Divided attention

Posted on Jul 3, 2024 in Biology

Eye- The eyeball is the spherical organ of sight. Its diameter of about 2.5cm. It lies in a bony cavity within the facial skeleton known as the bony orbit. The anterior one- sixth is much more convex than the posterior part.
Anatomically, the eyeball divided into 3 parts;

Fibrous or outer coat.   Vascular or middle coat.   Nervous or inner coat.

1. Fibrous coat: The fibrous layer of the eye is the outermost layer. It is posteriorly formed by the sclera and anteriorly by cornea. Their main functions are to provide shape to the eye and support the deeper structures.

Sclera -It comprises the majority of the fibrous layer (approximately 85%). Sclera is continuous anteriorly with the cornea at the sclerocorneal Junction or limbus. Anteriorly it is covered by conjunc- tiva and the rest of the sclera is covered by Tenon’s capsule that surrounds the eyeball. Sclera is almost avascular.

Cornea- It is transparent, allow light to enter the eyeball and positioned centrally at the front of the eye. It is more convex and separated from iris by the anterior chamber. The cornea is avascular containing neither blood vessels nor lymphatics.

Vascular coat: The vascular layer of the eye lies underneath the fibrous layer. It consists of the choroid, ciliary body and the iris.

Choroid- The choroid is a highly vascular layer consists of a network of blood vessels supported by connective tissues. It provides nourishment to the outer layers of the retina. The choroid represents approxi- mately two-third of the vascular layer and firmly attached to the retina internally and loosely attached to the sclera externally.

Ciliary body-The ciliary body represents an anterior continuation of the choroid and anteromedially it becomes continuous with the iris. The retina ends anteriorly (short distance behind the sclerocorneal junction) in a wavy line called the ora serrata. The ciliary body extends forward and medially from the ora serrata to end near the periphery of the lens. The ciliary body can be divided into a posterior part called ciliary muscles and an anterior part made of the ciliary processes. The ciliary muscle consists of smooth muscle fibres arranged longitudinally, circularly and radially. The contraction of all the muscles, relaxes the suspensory ligament so that the lens become more convex. The ciliary processes lie between the ciliary muscle and the base of the iris. The ciliary processes secrete the aqueous humour and gives attachment to numerous delicate fibres called the zonular fibres, attached to the lens of the eyeball which suspend the lens in its proper position and collectively form the suspensory ligament of the lens.

Iris-The iris is the most anterior part of the vascular coat. It forms a diaphragın placed immediately in front of the lens and its periphery it is continuous with the ciliary body.Iris is colored part of the eye with a central opening called the pupil.The pupil regulates the amount of light passing into the eye. In bright light the pupil contracts and in dim light it dilates.The iris is placed vertically between the cornea and the lens thus divides the anterior segment of the eye into anterior and posterior chamber, both containing aqueous humour.

3. Nervous coat: The inner layer of the eye is formed by retina and it is light detecting component. Retina is composed of two parts-

Outer part: It is attached to the choroid and supports the absorbing of light, preventing scattering of light within the eye ball. It is continuous around the whole inner surface of the eye. Anteriorly the outer part of the retina is continuous and this is known as non visual retina.

Inner part: It consists of photo- receptors, the light detecting cells of retina. It is located posteriorly and laterally in the eye. Posterior part of the retina is called optic part. The optic part of the retina can be viewed during opthalmo scopy. The area that the optic nerve enters the retina is known as the optic disc. It contains no light detecting rods and cons cells called the blind spot. Lateral to the optic disc a small area known as the ‘macula lutea’. It is yellowish in color and highly pigmented. The macula contains a depression called ‘fovea centralis’ which has high concentration of light detecting cells and contains cones only. It is the area responsible for high acuity vision. The retina is composed of ten layers. The layers are named after the primary components in them. Those layers closer to vitreous are called ‘inner’ and those closer to choroid are called ‘outer’.

(i) The outermost layer (close to the choroid) called the retinal pigment epithelium. (ii) Layer of rods and cones (iii) External limiting membrane (iv) Outer nuclear layer (v) Outer plexiform layer (vi) Inner nuclear layer (vii) Inner plexiform layer (viii) Ganglion cell layer (ix) Nerve fiber layer (x) Internal limiting membrane

Chambers of the eye: There are two fluid filled areas in the eye known as anterior and posterior chambers.

Anterior chamber is located between the cornea and the iris. ; Posterior chamber is located between the iris and the suspensory ligament.

Both the chambers are filled with ‘aqueous humour’ clear plasma like fluid that nourishes and protects the eye. The aqueous humour is produced constantly and drains via trabecular meshwork, an area of tissues at the base of the cornea near the anterior chamber.

Lens and vitreous humour- The lens of the eye is located anteriorly, between the vitreous humor and the pupil. Lens is transparent, biconvex structure and its diameter is about 1 cm. Shape of the lens is altered by the ciliary body. The suspensory ligament of the lens retains the lens in position and its tension keeps the anterior surface of lens flattened. Posterior surface of the lens is more convex than the anterior surface. The posterior part of the eyeball, from the lens to the retina is occupied by the vitreous chamber. This segment is filled with a transparent, gelatinous substance- the vitreous humour.

Blood Supply: Eyeball receives the blood supply from the ophthalmic artery, branch of the internal carotid artery.

Veins: Venous drainage of the eyeball is carried out by superior and inferior ophthalmic veins.

Clinical anatomy- Glaucoma, Papilledema, Diabetic retinopathy, Strabismus, Myopia, Hypermetropia, Hyphaema

Middle Ear

The middle ear lies within the temporal bone and extends from the tympanic membrane to the lateral wall of the inner ear. The main function of the middle ear to transmit vibrations from tympanic membrane to the inner ear via ear ossicles. The middle ear divided into 2 parts-

Epitympanic recess                   Tympanic cavity

Epitympanic recess: It is the space superior to tympanic cavity, which lies next to mastoid air cells. The malleus and incus partially extend upwards into the epitympanic recess.

