Muscle is a specialized tissue which brings xThe cells exhibit cross-striations under functional unit of muscle fiber. about movement by contraction. xMuscle tissue is made up of cells called myocytes. These usually appear as fibers known as muscle fibers. xEach muscle fiber is covered by a membrane known as sarcolemma and a cytoplasm known as sarcoplasm. xCytoplasm of each muscle fiber contains numerous longitudinal threadlike struc tures called myofibrils, which are made up of different types of muscle protein (mainly actin and myosin). xIt is also rich in mitochondria and glycogen, which provide energy for it. xNumerous mitochondria (sarcosomes) and endoplasmic reticulum (sarcoplasmic reticulum) are also seen. Classification of Muscle Tissue Based on the appearance of contractile cells, the muscle tissue is classified as the following: xSkeletal/striated/voluntary muscle/ striped muscle. xCardiac/involuntary muscle. xSmooth muscle/involuntary/visceral muscle. Skeletal Muscle xSkeletal muscle is attached to bone and is responsible for movement of axial and light microscope; hence, it is called stri ated muscle. xSkeletal muscles have limited capacity of regeneration. Microscopic Structure (Longitudinal Section) of Skeletal Muscle xLongitudinal section of skeletal muscles shows long unbranched cylindrical muscle fibers running parallel to each other (Figs.8.1 and 8.2). xLength of muscle fiber is variable ranging from few millimeter to many centimeter. xEach muscle fiber shows multinucleated flat oval nucleus located peripherally underneath the sarcolemma. xMultinucleated appearance of muscle fiber is due to the fusion of multiple myoblasts during the embryonic life. xThe sarcoplasm contains numerous myofibrils (Fig.8.3). xUnder light microscope, myofibrils are seen as dark and light bands. xThe dark bands are A-bands (anisotropic under polarized light) and light bands are I-bands (isotropic under polarized light). xStriated appearance is mainly due to the regular arrangement of actin and myosin myofilaments. xThe middle of Aband has a light area known as Hband. xThe center of H-band has a dark line known as M-line. xThe center of I-band is bisected by Z-line. xThe area between two Z-lines is called sarcomere, which is the structural and appendicular skeleton.

2. LIVER

3. LIVER
DEFINITION:
• It is the largest gland in the body
SURFACE ANATOMY:
• It occupies the whole right hypochondrium, a part of epigastrium &
a part of left hypochondrium

4. ANTERIOR SURFACE OF LIVER

5. LIVER
SURFACES:
• ANTERIOR: related to diaphragm & anterior abdominal wall.
The diaphragm separates it from pleurae & lungs
• SUPERIOR: related to diaphragm separating it from pericardium
& heart (in the middle) & pleurae & lungs (on each side)

6. POSTERIOR SURFACE OF LIVER

7. LIVER
SURFACES:
• POSTERIOR: formed of (from right to left):
1. Bare area: triangular area related to diaphragm. Its base is
formed by groove for IVC; its sides are formed by upper &
lower layers of coronary ligaments that meet at the apex
to form the right triangular ligament
2. Groove for IVC
3. Caudate lobe: related to diaphragm, projects downwards
to form a process separating IVC from porta hepatis &
forming upper boundary of epiploic foramen
4. Fissure for ligamentum venosum (obliterated ductus
venosus)
5. Esophageal notch

8. INFERIOR SURFACE OF LIVER

9. INFERIOR SURFACE OF LIVER

10. LIVER
SURFACES:
• INFERIOR:
1. Related to the following viscera: right kidney, right suprarenal
gland, right colic flexure, 2nd part of duodenum, fundus & body of
stomach
2. Formed of (from right to left):
• Gall bladder fossa
• Quadrate lobe: related to pylorus, 1st part of duodenum &
transverse colon
• Fissure for ligamentum teres (obliterated left umbilical vein)

11. LIVER
• ACCORDING TO ITS RELATIONS, THE
LIVER IS DIVIDED INTO:
1. DIAPHRAGMATIC SURFACE: includes
superior, anterior & most of
posterior surface
2. VISCERAL SURFACE: includes inferior
& a part of posterior surface

12. LIVER
PORTA HEPATIS:
• It is the hilum of liver
• It lies in the inferior surface of liver
• Structures passing through it: right & left hepatic ducts, right & left
branches of hepatic artery & portal vein (DAV, from before
backwards)+ lymphatics, lymph nodes & autonomic fibers

13. LOBES OF LIVER
ANATOMICAL DIVISION:
• The liver is divided into a smaller left & a larger right lobe by:
1. Falciform ligament: anteriorly
2. Fissure for ligamentum venosum: posteriorly
3. Fisssure for ligametnum teres: inferiorly

14. LOBES OF LIVER
FUNCTIONAL DIVISION:
• The liver is divided into a nearly equal left & right lobes by a plane
passing through groove for IVC & gall bladder fossa.
• The caudate & quadrate lobes are included in the left lobe (because
they are supplied by left branches of hepatic artery & portal vein)

15. LIGAMENTS OF LIVER
PERITONEAL LIGAMENTS
• FALCIFORM LIGAMENT: a triangular fold formed of two
layers (right & left) with:
1. Anterior border: attached to diaphragm
2. Posterior border: attached to anterior & superior
surfaces of liver
3. Lower free border: extending from liver to
umbilicus & enclosing ligamentum teres &
paraumbilical veins

