Theme 1 anatomy Flashcards
Endoderm
Mesoderm
Ectoderm
Majority of gut, including most of epithelium and glands of digestive tract
Muscular layers
Epithelium at extremities of tract (cranial and caudal
Primitive gut
- formed by
- membranes
Formed by 2 folds: Cranial-caudal and lateral
Week 4: Cranial and caudal ends closed by bucco-pharyngeal and cloacal membranes
Primitive gut formed by
Cranial-caudal and lateral folds
Gut divisions
Foregut
Midgut
Hindgut
Foregut [5]
Oesophagus Stomach Proximal half Duodenum Liver Pancreas
Midgut [6]
Distal half duodenum, Jejunum, Ileum, Cecum, Asc. + ¾ Transv. Colon
Hindgut [4]
¼ Transv. + Desc. + Sigmoid Colon & rectum
Primitive gut held by
mesenteries
Mesenteries [3]
Formed by double layer of peritoneum
Dorsal or mesentery
Suspend gut organs
Pathway for blood, innervation, lymphatics to reach gut
Ventral mesentery [3]
Degrades except for foregut
- ligament around liver
- falciform ligament
- lesser omentum
Lesser omentum [2]
Attach lesser curvature stomach to back of liver
Free edge
Dorsal mesentery [5]
Attach gut organs to posterior abdominal wall
- gastrosplenic
- lienorenal
- greater omentum
- mesentery of SI and LI
Abdomen [2]
Trunk below diaphragm
Abdominopelvic: abdomen proper + greater pelvis
External abdomen wall [2]
Flat abdominal muscle
Lumbar vertebral column
External oblique [4]
Outer surface of lower 8 ribs to
- linea alba
- iliac crest
- pubic tubercle
Internal oblique [4]
Lat 1/3 inguinal ligament and ant 2/3 of iliac crest
to
Linea alba
Costal margin
Crest of pubic bone
Transversus abdominis [4]
From: lat 1/3 inguinal ligament
int surf lower 6 ribs
iliac crest
To: linea alba
crest of pubic bone
Rectus abdominis [3]
From: pubic symphysis + crest
To: xyphoid process
5th-7th costal cartilages
VAN of anterior abdominal wall
Arteries: Sup and Inf epigastric, intercostal,
circumflex iliac
Veins: thoracoepigastric
(between lat thoracic and Sup epigastric)
Nerves: Thoracoabdominal nerves (also thoracic
and subcostal nerves for rectus abdominis)
Anterior abdominal wall functions [4]
Ext Obl: work with Int Obl for torsional movement of trunk
Int Obl: flex and rotate trunk; compress viscera
Transv Abd: compress and support viscera
Rectus Abd: flexes trunk; compress viscera
Inguinal canal passage for [4]
- spermatic cord to reach the scrotum in the male
- the round ligament of the uterus to reach the labia majora in the female
Limited by the superficial and deep inguinal rings (DR)
For both genders the genital nerve (a branch from the genitofemoral) and other blood and lymphatic vessels also travel through this canal
Spermatic cord consists of [5]
vas deferens, gonadal vessels, nerves, lymphatics and the cremaster muscle
Spermatic cord passes through the abdominal wall and takes sleeve from [3]
transversalis fascia => contributes the innermost covering of the spermatic cord – the internal spermatic fascia
internal oblique => contributes the middle covering layer to the cord – the cremasteric fascia
the external oblique => contributes the outer covering of the cord – the external spermatic fascia
Anatomical subdivisions
- Upper Right & Left
- Upper Middle
- Middle Right & Left
- Lower Right & Left
- Lower Middle
- Hypochrondriac
- Epigastric
- Lumbar
- Inguinal (iliac)
- Hypogastric (pubic)
Right upper contents [6]
Duodenum Gallbladder Asc & Transverse colon Hepatic flexure of colon Pancreas head R liver lobe
Left upper contents [6]
Splenic flexure of colon Transverse and Desc colon Stomach Spleen Pancreas body L liver lobe
Right lower contents [4}
Caecum
Appendix
Small intestine
Asc colon
Left lower contents {3}
Small intestine