Tympanic cavity: It is located medially to the tympanic membrane and contains three small bones known as ear ossicles which transmit sound vibrations through the middle ear. The tympanic cavity is bounded by as rectangular box, with a roof, floor and anterior, posterior, medial and lateral walls.

Roof: It is formed by thin bone from the petrous part of the temporal bone. It separates the middle ear from middle cranial fossa.

Floor: It is also known as jugular wall. It consists of thin layer of bone, which separates the middle ear from the internal jugular vein. Near the medial border of the floor there is a small aperture through which the tympanic branch from the glossopharyn- geal nerve (CN ix) enters the middle ear.

Anterior wall: Its lower part separate the tympanic cavity from the internal carotid artery.

Superiorly the wall is deficient by presence of a large opening for the entrance of the pharyngo tympanic tube into the middle ear and a smaller opening for the tensor tympani muscle,

Posterior or mastoid wall: It consists of bony partition between the tympanic cavity and the mastoid air cells.

Superiorly, there is a hole in this partition, allowing the two areas to communicate and this hole is known as the aditus to the mastoid antrum.

Medial or labyrinthine wall: It is formed by the lateral wall of the inner ear. A prominent structure on this wall is a rounded bulge the promontory produced by the basal coil of the cochlea, which is an internal ear structure involved with hearing.

The tympanic branch of the glossopharyngeal nerve and branches from the internal carotid plexus covering the promontory.

Two other structures associated with the medial wall are the oval window and the round window.

The oval window is postero-superior to the promontory and the point of attachment for the base of the stapes (footplate).

The round window is postero-inferior to the promontory.

Lateral wall is made up of tympanic membrane and the lateral wall of the epitympanic recess.

Ear ossicles: The bones of the middle ear are malleus, incus and stapes. They are connected in a chain like manner, linking the tympanic membrane to the oval window of the internal ear.

(a) Malleus

The malleus includes the head, neck, anterior and lateral processes and handles the malleus. It is the largest and most lateral bone of the ear ossicles, attaching to the tympanic membrane via the handle of the malleus. The head of the malleus lies in the epitympanic recess, where it articulates with the next ear ossicle; the incus. Inferior to the head is the constricted neck of the malleus and below the neck there are two processes; the anterior and lateral process. The anterior process is attached to the anterior wall of the middle ear and the lateral process is attached to the tympanic membrane.

(b) Incus

It is consists of body and two limbs; short and long limbs. Body articulates with the malleus bone and the short limb attaches to the posterior wall of the middle ear. The long limb joins with the stapes.

(c) Stapes

It is the smallest bone of the human body. It has head, two limbs and a base. The head articulates with the incus and the base joins the oval window.

Muscles of the middle ear: There are two muscles which serve a protective function in the middle ear. These are tensor tympani and the stapedius muscles.

Nose- The nose is a visible component of the face. It is respiratory passage and also the organ of smell. The nose is divided into two parts-1. The external nose 2. Nasal cavity.

External nose- The external nose is pyramidal in shape. Nasal root is located superiorly and is continuous with forehead. The apex of the nose ends inferiorly in a rounded ‘tip’. Spanning between the root and apex is called dorsum of the nose. Located immediately inferiorly to the apex are the nostrils. The nostrils are bounded medially by nasal septum and laterally by ala of nose. Anatomically structure of the external

nose: External nose is made up of both bony and cartilaginous component. Bony component: It is located superiorly and is comprised of-

Nasal bone   Maxillae bone  Frontal bone

Cartilaginous component: It is located inferiorly and is comprised of two lateral alar cartilages and one medial septal cartilage.

Skin over the bony part of the nose is thin and over the cartilaginous part is thicker with many sebaceous glands. Skin extends into the vestibule of the nose via nostrils and there are hairs which have functions to filter air as it enters the respiratory 2. Nasal cavity: The nasal cavity has four functions- Warms and humidifies the inspired air. Removes and traps pathogens from inspired air. Responsible for sense of smell. Drains and clears the paranasal sinuses and lacrimal ducts.

Nasal cavity is most superior part of the respiratory tract. It extends from vestibule of the nose to the nasopharynx and has three divisions-

Vestibule: It is the area surrounding the anterior external opening to the nasal cavity.  Respiratory region: It is lined by mucus secreting goblet cells. It is highly vascular and warms the inspired air. Olfactory region: It is lined by olfactory receptors for smell and placed in the upper 1/3 of nasal cavity. Division of the nasal cavity: Nasal cavity is divided into two halves by nasal septum. Each half of the nasal cavity has roof, floor, lateral and medial walls. Roof: The cribriform plate of ethmoid bone forms the roof of the nasal cavity. It is 2mm wide. Floor: It is formed by horizontal plate of palatine bone and the palatine process of the maxilla. It is 2cm wide. Lateral wall: The lateral wall of the nasal cavity is projecting out three irregular bony projections called conchae.

Blood supply: Nose has very rich blood supply and receives blood from following arteries-

Sphenopalatine artery Greater palatine artery Superior labial artery Lateral nasal arteries The anterior ethmoidal artery The posterior ethmoidal artery

The tongue is a muscular organ located on the floor of your mouth. It’s a busy and complex part of your body, responsible for taste, speech, swallowing, and more. Here’s a breakdown of its key anatomical parts:

Main Parts of the Tongue

Tip (Apex): The movable front part of the tongue.

Body: The largest part of the tongue, containing most of the taste buds. It can be further divided into the anterior (front) and posterior (back) sections.

Dorsum (Superior Surface): The upper surface of the tongue, rough and covered in papillae (bumps) containing taste buds.

Speech: The tongue helps shape the sounds we make when we speak. By moving the tongue against the teeth and palate, we can produce different sounds.

Swallowing: The tongue plays a crucial role in moving food from the mouth to the esophagus during swallowing.

