Portal vein

Centrally lies the porta hepatis (the hilum of the liver), the transverse section of the H. The lower (paraduodenal) third slope further to the right in a groove at the back of the head of the pancreas (it may even be embedded). in a tunnel of pancreatic tissue) and in front of the right renal vein.

Part eight. Pancreas

The tail of the pancreas passes forward and to the left from the front surface of the left kidney. To the left of the neck, the pancreas drains into the pancreaticosplenic nodes, which accompany the splenic artery.

Figure 5.39 CT scan of the upper abdomen, viewed from below. 1, gallbladder; 2, liver; 3, portal vein; 4, inferior vena cava; 5, pancreas; 6, spleen; 7, left kidney; 8, T12 vertebra; 9, abdominal aorta; 10, right crus of diaphragm; 11, coel

Part nine. Spleen

The splenic artery passes between the layers of the splenic ligament and divides at the hilum into two or three main branches, from which five or more branches enter the spleen. Removal of the spleen (splenectomy) essentially involves cutting its two 'pedicles', the splenic and gastrosplenic ligaments.

Part ten. Posterior abdominal wall

The anterior layer extends from the front of the iliolumbar ligament and the adjacent iliac crest to the lower border of the twelfth rib. In A, the left renal vein passes anterior to the aorta to enter the inferior vena cava.

Figure 5.43 Abdominal aorta, inferior vena cava, kidneys and suprarenal glands. (The sympathetic plexus on the front of the aorta has been omitted.)

Part eleven. Kidneys, ureters and suprarenal glands Kidneys

Persistence of one of the fetal arteries is common (30% of individuals), especially a blood vessel from the aorta to the inferior pole. It lies on the diaphragm and penetrates to the front of the right kidney.

Figure 5.50 Arterial segments of the left kidney. A shows branches of the renal artery; B, C and D indicate the segments as seen from the front, the lateral side and the back respectively

Part twelve. Pelvic cavity Bony pelvis

The muscles of the true pelvis are the obturator internus and piriformis (which are also classified as lower extremity muscles) and the levator ani and coccygeus (which together with their counterparts on the opposite side make up the pelvic floor or pelvic diaphragm). The fascia on the pelvic surface of the levator ani and coccygeus is the superior fascia of the pelvic diaphragm.

Figure 5.56 Posterior half of a coronal section of the pelvis. (The pelvic veins are not depicted.

Part thirteen. Rectum

The ureter and the main neurovascular structures on the side wall of the pelvis are preserved. The lower part of the excised sigmoid colon is seen at the top of the rectum.

Figure 5.57 Oblique axial MRI of the rectum. There is an annular carcinoma in the rectum.

Part fourteen. Urinary bladder and ureters in the pelvis Urinary bladder

A storage center in the lateral part of the pontine reticular formation exerts central control on this nucleus. It crosses the pelvic brim in the area of the bifurcation of the common iliac.

Figure 5.60 Trigone of bladder, prostate and prostatic urethra: coronal section.

Part fifteen. Male internal genital organs Prostate

The artery to the vas deferens is a branch of the superior vesical (or sometimes inferior vesical) artery. The smooth muscles of the vas and seminal vesicles receive fibers from the inferior hypogastric plexus.

Figure 5.61 Oblique axial MRI of the prostate. The transition zone is markedly enlarged by benign prostatic hyperplasia

Part sixteen. Female internal genital organs and urethra Uterus

The anterior layer of the broad ligament is bulged forward by the round ligament of the uterus just below the fallopian tube. It lies in the broad ligament below the fallopian tube and bulges the anterior layer of the ligament forward. It provides lateral stability to the cervix and is an important support for the uterus.

Part seventeen. Pelvic vessels and nerves Pelvic vessels

The vaginal artery supplies the upper part of the vagina and corresponds to the lower vesical artery in the male. Pain from the ovary can be referred along the nerve to the skin on the medial side of the thigh. Anterior to the fascia lie the lateral sacral arteries and veins in front of the sacral nerves.

Part eighteen. Perineum

In the upper third of the anal canal, the mucosa shows 6 to 10 longitudinal ridges, the anal columns. The lining of the upper part of the anal canal is embryologically derived from the cloaca, that is, the base of each fossa lies on the skin over the anal area of the perineum.

Figure 5.69 Coronal section of the anal canal and the right ischioanal (ischiorectal) fossa

Part nineteen. Male urogenital region

The deep dorsal vein of the penis drains most of the blood from the corpus callosum. It supplies the skin of the penis and glans and gives branches to the corpus cavernosum. Impulses in the genital branches of the pelvic splanchnic nerves (parasympathetic) lead to vasodilatation of the helicine arteries of the erectile tissue of the corpora cavernosa (hence the old name nervi erigentes).

Part twenty. Female urogenital region

As in the male, it contains the sphincter urethrae, deep transverse perineal muscles, nerves and vessels. The pudendal nerve and internal pudendal vessels have a similar course and distribution in the female deep perineal space and vulval region as in the male deep and superficial perineal space, but the neurovascular branches are generally smaller. Sexual arousal induces vascular dilatation and congestion in the vulva, especially the bulbs of the vestibule and glans clitoris, and is due, as in the male, to parasympathetic activity.

Part twenty-one. Pelvic joints and ligaments

From this broad area, the ligament slopes down to the medial surface of the ischium tuberosity. It has a wide base attached to the side of the lower part of the sacrum and the upper part of the coccyx. It narrows as it passes laterally, where the apex is attached to the spine of the ischium.

