Human anatamy

Angiology comprises the cardiovascular system and the lymphatic system.

Section 1 Introduction

Ⅰ. Composition

Ⅰ）Heart: a pump to maintain the flow of blood

Ⅱ）Arteries: carrying blood away from the heart to various body tissues

Ⅲ）Veins: carrying blood from capillary networks back to the heart.

Ⅳ）Capillaries: simply thin endothelial tubes with an enclosed basement membrane (exchange vessels)

Ⅱ. The Cardiovascular Circuits

Ⅰ）Systems or Greater Circulation

Left ventricle→aorta and its branches→capillaries of the body (air and material exchange)→venules→veins→superior and inferior vena cava→right atrium.

Ⅱ）Pulmonary or Lesser Circulation

Right ventricle→pulmonary trunk and its branches→capillaries of the lung (air exchange)→pulmonary veins→left atrium.

Section 2 The Heart

Ⅰ. Position of the heart

Ⅰ）It lies in the middle mediastinum within the thoracic cavity, and is enclosed by the pericardium.

Ⅱ）It is anterior to the thoracic vertebra 5 to 8, and posterior to the sternal body and costal cartilage 2 to 6.

Ⅲ）Two-thirds of it lies on the left of the median line and one-third on the right.

Ⅱ. External Morphology of the Heart

The heart is a hollow, mascular organ of a somewhat conical form and has an apex, a base, two surfaces, three borders, and three grooves.

Base: faces backwards, upwards and to the right. It is formed mainly by the left atrium, and, to a small extent, by the right atrium.

Apex: formed by the left ventricle, is directed downwards, forwards, and to the left, It is situated in the 5^th left intercostals space, 1-2cm medical to the left mid-clavicular plane (apex beat place).

Sternocostal surface (anterior surface): faces forwards and upwards, are formed mainly by the right atrium and the right ventricle, and a lesser portion of its left is formed by the left auricle and the left ventricle.

Diaphragmatic surface (inferior surface): is directed downwards and backwards, is formed by the left ventricle and the right ventricle.

Right border: formed by the right atrium.

Left border: formed chiefly by the left ventricle, and by the left auricle.

Inferior border: formed by the right ventricle and cardiac apex, is nearly horizontal.

Coronary groove: it separats the atria from the ventricle.

Anterior interventricular groove: on the sternocostal surface.

Posterior interventricular groove: on the diaphragmatic surface. The anterior and posterior interventricular grooves mark the line of separation between the ventricles, and intersect at apical cardiac notch. Atrioventricular crux is the intersecting point between the coronary groove and the posterior interventricular groove.

Ⅲ. Internal Morphology of the Heart (Cavities of the Heart)

Ⅰ）Right Atrium

1. Two portions:

Proper atrium

divided by terminal sulcus

2. Three inlets:

3. One outlet:

4. Right auricle is a triangular process towards the left. Terminal crest is a longitudinal muscular ridge and opposite to terminal sulcus. Pectinate muscles are formed by many parallel muscular ridges.

5. Interatrial septum: oval fossa is on its lower part.

Ⅱ）Right Ventricle

It can be separated into two parts, inflowing tract and outflowing tract, by the supraventricular crest.

1. Inflowing tract:

1) One inlet: right atrioventricular orifice (tricuspid valve).

2) Tricuspid valve (anterior, posterior and septal) →chordae tendineae→papillary m.

3) Trabeculae carneae: Septomarginal trabecula is a muscular band which extends from the ventricilar septum septum to the base of the anterior papillary m.

2. Outflowing tract:

1) One outlet:

Pulmonary orifice (pulmonary valve: three semilunar valve, nodules of the semilunar valve)

2) Outflowing tract→arterial cone→pulmonary orifice→pulmonary trunk.

Ⅲ）Left Atrium

1. Four inlets: The opening of the right and left pulmonary veins.

2. One outlets: Left atrioventricular orifice.

3. Left auricle: projecting forwards.

Ⅳ）Left Ventricle

It can be separated into two parts, inflowing tract and outflowing tract, by the anterior cusp of mitral valve.

1. Inflowing tract:

1) One inlet: left atrioventricular orifice (mitral valve)

2) Mitral valve(anterior and posterior) →tendinous cord→papillary m.

2. Outflowing tract:

1) One outlet: aortic orifice (aortic valve)

2) Outflowing tract: aortic vestibule→aortic orifice→aorta

3) Aortic sinuses: are three slight dilatations (right, left and posterior) between aortic cusps and aortic wall, from two of which the coronary arteries arise.