Oral Hygiene: The tongue helps keep your teeth clean by scraping food particles off them.

Circumvallate papillae: V-shaped papillae arranged in a row near the back of the tongue, containing taste buds for all five tastes (sweet, salty, sour, bitter, and umami).

Foliate papillae: Leaf-shaped papillae located along the sides of the back of the tongue, containing some taste buds.

Taste Buds: Tiny sensory organs located within the papillae that detect taste. Each taste bud contains taste receptor cells that respond to different taste sensations.

Functions of the Tongue Taste: The tongue is the primary organ of taste. Taste buds detect five basic tastes: sweet, salty, sour, bitter, and umami. Speech: The tongue helps shape the sounds we make when we speak. By moving the tongue against the teeth and palate, we can produce different sounds. Swallowing: The tongue plays a crucial role in moving food from the mouth to the esophagus during swallowing.

Oral Hygiene: The tongue helps keep your teeth clean by scraping food particles off them.

Nerve supply: All the intrinsic and extrinsic muscles except palatoglossus are supplied by the hypoglossal nerve (CN XII). Palatoglossus muscle is supplied by the vagus nerve (CNX).

Blood supply: The major artery of the tongue is the lingual artery branch of the external carotid artery. The tongue is also supplied by the tonsillar artery which is the branch of facial artery.

Glossiti, thrush, carcinoma

Right atrium: The right atrium receives

deoxygenated blood from superior vena cava, inferior vena cava and coronary veins. It pumps this blood through the right atrioventricular orifice which is guarded by tricuspid valve into right ventricle. The right atrium forms the right border of the heart.

External features of right atrium

Upper end is prolonged to the left to form right auricle. Auricle covers the root of ascending aorta.

Right atrium is elongated vertically, receiving the superior vena cava at the upper end and the inferior vena cava at the lower end.

On the external surface of the right atrium, there is a vertical groove which passes from superior vena cava to inferior vena cava. This groove is called sulcus terminalis. Upper part of the sulcus contains SA node which act as pacemaker of the heart.

The right atrium and the right ventricle are separated by atrioventricular groove which is also called the coronary sulcus.

Tributaries of right atrium

Superior vena cava

Inferior vena cava

Coronary sinus: It lies in the right atrium between be fossa ovalis and opening of IVC. It is largest vein of the heart.

Venae cordis minimi: Also called thebasian veins are small cardiac vein present in all the four chambers of heart and empty mostly into the right atrium.

Internal features of the right atrium: Internally right atrium divided into 2 main parts-

Anterior rough part or atrium proper. The wall of the atrium proper shows the presence of a number of transversely muscular ridges called musculi pectinati. The right atrium is separated from left atrium by the interatrial septum. Lower Part of the septum shows on oval depression called the fossa ovalis. The margin of the fossa is thickened and called the limbus fossa ovalis.

Posterior smooth part or sinus venarum. The sinus venarum is embryologically derived from the sinus venosus. The sinus venarum and the atrium proper meet along a vertical line on the internal surface of the right atrium. It is called crista terminalis. The position of the crista terminalis is similar to the position of sulcus terminalis which is present on the external surface of the atrium.

Right Ventricle: The right ventricle forms the inferior border and sternocostal surface of the heart.

It is most anterior of the four chambers and receives deoxygenated blood from right atrium through the right atrioventricular orifice and pumps it into the pulmonary circulation by pulmonary artery. The interior of right ventricle has two parts-

Inflowing part: It is in front of the right atrioventricular orifice and has rough inner sur- face due to presence of cardiac muscle called trabeculae corneae. The Trabeculae corneae (supporting beam) are of three types-

Ridges or fixed elevations from the ventricle wall.

Bridges: It is attached at their ends to the ventricular wall but free in the middle (like bridge).

Pillars or papillary muscle with one end attached to ventricle wall and other end connected to the cusps of tricuspid valve by chordae tendineae. The right ventricle has 3 papillary muscles. Out flowing part: It is smooth and conical which give rise to the Pulmonary trunk.

Stomach is an intraperitoneal digestive organ located between the oesophagus and the duodenum. It is also called the gaster.

Stomach is muscular bag and most distensible part of the digestive tract and it is about 25cm long. Location: Stomach occupying the epigastrium, umbilical and left hypochondrium regions. Shape: Stomach is J shaped  Capacity: At birth is 30ml, at puberty – 1 liter and in adults it is about 2 liter. Division of Stomach: The stomach has four main anatomical divisions- 1. Cardia: It surrounds the superior opening of the stomach. Lower part of oesphagus joined with this part of stomach. It is 2.5 cm left from the midline at the level of 7th costal cartilage (T, vertebra).  2. Fundus: The highest part of the stomach is fundus. It is rounded, often gas filled portion superior to and left of the cardia. 3. Body: Body is large central portion inferior to the fundus. It is above and to the left of the incisura angularis. 4. Pylorus: This area connects the stomach to the duodenum. It is divided into pyloric antrum, pyloric canal and pyloric sphincter.  The pyloric sphincter demarcates the transpyloric plane at the level of L, vertebra. Pyloric sphincter controls of the exit of chyme (food + acid) from the stomach. Pyloric antrum is the dilated part of the pylorus and pyloric canal is the narrower right part of the pylorus.

External Features: Stomach has 2 curvatures and 2 surfaces. Two curvatures Greater curvature: It forms long, convex lateral border of stomach. It provides attachment to the greater omentum. Lesser Curvature: It forms shorter, concave and medial border of the stomach. It provides attachment to lesser omentum. It is more or less J shaped and has a dependent part called the incisura angularis. Two surfaces Anterior surface of the stomach is related to- the diaphragm, Left lobe of liver and the anterior abdominal wall Posterior surface: faces backwards and downwards. Posterior surface of the stomach is related to the structure forming the stomach bed. These structure are Diaphragm, Pancreas, Splenic artery, Splenic flexor colon, Left kidney, Left suprarenal gland, Transverse mesocolon.

