ABDOMEN - Team Motivation › onlinetest › backend › source › Anat4... · 2018-09-06 ·...

ABDOMEN

Boundries of abdomen

• Roof

• Floor

• Anterior wall

• Posterior wall

Content: • Rectus abdominis & pyramidalis • Superior & inferior epigastric vessels • Lower 5 intercostal & subcostal nerves

Rectus sheath

INGUINAL CANAL

• Musculo-apponeurotic tunnel

• About 4 cm in length

• Extends from deep inguinal ring

to superficial inguinal ring

Inlet (Deep Inguinal Ring)

Outlet (Superficial Inguinal Ring)

Anterior wall

Posterior wall

Floor – Poupart’s ligament

Roof

INGUINAL HERNIA

An abdominal content covered by peritoneum enter the

inguinal canal

Content of hernial sac vary from a piece of omentum to small

or large intestine

When Meckel’s diverticulum enter - Littre’ s hernia

Two types:

• Indirect /oblique

• Direct

Defensive mechanism of inguinal canal (or Shutter mechanism)

Falp valve mechanism – In increased IAP the posterior wallof canal is

pushed forward & come in contact with anterior wall obliterating the

canal

Ball valve mechanism – In increased IAP the cremaster muscle in

male contract & pull the testes towards the superficial ring thus the

outlet of the canal is closed like a plug (cremasteric plug)

At the 4th month of foetal life testis appears in iliac fossa

at 7th month it reaches deep inguinal ring

During 8th month it travels the inguinal canal

finally reaches srotum at or slightly after birth

Descent of Testis

Abdominal aorta

Celiac Artery

Superior mesenteric Artery

Inferior mesenteric Artery

Abdominal aorta

Inferior vena cava

HEPATIC PORTAL VEIN

Valveless Drain • Abdominal part of GIT (from lower third of oesophagus to halfway down the analcanal) • Spleen • Pancreas • Gallbladder

Length : 5 cm

sometimes the trunk of vein presents a dilatation, portal sinus, just before its division

Porta-caval anastomosis

At lower end of oesophagus

At the umblicus spokes of

wheel (Caput Medusae)

At lower end of rectum and

anal canal

THE PERITONEUM

Largest serous sac in to which organs are pressed from outside

Consist of

• Parietal peritoneum

• Visceral peritoneum

Peritoneal cavity

• Male - closed sac

• Female - open sac

• Present two inter communicating sac – (Epiploic foramen / foramen of winslow- T12, 3 cm)

Greater sac

Lesser sac (omental bursa)

Primary retroperitoneal organ: Suprarenal gland

Urinary : kidney

ureter

bladder

Circulatory : aorta

Inferior Vena Cava (IVC)

Digestive : rectum (part, lower 1/3rd extraperitoneal)

Secondry retroperitoneal organ: Head,neck & body of pancreas (tail-peritoneal)

Duodenum (except proximal first segment- peritoneal)

Ascending & descending colon

Peritoneal folds

Omenta : connect stomach with other abdominal organs

• Lesser omentum : stomach liver

• Greater omentum : stomach transverse colon

(abdominal police gaurd)

Mesentry : connect gut from posterior abdominal wall

• The mesentry – connected with jejunum & ileum

• Transverse mesocolon – with transverse colon

• Sigmoid mesocolon – with sigmoid colon

Gastrointestinal Tract (GIT)

STOMACH

Most dialated part of GIT

Capacity:

• 30-50 ml- newborn

• 1000 ml- puberty

• 1500 ml- adult

Shape : J shape (in living)

sickle shaped (in cadaver)

Clinaclly 3 types

• Sthenic normal type

• Hypersthenic steer horn stomach

• Hyposthenic (Asthenic)

Gastric triangle

• Area of stomach in contact with anterior abdominal wall • Boundries: Right side - lower border of liver Left side - left costal margin Below - transverse colon • In complete esophageal obstruction, a tube is introduced in stomach through gastric triangle for feeding the patient

Stomach Bed

• Left crus of diaphragm

• Left suprarenal gland

• Anterior surface of left kidney

• Splenic artery

• Anterior surface of pancreas

• Anterior layer of transverse mesocolon &

sometimes left colic flexure

• Spleen – when stomach is distended

GIT histology

• Submucosal plexus (of Meissner)- in

submucosa

• Myentric plexus (of Auerbach)-

between CML & LML

Gastric glands

Cardiac gland – mucus secreting cells

Pyloric gland – mucus secreting cells &

neuroendocrine cells

Principle gland – most highly specialized

• in body & fundus

• Cell types :

Chief (peptic) cells - pepsin & lipase

Parietal (oxyntic) cells – gastric acid, intrinsic factor

(necessory for absorption of vit. B12)

Mucous neck cells

Stem cells

Neuroendocrine (enteroendocrine)cells

G cell -> gastrin

D cell -> somatostatin

Enterochromaffin like cell -> histamin

Isthmus : dividing and undifferentiated

cells

Neck : mucous neck cells, parietal cells, &

enteroendocrine cells including APUD cells

Fundus/basal : mainly chief cells, some

parietal cells, and several types of

enteroendocrine cells.

