Abdomen Flashcards
Abdomen part 1
1) The fifth lumbar vertebraes spinous process may be fused with saccrum which may press fifth lumbar nerve.
2) Spina bifida - The two halves of the neural arch may fail to fuse
leaving a gap in the midline. This is called spina bifida. Meninges and spinal cord may herniate outthrough the gap. Meningocele - protrusion of meninges alone with cystic swelling.
Meningomyelocele - When spinal cord is also present in the swelling.
Syringomyelocele - central canal of the protruded part may dilate.
3) Spondylolisthesis - Slipping of greater part of fifth lumbar vertebrae over sacrum leads to this condition and there is also backache and radiating pain along the course of sciatic nerve.
4) Cauda equina syndrome in which there is protrusion of central canal leading to compression of cauda equina along with its roots.
5) Subpubic angle is 80-85⁰ in females and 50-60⁰ in males.
6) Herniation of nucleus pulposus of the intervertebral disc is common in lumbar region. It
presses upon the nerve roots causing severe pain
in the area of cutaneous supply.
7) Structure on ala of sacrum from lateral to medial. OILS
Obturator nerve , Iliolumbar artery , Lumbosacral trunk , Sympathetic chain.
8) Anteroposterior , oblique and transverse diameters are same in pelvic cavity.
Abdomen part 2
Remnants of the vitellointestinal duct may form a tumour at the umbilicus called as raspberry tumor.
#persistence of patent vitellointestinal duct results in faecal fistula at umbilicus.
#persistance of proximal part of vitellointestinal duct results in meckels diverticulum.
# persistence of middle part of vitellointestinal duct is enterocoele.
#Persistence of the urachus may form a urinary
fistula opening at the umbilicus.
#Umbilical vessels are two tortuous umbilical
arteries and a single umbilical vein.
# Membranous layer of superficial fascia of abdomen is continuous with superficial perineal pouch. Rupture of urethra results urine extravasating this space.
#Hernia is a protrusion of any of the abdominal contents through any of its walls.This is called external hernia. At times, the intestine or omentum
protrudes into the ‘no entry’ zone within the
abdominal cavity itself. The condition is called
internal hernia.
Complications - irreducibility, obstruction and strangulations.
#contents of spermatic cord has 3-3-3 trick -
3 arteries: Testicular artery, artery to ductus deferens,
cremasteric artery.
3 nerves: Genital branch of the genitofemoral,
ilioinguinal, autonomic nerves.
3 other things: Ductus deferens, pampiniform plexus,
remains of processus vaginalis.
the lymphatic and venous drainage.
#At umbilicus, three systems meet. These are
digestive (vitellointestinal duct), the excretory
(urachus) and vascular (umbilical vessels).
# Thoracic 10 spinal nerve supplies the region of
umbilicus
# External oblique is the largest and most superficial
muscle of anterior abdominal wall.
#Internal oblique muscle forms anterior wall, roof
and posterior wall of the inguinal canal and conjoint tendon.
# Rectus abdominis is largest content of rectus sheath.
#Inguinal ligament forms the boundary between
abdomen and lower limb.
# Inguinal hernia lies above and medial to pubic
tubercle. Femoral hernia lies below and lateral to
pubic tubercle.
# Femoral hernia is never congenital
#Femoral hernia is common in females because of
the larger pelvis, bigger femoral canal and smaller femoral artery.
#Paramedian incision in the anterior abdominal
wall is mostly preferred.
#Hernia resulting due to non-return of the umbilical
loop of midgut is congenital
#External oblique aponeurosis forms inguinal ligament
# Transpyloric plane is an imaginary plane passing through the tip of 9th costal cartilage and lower boundry first lumbar vertebrae. It passes
through pylorus of stomach, hila of the kidneys,
fundus of gallbladder, neck of pancreas, origin of
coeliac axis and superior mesenteric arteries.
Abdomen part 3
Phimosis is a condition in which foreskin cannot be retracted from around the tip of the penis.
#Circumcision is the surgical removal of the foreskin.
# Due to laxity of skin and its dependent position,the scrotum is a common site for oedema.
# scrotum is supplied by widely separated
dermatomes so spinal anaesthesia of whole scrotum is difficult to achieve
#Hydrocoele is a condition in which fluid accumulates in the processus vaginalis of peritoneum.
#Unilateral absence of testis—monorchism or
bilateral absence of testis—anorchism.
#Undescended testis or cryptorchidism - The testis may
lie in the lumbar, iliac, inguinal, or upper scrotal
region.
#Ectopic testis: The testis may occupy an abnormal
position due to deviation from the normal route
of descent
# The common causes of epididymitis and epididymoorchitis are tuberculosis, filariasis, the gonococcal
and other pyogenic infections.
# The cavernous tissue is finer in corpus spongiosum
as it contains urethra.
# Penis is supplied by deep, dorsal arteries, artery
to the bulb and superficial external pudendal artery.
# Tunica vaginalis is the lower persistent part of
processus vaginalis, an extension of peritoneal
cavity.
# Right testicular vein drains into inferior vena cava.
Left testicular vein drains into left renal vein.
# Lymph node of Cloquet is involved in cancer of
the penis.
# Hydrocoele is the commonest cause of swelling of
the scrotum.
#Testis begins to descend during 2nd month of
intrauterine life reaches iliac fossa (3rd month) reaches inguinal canal in 7th month, comes down to
superficial inguinal ring during 8th month and
reaches scrotum during 9th month.