Ⅳ. Structure of the Heart

Ⅰ）Cardiac wall: comprises three layers, named from within outwards endocardium, myocardium and epicardium.

Ⅱ）Intreratial Septum and Interventricular Septum

1. Interatrial septum: slops obliquely, and divides the left and right atrium.

2. Interventricular septum: is placed obliquely.

muscular part: a greater portion

membranous part: a lesser portion

3. The skeleton of the heart (or the support framework of fibrous tissue of the heart); is composed of fibrous rings and fibrous trigones (left and right).

Ⅴ.The Conducting system of the Heart

Ⅰ）Function

1. Initiating and conducting electrical impulse.

2. Maintaining the normal cardiac rhythm.

3. Ensuring the proper coordination of the atrial and ventricular contractions.

Ⅱ）Composition

1. Sinonatrial node(SA node)

It initiates each cardiac cycle. It is situated at the junction between the right atrium and the superior vena cava. It is covered only with the epicardium and commonly called the pacemaker.

2. Atrioventricular node (AV node)

It passes sinoatrial impulse towards the ventricles, and it lies on the right side and lower part of the interatrial septum , under the endocardium, just anterosuperior to the orifice of coronary sinus.

3. Atrioventricular bundle (His bundle)

From atrioventricular node, it extends through the right fibrous trigone to the posterior margin of membranous part of the interventricular septum, and then turns forwards, at the superior margin of the muscular part, it divides into the right and left limbs.

4. Right and left limbs

They passes towards the apex immediately beneath the endocardium of each surface of the interventricular septum respectively. The left limb consists of two main strands, an anterior and a posterior.

5. Purkinje fibres

The limbs ramify a number of branches, the terminal conducting fibres or Purkinje fibres are continuous with the cardiac muscle fibres.

Ⅵ. The Vessels of the Heart

Ⅰ）Arteries

1. Right coronary artery.

It arises from the right aortic sinus, and passes between the root of the pulmonary trunk and the right auricle to the coronary groove. Following the sulcus, it runs to the diaphragmatic surface. At the atrioventricular crux, it divides into two branches---posterior interventricular branch and posterior branch of left ventricle.

The right coronary artery supplies the right atrium, right ventricle, posterior 1/3 of the interventricular septum, posterior wall of the left ventricle, the sinoatrial node and the atrioventricular node.

2. Left coronary.

It arises from the left aortic sinus, and passes forwards between the root of the pulmonary trunk and the left auricle to reach coronary groove, where it gives off the following branches.

1) Anterior interventricular branch

It descends along the anterior interentricular groove, and supplies anterior wall of the left ventricle, lesser portion of the anterior wall of the right ventricle, and anterior 2/3 of the interventricular septum.

2) Circumflex branch

It passes to the left in the coronary groove and supplies to the diaphragmatic surface of the left ventricle and the wall of the left atrium.

Ⅱ）Veins

1. Smallest cardiac veins: end directly into the cardiac cavities.

3. Coronary sinus

It situated in the posterior part of coronary sulcus between the left atrium and left ventricle, and opens into right atrium. Its tributaries are:

1) Great cardiac vein

2) Middle cardiac vein

3) Small cardiac vein

Ⅶ. Pericardium

It comprises two sacs, named the fibrous pericardium and serous pericardium.

Ⅰ）Fibrous pericardium

It is continuous with the external coats of the great vessels, while its base is attached to the central tendon of the diaphragm.

Ⅱ）Serous Pericardium

It consists of a visceral layer covering the heart and a parietal layer lining the fibrous pericardium. Between two layers, the potential space called pericardial cavity exists.

1. Transverse sinus: lies behind the commencement of the aorta and pulmonary, in front of superior vena cava and left atrium.

2. Oblique sinus: lies between the posterior wall of the left atrium, left and right pulmonary veins, inferior vena cava and posterior wall of the pericardium.

Section 3 The Arteries

Ⅰ. Arteries of Pulmonary Circulation

Ⅰ）Pulmonary Trunk

It arises from the right ventricle, at first in front of the ascending aorta, and turns upwards, backwards and to its left side. In the concavity of the aortic arch, it divides into right and left pulmonary arteries.

Ⅱ）Pulmonary Arteries

The right pulmonary artery is slightly longer and larger than the left pulmonary artery. They run horizontally to the hilus of the right and left lung respectively.

Ⅲ）Arterial Ligament

It is a fibrous cord connecting the beginning of the left pulmonary artery with the concavity of the aortic arch.