Blood Supply

INTESTINE

Small intestine : ( 6.5 m = 21’)

• Duodenum – 25 cm (5,8 10, 2.5)

(Do-deca dactulos)

• Jejunum – 2.5 m

• Ileum- 3.7 m

Large intestine : (1.5 m = 6’)

• Caecum - 6-7 cm

• Colon - 1.3 m (15, 50, 25, 40 cm)

• Rectum – 12 cm

• Anal canal – 3.8 cm

Taeniae coli

Sacculation / Haustration

Appendices Epiploicae

Small Intestine

Diagramatic sketch of Villous structure

Epithelium

Arteriole Venule Lymphatic (lacteal)

Capillary network

45

Small intestine 1: Duodenum V- vill, G-glands in submucosa

Small intestine Large intestine

(Valve of Kerking)

Vermiform Appendix

Narrow worm like tubular diverticulation from postero- medial wall of caecum 2 cm below ileocaecal junction

Length : 2-20 cm (9 cm) Parts :

• Base • Body • Tip : variable in position:

retro-caecal (12 o’clock) : 60 % pelvic (4 o’clock) : 30 % pre-ilial (2 o’clock) : most dangerous (b/c

inflammation from appendix spreads to general peritoneal cavity)

Mc Burney’s point : maximum tenderness in appendicitis Arterial supply : appendicular artery, a branch of iliocolic artery

Psoas sign

The Mesentry

Free border- 20 feet long

Vertebral border (root) -15 cm long

• Extends from left side of L2 vertebra at

duodeno-jejunal flexure to right sacro-iliac

joint at ilio-caecal junction

• Structures crossed by the root (from above

downwards)

3rd part of duodenum

Abdominal aorta

IVC

Right gonadal vessels

Right ureter

Right psoas

Right genito-femoral nerve

Right sacro-iliac joint

Anal canal

Anal columns (column of Morgagni): 6-10

Anal valve (valve of Ball)- crescentric mucous folds

connecting lower ends of anal columns

Anal papillae : epithilial processes from free margin of

anal valves, remnant of anal membrane

Anal sinus

LIVER Largest gland of body

Colour : reddish brown

Shape : wedge shape, broad base

towards right

Absolute weight :

• At birth : 150 gms

• Adult male : 1.4-1.8 kg

• Adult female : 1.2- 1.4 kg

Proportional Weight :

• In new born : 1/18th of body weight

• In adult : 1/36th of body weight

Situation : whole right hypochondrium,

upper part of epigastrium

• Occupies 2/5th of abdomen Riedel’s lobe

Lobes of the Liver • Right lobe - 5/6th • Left lobe - 1/6th

Surfaces of liver • Parietal surface –

Anterior Posterior Superior Right lateral – biopsy through

9th/10th ISC during forced expiration • Visceral / inferior o Porta Hepatis – not a true gateway Structure at porta hepatis – before backward : (DAV) R&L hepatic duct R&L branch of hepatic artery R&L branch of portal vein

Segmental Anatomy of Liver– Couinaud Segments

LIGAMENTS OF LIVER

Peritoneal folds/ False ligament

True ligaments

• Ligementum teres hepatis

– Remnant of obliterated left umbilical vein

– Extends from umbilicus to left branch of portal vein at porta hepatis

– Pass along free border of Falciform ligament & floor of the fissure for ligamentum teres

– In foetal life- Left umblical vein conveys oxygenated blood from placenta to fetus

• Ligamentum venosum

– Remnant of obliterated ducts venoces which is foetal ife connect left branch of portal vein with IVC (or upper hepatic vein)

– In foetal life- most of blood of left umbilical vein shunts to IVC via ductus venosus after bypassing hepatic circulation

Blood Supply to Liver

• Hepatic artery (20%)

• Portal vein (80%)

Hepatic vein

Structural Organization of the Liver

Parenchyma

Connective tissue stroma

continuous with fibrous capsule

of Glisson

Sinusoidal capillaries (sinusoids)

Perisinusoidal spaces (spaces of

Disse)

Micro-structure of Liver

Classical lobule

Portal lobule

Hepatic acinus

Space of Disse (perisinusoidal space) Space of Moll (periportal space) Kupffer cell : belong to mononuclear phagocytotic system

Hepatic stelate cell (ito cells) : • Filled with cytoplasmic vacuoles containing vit. A • In certain pathologic conditions, these cells lose their storage vacuoles and differentiate

into myofibroblasts that produce collagen fibers, leading to liver fibrosis

1. Periportal zone 2. Transitional zone 3. Pericentral / centrilobularzone

Gall Bladder

Shape : pear shaped

Colour : grey blue

Capacity : 30-50 ml

Length : 7-10 cm

Partts :