Figure 5.74 Ligaments of the right half of the pelvis: posterior aspect.

Part twenty-two. Summary of lumbar and sacral plexuses

Head and neck and spine

Part one. General topography of the neck

The lymph nodes of the posterior triangle and the accessory nerve lie superficially. The fascia is pierced by four cutaneous branches of the cervical plexus (large auricular, small occipital, transverse cervical and supraclavicular nerves). Anteriorly, the lower part of the sheath merges with the fascia on the deep surface of the sternocleidomastoid.

Figure 6.1 Deep cervical fascia of one half of the neck, showing its four components: the investing, pretracheal and prevertebral layers and the carotid sheath.

Part two. Triangles of the neck

Branches passing deep to the parotid gland supply the deep layer of parotid fascia. Its upper attachment is to the lower border of the body of the hyoid bone. Ansa cervicalis lies anterior to the internal jugular vein and gives branches to the infrahyoid muscles.

Figure 6.4 Right lower face and posterior triangle of neck. The fat in the lower part of the triangle overlies deeper structures

Part three. Prevertebral region Prevertebral muscles of the neck

The cervical portion of the sympathetic trunk (Fig. 6.8) rises from the thorax over the nape of the first rib medially to the highest intercostal vein. It runs medial to the vertebral artery and lies in front of the prevertebral fascia, behind the carotid sheath and medial to the vagus nerve. The middle cervical ganglion is a small, inconstant ganglion that lies medial to the carotid tuberculosis (C6 vertebra) and anterior to the inferior thyroid artery.

Part four. Root of the neck

Occasionally, the phrenic nerve may run anterior to the subclavian vein or posterior to the internal thoracic artery.). The base of the space is formed by the subclavian artery, which lies on the suprapleural membrane. The thyrocervical trunk arises laterally from the vertebral artery from the upper surface of the subclavian artery.

Part five. Face

It is a chin skin lifter (which I sometimes bury) and. The cervical branch passes down from the lower border of the parotid gland and supplies the platysma. The forehead is supplied from the orbit by the supraorbital and supratrochlear branches of the ophthalmic artery.

Part six. Scalp

The supraorbital is larger and supplies the front of the scalp to the crown. The temporal fascia (deep temporal fascia) is attached to the upper temporal line and runs down to the upper border of the zygomatic arch. The blood supply to the muscle comes from the temporal branches of the maxillary and superficial temporal arteries.

Part seven. Parotid region

The terminal branches of the external carotid artery (superficial temporal and maxillary) leave this surface further back. Inside the gland the branches of the facial nerve are directed in different directions corresponding to them. The stylomastoid branch of the posterior auricular artery is superficial to the facial nerve and is a guide to its proximity.

Figure 6.16 Prosection of the head and neck in the Anatomy Museum of the Royal College of Surgeons of England.

Part eight. Infratemporal region Infratemporal fossa

The larger deep head arises from the medial (deep) surface of the lateral pterygoid plate. They are distributed to the molars and the mucosa of the maxillary sinus. The carotid canal lies immediately anterior to the jugular foramen (which lies deep to the external acoustic meatus).

Figure 6.20 Left pterygoid muscles and related structures.

Part nine. Pterygopalatine fossa

It passes through the pterygomaxillary fissure to the posterior wall of the maxilla (see p. 364). They pass back to the soft palate and the mucous membrane of the palatine tonsil. The maxillary artery passes through the pterygomaxillary fissure, enters the pterygopalatine fossa anterior to the ganglion, and gives off five branches.

Figure 6.27 Right trigeminal and geniculate ganglia, petrosal nerves and pterygopalatine and otic ganglia, from the right

Part ten. Nose and paranasal sinuses

The anterosuperior part of the lateral wall is formed by the nasal bone and the frontal process of the maxilla. It anastomoses with the septal branch of the upper labial (entering through the nostril) and the ascending branch of the greater palatine (entering through the incisive canal) forming Kiesselbach's plexus, in the lower anterior part of the septum (Little's area), common site for epistaxis (nosebleeds). It opens in the posterior part of the infundibulum in the middle meatus of the lateral wall of the nose.

Figure 6.28 Left maxilla, from the medial side.

Part eleven. Mouth and hard palate

From the hard palate, the mucous membrane bends down to the lower surface of the soft palate. A small median septum of mucosa (lingual frenulum) unites it with the floor of the mouth. The sensory supply of the mucous membrane of the mouth part (anterior two thirds), but not the area of the vallate papillae, is through the lingual nerve, whose trigeminal component mediates general sensibility (with cell bodies in the trigeminal ganglion) and whose chorda tympani component mediates taste (with cell bodies in the geniculate ganglion of the facial nerve).

Part twelve. Pharynx and soft palate Pharynx

The main motor nerve supply to the muscles of the pharynx is from the pharyngeal plexus. The oropharynx extends from the lower surface of the soft palate to the upper border of the epiglottis (halfway down C3 vertebral body). The floor of the fossa (lateral wall) is the lower part of the superior constrictor.

Figure 6.36 Pharynx, from behind. On the right the inferior constrictor has been removed to show the extent of the middle constrictor and the attachment of stylopharyngeus to the posterior border of the thyroid lamina.

Part thirteen. Larynx

The base articulates with the oblique shoulder at the superior border of the cricoid lamina. It is not part of the larynx, but anchors the laryngeal skeleton to the hyoid bone. The cricotracheal membrane connects the lower border of the cricoid cartilage with the first cartilaginous ring of the trachea.