Interior of the stomach: The stomach has to be opened to see its inner structures. The interior of the stomach is divided into following three coats:

Mucosa coat: The stomach has ability to expand or contract depending upon the amount of food contained within it. When contracted, the interior walls form 

numerous fold called rugae, which disappear when the walls become distended. Submucous coat: It is made up of connective tissue.  Muscle coat: It is made up of outer longitudinal layer, middle circular layer and Inner oblique layer. 

Blood Supply of the stomach: The arterial supply to the stomach comes from the celiac trunk which is the direct branch of the abdominal aorta. The anastomoses form along the lesser curvature by right and left gastric arteries and along greater curvature by right and left gastroepiploic arteries. Right gastric artery is the branch of common hepatic artery, which arises from the celiac trunk. Left gastric artery is arises directly from the celiac trunk. Right gastroepiploic artery is the terminal branch of the gastroduodenal artery which arise from common hepatic artery. Left gastroepiploic artery is the branch of the splenic artery, which arise from the celiac trunk.

स्त्रातस- मूलस्थान (चरक) -मूलस्थान (सुश्रुत)

प्राणवह स्त्रोतस –हृदय महास्त्रोतस-हृदय, रसवह धमनियां

अन्नवह स्त्रोतस-आमाशय, वामपार्शव-आमाशय, अन्नवह धमनियां

उदकवह स्त्रोतस-तालु, क्लोम-तालु, क्लोम

रसवह स्त्रोतस-हृदय, दशधमनियां-हृदय, रसवह धमनियां

रक्तवह स्त्रोतस-यकृत, त्लीहा-यकृत, त्लीहा, रक्तवह धमनियां

मांसवह स्त्रोतस-स्नायु, त्वचा-स्नायु, त्वचा, रक्तवह धमनियां

मेदोवह स्त्रोतस- वृक्क, वपावहन-कटि, वृक्क

अस्थिवह स्त्रोतस-मेद, जघन – – 

मज्जावह स्त्रोतस- अस्थि, सन्धि – –

शुक्रवह स्त्रोतस- वृषण, शेफ- वृषण, स्तन्य

मूत्रवह स्त्रोतस- बस्ति, वंक्षण-बस्ति, मेढू

पुरीषवह स्त्रोतस-पक्वाशय, स्थूलगुद-पक्वाशय, गुद

स्वेदवह स्त्रोतस – मेद, लोमकूप- –

आर्तववह स्त्रोतस- –  -गर्भाशय, आर्तववह धमनियां

Duodenum is the most proximal portion of the small intestine. It runs from the pylorus of the stomach to the duodenojejunal junction. Its name is derived from the latin ‘duodenum digitorum’ meaning twelve fingers.

Parts: The duodenum is divided into 4 parts; first, second, third and fourth part. Together these parts form a ‘C’ shape, that is around 25cm long and wraps around the head of the pancreas.First part of the duodenum: The first part of the duodenum is 5 cm long and continues from the pylorus, ascend upwards to meet the second part at superior duodenal flexor. First part of the duodenum is mobile and connected to the liver by hepatoduodenal ligament of the lesser omentum. Proximal 3cm of the duodenum is covered anteriorly and posteriorly by visceral peritoneum and remain- ing duodenum is retroperitoneal (only covered anteriorly). Anterior relations of the 1″ part- Gall bladder. Quadrate lobe of liver. Posterior relations of the 1″ part- Bile duct. Inferior vena cava. Portal vein. Superiorly the first part of the duodenum is related to hepatoduodenal ligament (lesser omentum). Inferiorly the first part is related to head and neck of the pancreas. Second part of the duodenum: It is 8 cm long and retroperitoneal. It begins from superior duodenal flexor passes downwards, turn left at inferior duodenal flexor and continuous with third part. It extends from L1 to L3 vertebrae. The pancreatic duct and common bile duct enter the second part of duodenum through major duodenal papilla. 2cm above the major duodenal papilla there is smaller projection called the minor duodenal papilla. The minor duodenal papilla has an opening for accessory pancreatic duct. Anterior relations of the 2nd part- Right lobe of liver. Transverse colon and transverse mesocolon. The coils of jejunum. Posterior relations of the 2nd part- Anterior surface of right kidney. Right renal vessels. Inferior vena cava. Right psoas major muscle. Medial relations of the 2nd part- The head of the pancreas. Bile duct.  Pancreatic duct. Third part of the duodenum: It is a horizontal part begins from inferior duodenal flexure and ends by joining the fourth part. It is about 10 cm long and crosses the midline at the level of the third lumbar vertebra. Anterior relations of the 3rd part- Superior mesenteric artery Superior mesenteric vein Transverse colon and transverse mesocolon. Posterior relations of the 3rd part- Right psoas major muscle Inferior vena cava Abdominal aorta Right ureter Superiorly it is related to the pancreas and inferiorly with the coils of jejunum. Fourth part of the duodenum: It is ascending part of the duodenum passes upward joining with jejunum at the duodeno- jejunal flexure. It is about 3cm long.

Anterior relations of the 4th part- Transverse colon Transverse mesocolon Posterior relations of the 4th part- Left psoas major muscle Left renal vessels Left testicular vessels Superiorly it is related to the body of pancreas and inferiorly with the coils of jejunum. Blood supply

Proximal to major duodenal papilla is supplied by superior pancreatoduodenal artery. Distal to major duodenal papilla is supplied by inferior pancreatoduodenal artery. Veins of the duodenum drain into the splenic and portal veins.

Clinical anatomy Duodenal obstruction. Duodenal ulcer

Liver is called “hepar” from which we have adjective “hepatic”.

Liver is an accessory digestive gland, performs a wide range of functions, such as synthesis of bile, glycogen storage and clotting factor production.

Definition Liver is a large, solid, endocrine gland. Liver is largest gland in body. Liver is soft, consistency and very friable.

Colour Reddish brown

Shape: Wedge shape and resembles four- sided pyramid laid on one side.