Ⅱ. Arterial of Systemic Circulation

ascending aorta

Aorta--------------------------------------------------------------------------the right second sternocostal

(passing to right, and left arise from upwards ventricle forwards)
aortic arch thoracic aorta

Joint---------------------------------------the left side of T4 vertebra--------------------------------------

(arching to the left and backwards) (descending along vertebral column)
Abdominal aorta

At anterior to T12 vertebra-----------------------------------------------------at the lower border of L4

(passing through the aortic hiatus

of diaphragm into abdominal cavity)

left common iliac artery

Vertebra----

Ⅰ）Ascending Aorta: it arises from the left ventricle at the level of the 3^rd intercostals space and behind the left margin of sternum, to reach the 2nd right sternocostal joint. It send out to branches called right and left coronary arteries.

Ⅱ）Aortic Arch: it is from the 2^nd right sternocostal joint to the inferior border of T4 vertebra. From right and left, three branches are given off from the convex aspect of aortic arch---brachiocephalic truck, the left common carotid artery and the left subclavian artery.

The brachiocephalic trunk divides into the right common carotid and right subclavian arteries at the level of the right sternoclavian joint.

1. Common carotid artery

The left one springs from the aortic arch, while the right one arises from the brachiocephalic trunk. Each passes upwards behind the sternoclavicular joint, then along the lateral to the trachea and esophagus, at the level of the upper border of the thyroid cartilage, it divides into the external and internal carotid arteries.

1) External carotid artery: Its main branches are as follows:

①Superior thyroid artery→supplying the upper part of thyroid gkand and larynx.

②Lingual artery→supplying tongue, palatine tonsil and sublingual gland.

③Facial artery→supplying submandibular gland, the structures of face, and palatine tonsil.

④Superficial temporal artery→supplying the soft tissue of frontal, temporal and parietal regions, parotid gland, orbicular muscle of eye.

⑤Maxillary artery→supplying external auditory canal, middle ear, meninges, cheek, palatine tonsil, lower and upper teeth and gums, muscles of mastication, nasal cavity, and palate.

2) Internal carotid artery: It ascends to the base of skull and enters the cranial cavity without giving off branches in the neck. This is the major artery to the brain and orbital structures.

2. Subclavian artery

The left one springs from aortic arch; the right, from brachiocephalic trunk. At the outer border of the first rib, it becomes the axillary artery. Its important branches are as following.

1) Vertebral artery→supplying the brain and spinal cord.

2) Internal thoracic artery→supplying anterior thoracic wall, pericardium, diaphragm, and upper abdominal wall.

3) Thyrocervical trunk→Its one important branches is inferior thyroid artery, which supplies thyroid gland.
3. The arteries of upper limb

Outer border of the first rib thoracoacromial a.

lower border of teres major m. subscapular a. thoracodorsal a.

the neck of radial bone posterior circumflex humeral a.

principal a. of thumb

------radial a. superficial palmar branch

terminal branch

common interosseous a. superficial

-----

terminal branch

Ⅲ）Toracic Aorta

It descends from the lower border of T4 vertebra to the lower border of T12 vertebra, where it passes though the aortic hiatus of the diaphragm and becomes the abdominal aorta. Its branches are:

posterior intercostals a.(9 pairs)

parietal branches -to 3-11 intercostal space and upper part of abdominal wall

subcostal a.-abdominal wall.

bronchial a.

visceral branches esophageal a.

pericardial a.

Ⅳ）Abdominal Aorta

It continuous with thoracic aortic hiatus of the diaphragm and ends in fronts of L4 vertebra by dividing into the left and right common illac a. The branches are as following:

inferior phrenic a.

Parietal branches

paired renal a.

single superior mesenteric a.

1. Celiac trunk

It is a short trunk just below the aortic hiatus of the diaphragm or approximately at the level of t12 vertenra.
esophageal branchabdominal part of esophagus.

Left gastric a. gastriccardiac orifice and

lesser curvature of stomach.

anastomosing

right gastic a. lesser curvature

of stomach.

proper hepatic a. left hepatc a.

right hepatic a.

common custic a. gallbladder

hepatic a. superior pancreaticoduodenal a.

pancreas, duodenum.