•Fundus- just below the tip

of 9th costal cartilage

•Body

•Neck cystic duct

Hartmann’s pouch- small

diverticulum from neck

Callot’s triangle :

content -cystic artery

Nerve supply

Parasympathetic

Motor to musculature of gall bladder & bile duct

Inhibitory to sphincter

Sympathetic (T7-T9)

Vasomotor

Motor to sphincter

A/A

• Inflammation of gall bladder- k/a cholecystitis is more frequent in (5 F) fair, fertile,

fatty, female & above forty years of age

PANCREAS

Mix gland

Exocrine part : enzymes

Endocrine part (islet of Langerhans):

hormones

• Alpha cells (20%) : glucagon

• Beta cells (68%) : insulin

• Delta cells (10%) : somatostatin

• PP cells (2%) : pancriatic polypeptide

hormone -> inhibit intestinal mobility

Parts : head, neck, body, tail

Duct :

• Main duct ( duct of Wirsung)

• Accessory duct (duct of Santorini)

Length 12-15cm

Breadth 3-4cm

Thickness 1.5-2cm

Weight 80-90gms

Annular pancrease : vetral pancreas splits & form a ring around the duodenum, occasionally resulting in duodenal stenosis

SPLEEN Largest lymphatic organ

Graveyard of rbc

In foetal life – manufacture Erythrocytes

After birth – manufacture lymphocyte

Measurements : Harris dictum: 1, 3, 5, 7, 9, 11

Weight - 7 oz (150 gm)

Ligaments of spleen

Gastro-splenic ligament : shotr gastric & left gastro-

epiploic vessels

Lieno-renal ligament : spleenic vessels

Phrenico-colic ligament (sustantaculum lienis)-

support the spleen from below

Lieno-phrenic ligament : Suspensory ligament of

spleen

White pulp (malpighian body) : consisting of lymphatic nodule

arranged around an ecentric arteriole

Red pulp : (75%) consist of

• Venous sinuses

• Splinic cord of Billroth :

KIDNEY Essential organ of excretion

Shape : bean shaped with hilum directed

medially

Situated retroperitoneally in posterior

abdominal wall by sides of vertebral

column

Extends from T12- L3 vertebra

Right kidney- slightly lower than left kidney

Left kidney-longer, narrower & more

nearer to vertebral column than right

Measurement: 11 X 6 X 3 cm

Weight : male 150-170 gms

Female 130-150 gms

Structures passing through hilum- from

before backwards (VAP)

Renal vein

Renal artery

Pelvis of ureter

As a rule, one branch of renal artery &

corresponding tributary of renal vein pass

behind the pelvis

In addition the hilum transmits renal

lymphatics, nerves & perinephric fat

Coverings of kidney

Fibrous capsule (true capsule)

Perinephric fat (adipose tissue)

Renal fascia (false capsule, fascia

of Gerota)

• Anterior layer- thin & k/a Fascia of Toldt

• Posterioe layer- thick & k/a fassi of Zuckerkendl

Paranephric fat

Renal angle

Outer : renal substance

• Cortex : renal columns

cortical arches- has

medullary ray

convoluted parts

• Medulla: 8-18 pyramids

Inner : renal sinus- has

Renal blood vessels

Perinephric fat

Minor calyces (7-13)

Major calyces (2-3)

Pelvis of ureter (5-7 ml)

Each papilla is perforated by 16-20 or more duct of

Billini & received by minor calyx.

As a rule, one minor calyx receives 1-3 renal papilla

Structure of Kidney

NEPHRON

Structural & functional unit of kidney

Number : about one million in each kidney

Length : 50-55 mm

Each nephron consist of :

• Malpighian (or Renal) capsules : for filteration &

consist of

o Bowman’s capsule - lined by Squamous epithelium

o Glomerulus - a network of blood capillaries

• Neck

• Tubules : for selective reabsorption of filtrate until

urine is formed & consist of

o Proximal convoluted tubule (PCT)

o Loop of Henle’s

Descending limb - thinner

Ascending limb - thicker

o Distal convoluted tubule

• Lobe of kidney- one pyramid capped with

adjoining cortex

• Lobule of kidney - an area of the cortical

arch bounded on each side by inter-

lobular blood vessel & presenting in the

central axis of single medullary ray

Arterial supply of kidney

Ureters

Thick- walled cylindrical tubs

25 cm long

3 mm in diameter

Consist of 3 parts

• Pelvis (5-7 ml)

• Abdominal part

• Pelvic part

Constrictions of uretor : 3, developmental

• At pelvi-uretric region

• At pelvic brim

• At the point where ureter pierces bladder

wall

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