Weight About 1600gm in male About 1300gm in female

Location: Situated in the right upper quadrant of the abdominal cavity. The liver is located in the right hypochondrium, epigastrium, left hypochondrium and the upper part of right lumbar region. From above liver is covered with ribs and costal cartilages, expect in epigastric region where it is contact with anterior abdominal wall.

External features: It has five surfaces and one prominent sharp inferior border- 1. Anterior surface 2. Posterior surface 3. Superior surface 4. Inferior surface 5. Right surface

Inferior border: It is a sharp anteriorly where it separates the anterior surface from inferior surface. It is rounded laterally where it separates the right surface from inferior surface. The sharp anterior part is marked by- 1. An interlobar notch or notch for the ligamentum teres. 2. Cystic notch for the fundus of gall bladder In epigastrium region the inferior border extends from the left 8th costal cartilage to the right 9th costal cartilage.

1. Right Lobe: 5/6 Part of Liver- Much larger than left lobe From 5/6 part of liver and it contribute to all five surfaces. It presents caudate lobe and quadrate lobe. Caudate lobe: It is situated on the posterior surface. Caudate lobe is bounded on its- Right side by groove for inferior vena cava (IVC). Left side by fissure for ligamentum venosum (remnant of ductus venosus)  Inferiorly by porta hepatis. Above it is continues with the superior surface of the liver. Below and to the right just behind the porta hepatis, it is connected to the right lobe the liver by the caudate process Below and to the left it present a small rounded elevation called the papillary process.

Quadrate lobe It is situated on the inferior surface of the liver It is rectangular in shape Left lobe of the liver is much smaller than the right lobe. Its inferior surface present round elevation called tuber omentale or omental tuberosity.

Porta Hepatis- The porta hepatis is the “hilum’ of the liver. It is deep, transverse fissure and size about 5 cm long. Location: Situated on the inferior surface of the right lobe. It lies between caudate lobe above and quadrate lobe below and in front.

Structures entering into porta hepatis are- (a) Portal vein (b) Hepatic artery (c) Hepatic plexus of nerve Structures coming out from porta hepatis are- (a) Right and left hepatic duct. (b) Hepatic lymph. (c) Hepatic vein Structures from behind forwards- (a) Portal vein

(b) Hepatic artery (c) Hepatic duct. Lip of porta hepatis provides attachment to the lesser omentum.

2. Left Lobe: 1/6TH Part of Liver Much smaller than right lobe Forms 1/6th part of liver It is flattened from above downwards Near the fissure for the ligamentum venosum its inferior surface presents a rounded elevation called omental tuberosity or tuber omentale.

Blood supply: Liver receives more venous blood than arterial blood and this is due to fact that liver helps to clean blood via detoxification. Liver receives 20% of its blood supply through hepatic artery and 80% through the portal vein. Hepatic artery is the branch of the celiac trunk. The hepatic artery enter into the liver through porta hapatis and divides into two main branches for right and left lobe of liver. Portal vein also enter through the porta hepatis and divides into right and left branches, which accompany the branches of the hepatic artery. Blood from the liver is drained by hepatic vein which open directly into the inferior vena cava.

The spleen is a wedge-shaped organ lying mainly in the left upper quadrant (left hypochondrium and partly in the epigastrium) and is protected by the left 9th to 11th ribs. It is soft, highly vascular and dark purple in color.

Size and weight vary from person to person but on average, the spleen is around 2.5 cm thick, 7.5 cm broad and 12 cm in length. Its volume is on average between 100 to 300 cm 3,12. For pediatric measurements, see the article spleen size (pediatric)

The spleen has two poles (superior and inferior), three borders (superior, inferior and intermediate) and two surfaces (diaphragmatic and visceral). It is enclosed by a thin capsule, which is easily ruptured.  The diaphragmatic surface contains impressions from the 9th to 11th ribs. The visceral surface has three impressions – these are the gastric area for the stomach, the colic area for the splenic flexure of the colon and the renal area for the left kidney. The spleen is completely covered by peritoneum, except at the hilum, which forms a number of ligaments 6,7:

gastrosplenic ligament attaches the spleen to the greater curvature of the stomach contains short gastric and left gastroepiploic arteries

splenorenal ligament attaches the spleen to the left kidney contains splenic artery and vein and the pancreatic tail

Relations

diaphragmatic surface (superoposteriorly): dome of the left hemidiaphragm, left 9th to 11th ribs visceral surface-  pancreatic tail – medial  left kidney and adrenal gland – posteromedial  greater curvature and fundus of stomach – anteromedial  splenic flexure of the transverse colon – inferior A normal spleen may indent the cardia of the stomach. The fundus of the stomach may be indented by spleneculi or ectopic spleen   : splenic artery SPLENOMEGALY, SPLINC PUNCHER

The pancreas is located at approximately the L1-L2 vertebral level in the anterior pararenal space of the retroperitoneum with the exception of its tail, which is intraperitoneal. It is an elongated, mostly midline structure that extends further left laterally. It lies slightly oblique with its tail more superior to its head. Developmentally, it is considered a secondary retroperitoneal structure 6.

The diameter of the pancreatic head does not exceed the transverse diameter of the adjacent vertebral body 9.

Structure
The pancreas may have the shape of a dumbbell, tadpole, or sausage. It can be divided into four main parts:

head: thickest part; lies to the right of the superior mesenteric vessels neck: thinnest part; lies anterior to SMA, SMV body: main part; lies to left of SMA, SMV tail: lies between layers of the splenorenal ligament in the splenic hilum and is the only intraperitoneal part

Pancreatic juice is secreted into a branching system of pancreatic ducts that extend throughout the gland. In the majority of individuals, the main pancreatic duct empties into the second part of duodenum at the ampulla of Vater.

Function The pancreas is involved in production of endocrine hormones, including insulin, glucagon, and somatostatin. Its exocrine function is secretion of enzymes involved in the break down of carbohydrates, proteins and lipids.