16. LIGAMENTS OF LIVER
PERITONEAL LIGMENTS
• LEFT TRIANGULAR LIGAMENT: to the left of falciform
ligament, the peritoneum is reflected from the
diaphragm to the upper surface of the liver to
form the anterior layer of left triangular ligament
(continuous with left layer of falciform ligament).
The peritoneum then covers anterior, inferior &
posterior surfaces & is reflected to the diaphragm
to form the posterior layer of left triangular
ligament

17. LIGAMENTS OF LIVER
PERITONEAL LIGMENTS
• RIGHT TRIANGULAR LIGAMENT: to the right of falciform
ligament, the peritoneum is reflected from the
diaphragm to the upper surface of the liver to
form the upper layer of coronary ligament
(continuous with right layer of falciform ligament).
The peritoneum then covers anterior & inferior
surfaces then becomes reflected to the front of
right kidney to form the lower layer of coronary
ligament. The right extremity of both layers meet
to form the right triangular ligament

18. LIGAMENTS OF LIVER
PERITONEAL LIGMENTS
• LESSER OMENTUM:
1. It is attached to the margins of porta hepatis & fissure for
ligamentum venosum
2. It extends to lesser curvature of stomach & upper border of 1st
inch of 1st part of duodenum

19. LIGAMENTS OF LIVER
LIGMENTUM M TERES:
•Represents the obliterated left
umbilical vein that originally joins the
branch of portal vein
LIGAMENTUM VENOSUM:
•Represents the obliterated ductus
venosus that originally connects IVC
with left branch of portal vein

20. BARE AREAS OF LIVER
•TRIANGULAR DIAPHRAGMATIC AREA
•GROOVE FOR IVC
•GALL BALDDER FOSSA
•PORTA HEPATIS
•FISSURE FOR LIGAMENTUM VENOSUM

21. BLOOD SUPPLY OF LIVER
• HEPATIC ARTERY: brings oxygenated blood to the liver (30% blood
reaching the liver)
• PORTAL VEIN: brings blood absorbed from GIT to the liver (70% blood
reaching the liver)
• ALL BLOOD PASS TO HEPATIC SINUSOIDS
• Blood leave the liver through HEPATIC VEINS

22. LIVER
LYMPHATIC DRAINAGE:
• Mainly into hepatic lymph nodes in porta hepatis.
Efferent vessels pass to celiac lymph nodes
NERVE SUPPLY: Hepatic plexus of autonomic fibers derived
from celiac plexus
SUPPORT:
1. Hepatic veins (main support): suspend liver from IVC
& have no extrahepatic course
2. Peritoneal folds.
3. Surrounding organs
4. Tone of anterior abdominal wall

23. BILIARY SYSTEM
1. BILIARY DUCTS
2. GALL BLADDER

24. BILIARY SYSTEM

25. COMMON BILE DUCT

26. BILIARY DUCTS
RIGHT & LEFT HEPATIC DUCTS:
• Emerge from porta hepatis
• Drain bile from right & left lobes of liver
• Unite to form common hepatic duct
COMMON HEPATIC DUCT:
• One and half inches in length
• Formed by the union of the 2 hepatic ducts
• Unite with the cystic duct to form the common bile duct

27. BILIARY DUCTS
CYSTIC DUCT:
• One and half inches in length
• Connects the neck of gall bladder to common hepatic duct
• The mucous membrane of the duct as well as that of neck of gall
bladder is raised forming the spiral valve. The valve keeps the
lumen open

28. BILIARY DUCTS
COMMON BILE DUCT:
• Formation: Formed by union of cystic & common hepatic
duct
• Length: Three inches
• Course & relations: It descends:
1. In the free margin of lesser omentum (to the right side of
hepatic artery, anterior to portal vein)
2. Behind 1st part of duodenum (to the right side of
gastroduodenal artery, anterior to portal vein)
3. Behind the head of pancreas, anterior to IVC
• Termination: usually join the main pancreatic duct forming
the ampulla of Vater that opens into the lumen of 2nd part
of duodenum through the major duodenal papilla

29. GALL BLADDER
SHAPE: Pear-shaped sac
SITE: Lies in gall bladder fossa of liver
LENGTH: 3 – 4 inches
CAPACITY: 30 – 50 ml

30. GALL BLADDER
PARTS: Formed of 3 parts:
1. Fundus: projects below inferior margin of liver, lies opposite the
tip of right 9th costal cartilage, related anteriorly to anterior
abdominal wall & posteriorly to transverse colon
• Body: related anteriorly to liver & posteriorly to 1st part of
duodenum
• Neck: continuous with cystic duct has same relation as body

31. GALL BLADDER
PERITONEAL COVERING:
• Fundus: completely covered by peritoneum
• Body & neck: only covered posteriorly
FUNCTION: Stores & concentrates bile

32. SUPPLY OF BILIARY SYSTEM
• ARTERIES: Cystic branch of right hepatic artery
• VEINS: Cystic vein that drains into the right branch of portal vein
• LYMPH DRAINAGE: Cystic lymph nodes, then to hepatic & finally to
celiac lymph nodes
• NERVES: autonomic fibers from celiac lymph nodes