Ganstroduodenal a. right gastroepiploic a.

greater curvature

Of stomach, greater omentum. Anastomosing

Left gastroepiploic a.

greater curvature of stomach, greater omentum.

pancreatic branchbody of and tail of pancreas

splenic branchspleen

2. Superior mesenteric a.

It is about at the level of L1 vertebra, and passes obliquely between the head of pancreas and the horizontal part of duodenum, and enters the root of the mesentery to reach the right iliac fossa.

jejunal and ileal a. jejunum and ileum.

to ascending colon, cecum, terminal part of ileum

3. Inferior mesenteric a.

It is opposite L3 vertebra, passes downwards and to the left to reach the left iliac fossa, then terminates as superior rectal a.

left colic a. descending colon

sigmoid a. sigmoid colon

superior rectal a. rectum

Ⅴ）Common Iliac Arterty

The common of iliac artery diverge from the abdominal aorta opposite L4 vertebra. Each artery passes downwards and laterally, and ends at the level of the sacroiliac joint by dividing the external and internal iliac arteries.

1. Internal iliac artery

parietal branches superior gluteal a.

gluteal m. and hip joint

inferior gluteal a.

umbilical a. superior vesical a.--urinary bladder

inferior vesicle a.urinary bladder, prostate, seminal, vesicle, vagina

visceral branches inferior rectal a. rectum

2. External iliac artery

Each runs downwards along the medial border of psoas major m. and enters the thigh behind the inguinal ligament to become the femoral artery. One branches of it is called interior epigastric a. which anastomoses with superior epigastric a. behind rectal abdominal m. cends vertically to end the right atrium at the level of the 3th right sternocostal joint.

3.The arteries of lower limb

behind midpoint lateral circumflex femoral a.

of inguinal lig. femoral a. deep femoral a. m. of thigh and knee joint

adductor hiatus ↓ articulating medial circumflex femoral a.

lower border of popliteal a. branch m. of thigh and hip joint

popliteal m. muscular branch perforating a. m. of thigh

femur
-posterior tibial a. peroneal a. m. of leg, tibia and fibula

-anterior tibial a. dorsal pedal a.

Section 4 The Veins

ⅠVeins of Pulmonary Circulation

Pulmonary veins are four in number, two from each lung, a superior an an inferior. They return the oxygenated blood from the lungs to the left atrium of the heart.

Ⅱ. Veins of Systemic Circulation

They may be arranged into three groups.

superior vena cava system

inferior vena cava system(portal venous system)

cardiac venous system

Ⅰ）Superior Vena Cava System

The system is composed by the superior vena cava and its tributaries which collect the blood from the head and neck, the upper limb, the wall and some organs of the thorax, and the upper part of abdominal wall.

1. Superior vena cava

It is formed by the junction of right and left brachiocephalic veins just behind the first right costal cartilage close to the sternum, and des缺

2. Brachiocephalic (lnnominate) veins

It is formed, behind the sternoclavicular joint, by the union of the internal jugular and subclavian veins of its side. The angle of the union is termed the venous angle.

1) Internal jugular vein

It originates from the jugular foramen, and unites with the subclavian vein to form the brachiocephalic vein. The chief extracranial tributaries are:

① Facial vein ②Retromandibular vein

ophthalmic v. facial v.

↑

↓

↑ internal jugular v.

↓

pterygoid plexus

maxillary v. retromandibular v. branch

superficial temporal v. posterior branch

posterior external subclavian v.

auricular v. jugular v. or venous

occipital v. angle

2) Subclavian vein

It begins at the out border of the first rib and ends behind the sternoclavicular joint.

External jugular v. is the major tributary of subclavian v. and passes downwards and backwards on the surface of the sternocleidomastiod m. to end in the subclavian v.

3) The vein of the upper limb

They are divided into two sets, superficial and deep, and rich in valves.

① The superficial veins

Dorsal digital v. dorsal metacarpal v. dorsal venous network:

The radial part of dorsal venous networkcephalic v. the front of radial side of forearm, and elbowouter border of biceps m. goove between deltoid and pectoralis major m. pierces deep fasciaaxillary v.(or subclavian v.)

The ulnar part of dorsal venous networksbasilic v. the ulnar side of forearmmedial to biceps m. a little below midpoint of armperforates deep fasciabrachial v.(or axillary v.)

Median cubital v. lying on the cubital fossa, running obliquely between the cephalic and basilica v.

②The deep veins

With the exception of the axillary vein, they are generally arranged in pairs, flanking the corresponding arteries.

3. Azygos vein

It begins as the continuation of right ascending lumbar vein. It ascends along the right side of the thoracic vertebra to the level of T4 vertebra, where it arches forwards over the root of the right lung to end in the superior vena cava.

It receives the blood from posterior intercostals v. of the right side, esophageal v. bronchial v. hemiazygos v.