Relations posterior L1/L2 vertebral body, right kidney hilum, portal vein, and IVC behind head common bile duct grooves posterior surface of upper part of head close to duodenum aorta behind neck and uncinate process  left kidney hilum, left suprarenal gland splenic vein joined by inferior mesenteric vein, and confluence of splenic vein and superior mesenteric vein to form portal vein anterior lesser sac separating it from stomach, lesser omentum and liver through it above the lesser curvature attachment of transverse mesocolon across head and lower margin of neck and body, D1 duodenum anterior to (or above) head of pancreas, infracolic compartment in front of lower part of head, neck and body superior origin of celiac trunk, common hepatic artery runs to the right across upper margin of head and neck, splenic artery runs to the left across upper margin of body   Arterial supply- Arterial supply to the head is primarily from the inferior and superior pancreaticoduodenal arteries. Branches of the splenic artery supply the neck, body and tail via multiple branches including the dorsal pancreatic artery, greater pancreatic artery (arteria pancreatica magna) and transverse pancreatic artery.

The kidney is bean-shaped with a superior and an inferior pole, anterior and posterior surfaces, and lateral and medial borders. The midportion of the kidney is often called the midpole.   The kidney has a fibrous capsule, which is surrounded by perirenal fat. The kidney itself can be divided into renal parenchyma, consisting of renal cortex and medulla, and the renal sinus containing renal pelvis, calyces, renal vessels, nerves, lymphatics and perirenal fat. The renal parenchyma has two layers: cortex and medulla. The renal cortex lies peripherally under the capsule while the renal medulla consists of 10-14 renal pyramids, which are separated from each other by an inward extension of the renal cortex called renal columns. Urine is produced in the renal lobes, which consists of the renal pyramid with the associated overlying renal cortex and adjacent renal columns. Each renal lobe drains at a papilla into a minor calyx, four or five of these unite to form a major calyx. Each kidney normally has two or three major calyces, which unite to form the renal pelvis. The renal hilum is the entry to the renal sinus and lies vertically at the anteromedial aspect of the kidney. It contains the renal vessels and nerves, fat and the renal pelvis, which typically emerges posterior to the renal vessels, with the renal vein being anterior to the renal artery. Filter the blood to remove excess water, minerals, and waste products of protein metabolism, producing urine in the process are involved in blood pressure regulation regulation of body fluid volume, osmolality and pH vitamin D and red blood cell (RBC) production Relations -posterior –  diaphragm and associated parietal pleura (upper pole of kidney), 11th rib (left kidney only), 12th rib (both kidneys),  medial and lateral arcuate lines, psoas major, quadratus lumborum, transversus abdominis (medial

to lateral) , subcostal nerve, iliohypogastric nerve, anterior-  ​right kidney right lobe of the liver hepatorenal recess (Morison’s pouch), D2 duodenum (medial margin of the kidney) ,right colic flexure (just above inferior pole) ,left kidney, stomach, omental bursa/lesser sac (upper pole) ,spleen (lateral margin),tail of the pancreas (hilum) ,left colic flexure (lateral to lower pole), superior, adrenal glands

the bladder has a triangular shape with a posterior base (fundus), superior dome, anterior apex, and an inferior neck with two inferolateral surfaces 6. It is lined with a rough, trabeculated transitional cell epithelium, except at the trigone 6.

The apex of the bladder is directed behind the symphysis pubis 6, connected to the anterior abdominal wall and umbilicus through the median umbilical ligament (remnant of the embryological urachus) 6, which is covered by the median umbilical fold formed by the overlying peritoneum. The trigone is a triangular area of smooth mucosa lined by stratified squamous epithelium on the internal surface of the base. The superolateral angles are formed by the ureteric orifices and the inferior angle is formed by the internal urethral orifice. As men age, the trigone overlying the mid-portion of the central zone of the prostate may start to protrude as the prostate enlarges forming a mild hemispherical elevation proximal to the internal urinary sphincter, which is called the uvula of the bladder 5. The urethra arises from the neck of the bladder and is surrounded by the internal urethral sphincter. The urethra is separated from the symphysis pubis by retropubic fatty space of Retzius .As the bladder fills with urine it becomes ovoid and extends superiorly into the abdominal cavity 6. Contraction is facilitated by the detrusor muscle. The peritoneum over the bladder is relatively loose except at the insertion points of the ureters at the posterior bladder and at the inferior bladder where the peritoneum condensed into pelvic fascia and attached to the pubic bone (pubovesical ligament in females and puboprostatic ligament in males), lateral walls of pelvis and rectum. This makes the inferior part of the bladder relatively fixed. In males, the peritoenum is reflected between the rectum and bladder to form the rectovesical pouch. In females, there are two reflections namely rectouterine pouch (pouch of Douglas) and vesicouterine pouch .Arterial supply upper part in both males and females: superior vesical artery lower part: males: inferior vesical artery females: vaginal artery All of which are branches from the anterior division of the internal iliac artery.

विषमस्पन्दन यत्र पीड़िते रुक च मर्म तत्। (अ.ह.शा. 4/37)

शरीर के जिन स्थानों पर (स्पन्दन) दबाने से अत्यंत पीड़ा होती है मर्म कहलाते हैं।

मारयन्तीति मर्मणि। (डल्हण)

जिसके कारण मृत्यु होती है मर्म कहलाते है। परन्तु शरीर में जितने मर्म है, उन पर आद्यात लगने से सभी मर्मों से मृत्यु नहीं होती इसलिए अचार्य अरूण दत्त ने कहा है

अपि च मरणकारित्वान्मर्मः मरणवत् दःखदायित्वात् वा इति।

मृत्यु के समान दुख देने के कारण ही इन स्थानों को मर्म कहा जाता है। कुछ मर्म अघात अथवा चोट लगने से पीड़ा उत्पन करते है, कुछ मर्म विकलांगता उत्पन करते है तथा कुछ मर्मों पर अद्यात लगने से कुछ समय के पश्चात् मृत्यु हो जाती है।

