replace any of the other cells
mucous neck cells
secret mucous and neutralise acid