Ⅱ）Inferior Vena Cava System

The system is composed by the inferior vena cava and its tributaries, which collect the blood from the abdominal and pelvic part, as well as the lower limbs.

1. Inferior vena cava

It is formed by the junction of the two common iliac veins anterior to L5vertebra, a little to the right. It ascends on the right side of abdominal aorta, passes in the groove for inferior vena cava of liver, through the vena caval opening of the diaphragm, to reach the thoracic cavity and open into the right atrium.

2. Common iliac vein

It is formed by the union of the external and internal iliac veins in front of the sacroiliac joint, and by uniting with opposite one to form the inferior vena cava at the level of L5 vertebra.

1) Internal iliac vein

The tributaries of the internal iliac vein can be divided into two sets.

parietal tributaries

inferior rectal v.

visceral tributaries interior pudendal v.

2) External iliac vein

It is the upward continuation of the femoral vein, begins behind the inguinal ligament.

3) The veins of the lower limb

They can be subdivided into two sets, superficial and deep, like those of the upper limb. Both sets are provided with valves.

① The superficial veins

Dorsal digital v. dorsal metatarsal v. dorsal venous arch

Lateral margin of dorsal venous archsmall saphenous v. behind the lateral malleolusthe midline of the back of legbetween the two heads of gastrocnemius m. popliteal fossaperforates the deep fasciapopliteal v.

Medial margin of dorsal venous archgreat saphenous v. in front of the medial malleolushe medical side of leg and knee jointbehind the medial condyle of femurthe medial side of thighsaphenous opening(at about 3-4 cm inferolateral to the pubic tubercle) perforating deep fasciafemoral v.

The five tributaries of great saphenous v. are as following:

② The deep veins of the lower limb

They accompany the arteries and their branches, and are similarly named.

3. The tributaries of the inferior vena cava

They are also divided into parietal and visceral.
Parietal inferior phrenic v.

tributaries right

left

visceral (ovarian v.) rightinferior vena cava

4. Portal vein

It is formed by the junction of the superior mesenteric and splenic veins, behind the beck of the pancreas.

It passes upwards and to the right to enter hepatoduodenal ligament, behind the common bile duct and proper hepatic artery to reach the porta of liver, where it divides right and left branches to enter the liver. In the liver this vein ramifies like an artery and ends in capillary-like vessels termed sinusoids.

It collects the blood from abdominal part of esophagus, stomach, small intestine, large intestine9with the exception of the lower part of the anal canal), and from pancreas, gallbladder, spleen.

1) The major tributaries of the portal vein

superior mesenteric v.

portal v.

superior mesenteric v.

splenic v.

left gastric v.

2) The anastomoses between the portal venous system and the vena caval system

They may collectively offer an effective collateral circulation in case of obstruction of the portal vein.

①Esophageal venous plexus: at the junction of the esophagus and stomach.

Portal v. left gastric v. esophageal venous plexusesophageal v. azygos v. superior vena cava.

②Rectal venous plexus: at the ano-rectal junction

Portal v. splenic v. inferior mesenteric v. superior rectal v. rectal venous plexusinferior rectal and anal v. internal iliac v. common iliac v. inferior vena cava.

③Periumbilical venous network: at the umbilicus.

Portal v. paraumbilical v. periumbilibal venous networkssuperficial epigastric v. great saphenous v. femoral v. external iliac v. common iliac v. inferior vena cava.

thoracoepigastric v. lateral thoracic v. xillary v. subclavian v. brachiocephalic v. superior vena cava.

superior epigastric v. nternal thoracic v. brachiocephalic v. superior vena cava.

inferior epigastric v. external iliac v. common iliac v. inferior vena cava.

④At the posterior abdominal wall: the small tributaries of the inferior and superior mesenteric v. anastomoses with the tributaries of the vena cava, such as the lower posterior intercostals v. inferior phrenic v. lumbar v. renal v. testicular9ovarian) v.

Chapter 2 The Lymphatic System

Section 1 Introduction

Ⅰ. Composition

lymph capillaries

lymphatic vessels

lymphatic trunk

lymphatic duct

lymph node

lymphatic organs spleen

thymus

respiratory tract.

Ⅱ. Charactor

Ⅰ）Lymphatic vessel

1. Lymph capillaries

They are present in almost all tissues of the body but the brain, spinal cord, epidermis, cornea, lens, enamel, cartilages, et al.

2. Lymph vessels

They are rich in valves which give them a characteristic beaded appearance, and arranged in superficial and deep sets.