मर्माणि शल्य विषयार्ध। (सु.शा. 6/35)

शल्य चिकित्सक को शरीर के सम्पूर्ण मर्मों का ज्ञान होना अति आवश्यक है क्योंकि शल्य कर्म करते समय मर्म प्रदेशो को बचाना चाहिये। इसीलिए मर्म शल्य विषय का अर्थ भाग कहलाते हैं।

संख्या- सप्तोत्तरं मर्मशतम्।(सु.शा 6/3)

मर्म 107 होते हैं।

शाखा = 11×4=44 मध्य शरीर = 26 उर्ध्वजत्रुगत = 37 कुल = 107

अधोः शाखा के मर्म – 11

विटप मर्म लोहिताक्ष मर्म उर्वी मर्म आणि मर्म जानु मर्म इन्द्रबस्ति मर्म गुल्फ मर्म कूर्चशिर मर्म कूर्च मर्म तलहृदय मर्म  क्षिप्र

इसी प्रकार दूसरे पैर में।

उर्ध्वः शाखा के मर्म

गुल्फ मर्म के स्थान पर मणिबंध मर्म, जानु मर्म के स्थान पर कूर्पर मर्म, विटप मर्म के स्थान पर कक्षधर मर्म

अन्य सब, अधोः शाखा के मर्मों के सामान होते है। इस प्रकार उर्ध्व तथा अधोः शाखा में कुल 44 मर्म होते हैं।

मध्य शरीर = 2 6

उदर व उर में – 12

1 हृदय मर्म, 1 बस्ति मर्म 1 नाभि मर्म,  1 गुद मर्म, 2 स्तनमूल मर्म,   2 स्तनरोहित मर्म,  2 अपलाप मर्म,  2 अपस्तम्भ मर्म

पृष्ठ में – 14

2 कटीकतरुण मर्म, 2 नितम्ब मर्म, 2 बृहती मर्म, 2 असंफलक मर्म, मर्म शारीर, 2 कुकुन्दर मर्म, 2 पाश्व सन्धि मर्म, 2 अंस मर्म,

उर्ध्वजत्रुगत मर्म – 37

2 नीला मर्म, 2 मन्या मर्म, 8 मातृका मर्म, 2 विधुर मर्म, 2 अपांग मर्म, 2 कृकाटिका मर्म, 2 फण मर्म, 2 आवर्त मर्म, 2 उत्क्षेप मर्म, 2 शंख मर्म, 5 सीमन्त मर्म, 4 श्रृङ्गाटक मर्म, 1 स्थपनी मर्म, 1 अधिपति मर्म

इस प्रकार मध्य शरीर के कुल 37 मर्म होते हैं।

रचनानुसार मर्मों के प्रकार

रचनानुसार मर्मों के 5 प्रकार बताये गये हैं-

1. मांस मर्म-11 इन्द्रबस्ति मर्म – 4, तलहृदय मर्म – 4 ,गुद मर्म – 1 ,स्तनरोहित मर्म – 2

2. सिरा मर्म-41 अपांङ्ग मर्म – 2, नीला मर्म – 2, लोहिताक्ष मर्म – 4, मन्या मर्म – 2, फण मर्म – 2, मातृका – 8, अपलाप मर्म – 2, हृदय मर्म – 1, अपस्तम्भ मर्म – 2, नाभि मर्म 1, पार्रवसन्धि मर्म – 2, उर्वी मर्म – 4, बृहती मर्म – 2 , श्रृंगाटक मर्म 4 , स्तनमूल मर्म – 2 , स्थपनी मर्म – 1

3. स्नायु मर्म-27 विटप मर्म – 2, आणि मर्म – 4, कक्षधर मर्म – 2, छिप्र मर्म – 4, विधुर मर्म – 2, बस्ति मर्म – 1,, अंस मर्म – 2, उत्क्षेप मर्म – 2, कूर्च मर्म – 4, कूर्चशिर मर्म – 4

4. अस्थि मर्म-8 कटीकतरुण मर्म – 2, नितम्ब मर्म – 2, अंसफलक गर्म – 2, शंख मर्म – 2

5. सन्धि मर्म-20 सीमन्त मर्म – 5, कूर्पर मर्म – 2, अधिपति मर्म – 1, जानु मर्म – 2, मणिबंध मर्म – 2, गुल्फ मर्म – 2, कृकाटिका मर्म – 2, वृत मर्म – 2, कुकुन्दर मर्म – 2

परिणाम भेद से मर्मों के प्रकार मर्मों पर अघात, चोट आदि लगने से उनमें पीड़ा होगी, मृत्यु या विकलांगता होगी इनके अनुसार भी परिणाम भेद से मर्मों के 5 प्रकार बताये गये है।

परिणामानुसार मर्म

सघः प्राणहर मर्म- 19, आग्नेय महाभूत प्रधान होते है। इन पर आघात लगने से 7 दिन के भीतर व्यक्ति की मृत्यु हो जाती है।

हृदय मर्म – 1, बस्ति मर्म – 1, नाभि मर्म – 1, गुद मर्म – 1, अधिपति मर्म – 1, मातृका मर्म – 8, शंख मर्म – 2, श्रृंगाटक मर्म – 4

कालान्तर प्राणहर मर्म 33, आग्नेय तथा सौम्य महाभूत प्रधान होते हैं। इन पर आघात लगने से 15 दिन अथवा 1 मास में व्यक्ति की मृत्यु हो जाती है।

स्तनमूल मर्म – 2, स्तनरोहित मर्म – 2, अपलाप मर्म – 2, अपस्तम्भ मर्म – 2, कटीकतरुण मर्म – 2, नितम्ब मर्म – 2, पार्रवसन्धि मुर्म – 2, बृहति मर्म – 2, छिन मर्म – 4, तलहृदय मर्म – 4, इन्द्रबस्ति मर्म – 4, सीमन्त मर्म – 5