#Testis is supplied by sympathetic trunk from T10 segment.
#Lymphatics from glans penis drain into deep inguinal lymph nodes.
# Needle pierce structures in testis to drain hydrocoele like tunica vaginalis , internal spermatic fascia , cremasteric muscle and fascia.
#Artery of ductus deferens is part of internal iliac artery
# Fascia transversalis of abdominal wall forms internal spermatic fascia as covering of testis.
Abdomen part 4
• There are 9 regions of the abdominal cavity.
•Abdominal part of foregut has a dorsal and ventral
mesentery each.
•Midgut and hindgut have only the dorsal
mesenteries each.
•Lesser sac with its fluid prevents compression of
most of the posterior abdominal organs by the full
stomach.
•Rectouterine pouch in female is 5.5 cm from surface
of perineal skin
• Rectovesical pouch in male is 7.5 cm away from
the perineal skin.
• Peritoneal recesses are mostly present at the junction
of intraperitoneal and retroperitoneal organs.Right posterior subphrenic space or Morrison’s
pouch is the deepest pouch in lying position.
• Spleen forming stomach bed is separated from
stomach by the cavity of greater sac. Other organs
forming bed are separated from stomach by lesser
sac.
#Pancreas, duodenum and kidney are retroperitoneal organs.
#Ligamentum teres is remnant of left umbilical vein.
#Inferior mesenteric vein is related to para duodenal fossa.
# Posterior relation of foramen of Winslow is IVC
#Lining of peritoneum is called mesothelium
#Visceral peritoneum is derived from splanchnic mesoderm.
#Peritoneum is very loosely attached to anterior abdominal wall close to urinary bladder.
#Rectum does not have mesentery
# All parts of duodenum are retroperitoneal, except first 2.5 cm of 1st.
#Ganglia situated in the submucosal and myenteric
plexuses of intestine is parasympathetic.
Inferior vena cava
Inferior Vena Cama is formed at the level of 5th lumber vertebra on right side by union of right and left common iliac veins.
Tributaries
1) Right & Left common iliac veins.
2) Third and fourth lumbar veins
3) Right testicular or ovarian vein
4) Renal veins
5) Right suprarenal vein
5) Hepatic veins
Development
Inferior vena cava develops from
1) Anastomoses of right and left posterior cardinal veins
2) Right supracardinal vein
3) Right suprasubcardinal vein
4) Right subcardinal vein
5) Right hepatocardiac channel
Quadratus lumborum
It is a quadrate muscle lying in lumbar region.
Origin - Transverse process of L5 & iliolumbar ligament
Insertion - Transverse process of upper 4 Lumbar vertebrae & lower border of 12th rib.
Nerve supply - Ventral Rami of spinal nerves T12 to L4.
Actions -
1) Fixes last rib so contraction of diaphragm can take place more effectively.
2) Can cause lateral flexion of vertebral canal.
3) Muscles of both sides together can extend lumbar vertebral column.
Suprarenal gland
Blood Supply -
• Arterial
1) Superior suprarenal artery branch of inferior phrenic artery.
2) Middle suprarenal artery branch of abdominal aorta.
3) Inferior suprarenal artery branch of renal artery
•Venous
1) Right suprarenal vein draining into inferior vena cava.
2) Left suprarenal vein draining into left renal vein.
++DEVELOPMENT++
•Cortex develops from mesoderm(coelomic epithelium) and medulla develops from ectoderm(neural crest cells).
• Congenital adrenal hyperplasia in which there is increase in number of cells of adrenal cortex causing increased androgens secretion during feotal period causing masculization of females.
++APPLIED ANATOMY++
1) Addisons disease caused by atrophy of suprarenal cortex results in muscular weakness and low blood pressure.
2) Pheochromocytoma is tumor of adrenal medulla producing large amount of catecholamines causing high BP and headache.
Diaphragm
Origin-
1) Sternal part arises from posterior surface of xiphoid process.
2) Costal part arises from lower six ribs and costal cartilages.
3) Lumbar part arises from
Medial and lateral lumbocostal arch
Right and left crus and median arucate ligament.
Insertion - Trilobar central tendon.
Nerve supply -
Motor nerve is phrenic nerve from C345
Sensory nerve is phrenic nerve for central part and lower six thoracic nerves for intercostal parts.
Actions-
1) Principle muscle of inspiration
2) Acts in expulsive acts
3) Sphincteric action in lower part of oesophagus.
Clinical anatomy.
1) Hiccups results due to splasmodic contraction of diaphragm. Which can be due to irritation of diaphragm or nerve supplying it or due to irritation of hiccup centre in medulla.
2) Irritation of diaphragm cause referred pain to shoulder tip because supraclavicular and phrenic nerve have same origin of C345.
3) Unilateral paralysis of diaphragm due to lesion to phrenic nerve causes paradoxical movements.
4) Diaphragmatic hernia
• Congenital - posterior , posterolateral , retrosternal and central hernia.
• Acquired hernia which may be traumatic and hiatal.
Openings-
1) Aortic opening at T12 vertebra transmitting aorta, thoracic duct and azygos vein.
2) Oesophageal opening transmitting oesophagus, gastric or vagus nerve and Oesophageal branches of left gastric artery and Oesophageal veins.
3) Vena caval opening at central tendon at level of T8 vertebrae transmitting inferior vena cava, branches of right phrenic nerves and lymphatics of liver.