Sigmoid and desc colon
Oral cavity [5]
Teeth Palate - nasal cavity Tongue Salivary glands Pharynx
Oesophagus [5]
Pierce diaphragm Open to stomach 25 cm Posterior to trachea Muscular wall
Gaster
Most dilated of alimentary canal
Between oesophagus and SI
Curvature and surfaces - 2 openings
Stomach [8]
Gaster
Most dilated of alimentary canal
Between oesophagus and SI
Curvature and surfaces - 2 openings
Cardial and pyloric
Lesser curvature = superior border
Greater curvature = inferior border
Lognitudinal, circular and oblique muscle layers
Small intestine [4]
Convoluted tube
5m
Pylorus -> ileocaecal junction
3 subdivisions: duodenum, ileum and jejunum
Duodenum [3]
Retroperitoneal
4 parts: horizontal and superior
Duct (pancreas and gallballder) -> duodenal-jejunal flexure
Jejunum/ileum [3]
3m
Duodenal-jejunal flexure -> ileocael junction
One attached and one free edge
Large intestine [4]
1.5m
End ileum to anus
4 parts: Transverse and sigmoid
Asc and desc = retroperitoneal
Sup mesenteric branches [4]
Middle and right colic
Ileocaecal
Jejunal and ileal branches
Distal part duodenum to proximal 2/3 of transverse colon
Inferior mesenteric [4]
Distal 1/3 transverse colon to half way down anal canal
Left colic
Sigmoid
Superior rectal
Lymphatics - mesenteric
Superior mesenteric nodes
Inferior mesenteric nodes
Autonomic innervation
- sympathetic
- parasympathetic
Symp: Splanchnic n and symp trunk and ganglia
Parasym: Vagus n and pelvic splanchnic
Liver functions [4]
detoxification
protein synthesis
production of bile – accessory GI organ
glycogen storage
Liver location
Located below diaphragm: mostly the right hypochondrium & epigastrium, but extends into left hypochondrium
Liver
- ant view
- posterior view
- Peritoneum cover
Ant: Left and right
Post: Quadrate and caudate
Bare area - connects with diaphragm
Falciform (ant) and lesser omentum (post)
Porta hepatis - divides the quadrate and caudate lobes
Peritoneal folds [4]
Falciform lig: links diaphragm to upper surface liver ligamentum teres (aka round ligament) at lower end
Round lig: obliterated left umbilical vein
extends to umbilicus
Coronary lig: LInk diaphragm to liver
Lesser omentum: Link liver to stomach
Falciform lig
links diaphragm to upper surface liver ligamentum teres (aka round ligament) at lower end
Round lig
obliterated left umbilical vein
extends to umbilicus
Coronary lig
Link diaphragm to liver
Lesser omentum [4]
Lesser curvature to porta hepatis
Free margin (ventral mesentery)
Enclose: hep artery, portal vein, bile duct and lymph vessel
Close to stomach and enclose gastric arteries and veins
Blood supply to gut [3]
Foregut - Coeliac artery and branch
Midgut - superior mesenteric artery
Hindgut - inferior mesenteric artery
Blood supply to liver [4]
Coeliac artery (trunk or axis) - Left gastric, splenic and hepatic
T12/L1 level
Also supply duodenum and pancreas
Hepatic artery variations
right hepatic artery replaced to the SMA
left hepatic artery replaced to the left gastric artery trifurcation of the common hepatic artery right hepatic artery left hepatic artery gastroduodenal artery (GDA
Porta hepatis
Entry / exit point for hepatic portal vein hepatic artery proper common hepatic duct nerves and lymphatics Hilum of liver - visceral surface
Liver lobule
Branches of hep artery and vein carry blood into sinusoid
+ bile duct = portal triad (corners)
hexagon shaped and contain hepatocytes
Hepatocytes [4]
Synthesis and release plasma proteins into blood
albumin
clotting factors complement cascade components
Deaminates amino acids – urea into blood
Bilirubin to bile pigment
Bile salts – emulsification of fats