इस प्रकार कालान्तर प्राणहर मर्म कुल 33 होते हैं।

वैकल्यकर मर्म – 44 सौम्य महाभूत प्रधान होते हैं। इन पर आघात लगने से विकलांगता उत्पत्र होती है।

लोहिताक्ष मर्म – 4, आणि मर्म – 4, विधुर मर्म – 2, ककृाटिका मर्म – 2, अंस मर्म – 2, असंफलक मर्म – 2, जानु मर्म – 4, उर्वी मर्म – 4, कूर्च मर्म – 4, अपांङ्ग मर्म – 2, विटप मर्म – 2, नीला मर्म – 2, कूर्पर मर्म – 2, मन्या मर्म – 2, कुकुन्दर मर्म – 2, फण मर्म – 2, आवर्त मर्म – 2, कक्षधर मर्म – 2

*विशल्यध्न मर्म – 3 वायु महाभूत प्रधान होते हैं। इन मर्मों पर आघात लगने से जब तक शल्य मर्मों के मुख में रहेगा तब तक प्राणी जीवित रहता है किन्तु शल्य निकलने से मर्मस्थान से वायु निकल जाती है तथा व्यक्ति की मृत्यु हो जाती है।

उत्क्षेप मर्म – 2, स्थपनी मर्म – 1 

रुजाकर मर्म – 8 अग्नि तथा वायु महाभूत प्रधान होते है।

रुजाकर मर्मों पर आघात लगने से रुजा (पीड़ा) की उत्पति होती है।

गुल्फ मर्म – 2, मणिबंध मर्म 2, कूर्चशिर मर्म 4

मर्मों का प्रमाण • उर्वी मर्म, विटप मर्म, स्तनमूल मर्म, कूर्चशिर मर्म, कक्षधरमर्म- 1 अंगुल प्रमाण

गुल्फ मर्म, मणिबंध मर्म 2 अंगुल प्रमाण ; कूर्पर मर्म, जानु मर्म 3 अंगुल प्रमाण ;हृदय मर्म, बस्ति मर्म, नाभि मर्म, गुद मर्म, नीला मर्म, मन्या मर्म, मातृका, श्रृंगाटक मर्म, सीमन्त मर्म, कूर्च मर्म – स्वपाणितल प्रमाण (हथेली के गडद्दे के बराबर) ; शेष सभी 56 भर्म (1/2) अर्धअंगुल प्रमाण के होते हैं।

The uterus has an inverted pear shape. It measures about 7.5 cm in length, 5 cm wide at its upper part, and nearly 2.5 cm in thickness in adults. It weighs approximately 30-40 grams.

The uterus is divisible into two portions: body and cervix. About midway between the apex and base is a slight constriction known as the isthmus. The portion above the isthmus is termed the body, and that below, the cervix. The part of the body which lies above a plane passing through the points of the entrance of the uterine tubes is known as the fundus. The body gradually narrows from the fundus to the isthmus. The cavity of the body is a mere slit, flattened anteroposteriorly. It is triangular in shape:

the base being formed by the internal surface of the fundus between the orifices of the uterine tubes. the apex by the internal orifice of the uterus through which the cavity of the body communicates with the canal of the cervix. Although anatomically a part of the uterus, the uterine cervix has a different function and is associated with separate pathological entities. It is discussed in detail in a separate article.

Relations- anteriorly: bladder; uterovesical pouch posteriorly: rectum; pouch of Douglas laterally:
Broad ligament; round ligament; uterine vessels uterine tubes open into its upper part X inferiorly: uterine cavity communicates with that of the vagina

Arterial supply
uterine arteries and ovarian arteries the terminations of the ovarian and uterine arteries unite and form an anastomotic trunk from which branches are given off to supply the uterus in the impregnated uterus, the arteries carry the blood to the intervillous space of the placenta

Gross anatomy
The prostate gland is an inverted pyramid with a superior base and inferior apex. It has four surfaces: anterior, posterior, and two inferolateral surfaces. The base of the prostate is in continuity with the bladder, and the apex ends inferiorly at the urogenital diaphragm 1-3. The prostate gland surrounds the proximal urethra, traversing the prostate close to its anterior surface at the base and more centrally at the apex.

The anterior surface forms the posterior limit of the retropubic space. The prostate is connected to the pubic bone by the puboprostatic ligaments 1. Its inferolateral surfaces rest on the levator ani fascia 3. Its flat triangular posterior surface is anterior to the rectum and has a vertical median groove, which is palpable via a digital rectal exam. The rectovesical fascia (Denonvilliers fascia) separates it from the rectum 13.

The seminal vesicles are superior and posterior to the prostate gland. Their ejaculatory ducts pierce the posterior surface below the bladder 1-3 and drain into the prostatic urethra. 

The prostate gland lacks a true capsule, and the so-called prostate capsule is a pseudocapsule formed from fibromuscular tissue surrounding 3 distinct layers of fascia: the anterior, lateral, and posterior fasciae. Anteriorly and apically this pseudocapsule is deficient. Laterally the fascia fuses with the levator fascia. The prostatic venous plexus (of Santorini) lies between and passes through the pseudocapsule 1-3,9-11.

Neurovascular bundles travel posterolaterally at 5 and 7 o’clock and give off branches into the prostate at the apex and base 5.

Relations
anteriorly: pubic symphysis, retropubic space of Retzius

posteriorly: rectovesical fascia, rectum

posterosuperior: seminal vesicles

superiorly: bladder

inferiorly: urogenital membrane, urogenital diaphragm

laterally: prostatic venous plexus and levator ani

Arterial supply
prostatic branch of the inferior vesical artery, a branch of the anterior division of the internal iliac artery 13​

additional variable supply by prostatic branches from the middle rectal artery and internal pudendal artery, both of which are branches of the anterior division of the internal iliac artery