3. Lymphatic trunks

The lymph vessels unite one another to form nine lymphatic trunks, they are: right and left jugular trunks

right

4. Lymphatic ducts

The right lymphatic duct and thoracic duct are formed by nine lymphtic trunks respectively.

Ⅱ） Lymphatic organs

Lymph nodes are small, oval bodies, situated in the course of lymph vessels so that the lymph passes through them on its way to blood.

The afferent lymph vessels enter the nodes on its convex surface.

The efferent lymph vessels leave the nodes on its concave surface called the hilus.

Lymph from some organ or area of the body is drained into the local corresponding lymph nodes, which are termed termed regional lymph nodes for this organ or area.

Ⅲ）Lymphatic tissue

They are widespread in the wall of the alimentary canal and respiratory tract, and can be called subepithelial lymphatic tissue.

Section 2 The Lymphatic Ducts of the Body

Ⅰ. Thoracic Duct

Right and left lumbar trunks

-----------------------------------chyle cistern---------------

Aortic hiatus of diaphragmthoracic cavityright and anterior to

vertebral column --------------inclining to the left-----------------root of

vertebral

left subclavian trunk

neck-----------------------------------left venous angle

The thoracic duct receives lymph from the lower limbs, the abdominopelvic part(wall and viscera), left lung, left half of the heart, left half of thoracic wall, left upper limb, and left half of the head and neck.

Ⅱ. Right Lymphatic Duct

right subclavian trunk

right jugular trunk right venous angle

right bronchomediastinal trunk

The right lymphatic duct receives lymph from right upper limb, right half of the head and neck, right lung, right half of the heart, right half of thoracic wall, superior surface of right lobe of liver, and part of diaphragm.

Section 3 The Lymph Vessels and Nodes of the Body

Ⅰ. The Lymph vessels and Nodes of the Head Neck

Ⅰ） Lymph Nodes of the Head

They lie at the junction between the head and neck, and are arranged in a circle from posterior to anterior, which are occipital, mastoid, parotid, submandibular, submental lymph nodes.

Ⅱ） Lymph Nodes of the Neck

They include anterior and lateral cervical lymph nodes, the latter comprises two groups.

1. Superficial lateral cervical lymph nodes

They are placed along the external jugular vein superficial to sternocleidomastoid m. they receive lymph vessels from the neck and mastoid lymph nodes, and their efferents reach the deep lateral cervical lymph nodes.

2. Deep lateral cervical lymph nodes

They lie along the internal jugular vein from the base of the skull to the root of the neck.

upper group: retropharyngeal lymph nodes

behind the nasopharynx.

lower group: supraclavicular lymph nodes

along subclavian a. and branchial plexus.

They receive the lymph vessels from the head and neck, the tongue, larynx, cervical part of esophagus and trachea, thyroid gland, upper part of thoracic wall and breast; their efferents form the jugular trunk.

Ⅱ. The Lymph Vessels and Nodes of the Upper Limb

Ⅰ）Cubital (Supratrochlear) Lymph Nodes

Which are superficial to deep fascia above the medial epicondyle of the humerus.

Ⅱ）Axillary Lymph Nodes

They lie in the axillary fossa, and may be divided into five groups.

1. Lateral lymph nodes: arranged along the axillary vessels, and receive the superficial and deep lymph vessels of the upper limbs.

2. Pectoral lymph nodes: lie along the lateral thoracic vessels, and receive the lymph vessels from anterolateral wall of thorax and abdomen, the lateral and central part of mammary gland.

3. Subscapular lymph nodes: lie on the posterior wall of axillary cavity and follow the subscapular vessels. They receive lymph vessels from the back of neck and the dorsal aspect of trunk (or neip).

4. Central lymph nodes: embedded in the fat of central part of axilla, and receive efferents from all the preceding axillary lymph nodes.

5. Apical lymph nodes: lie along the proximal side of the axillary vein, and receive lymph vessels from central lymph nodes and the upper part of breast. Their efferents unite to form the subclavian trunk.

Ⅲ. The Lymph Vessels and Nodes of the Thorax

parasternal lymph nodes

lymph nodes of thoracic wall intercostals lymph nodes

lymph nodes of thoracic anterior mediastinal lymph nodes

viscera posterior mediastinal lymph nodes

tracheobronchial lymph nodes

bronchopulmonary lymph nodes

Ⅰ）Anterior Mediastinal Lymph Nodes

They are placed anterior to the large vessels of thoracic cavity and pericardium, and drained into the bronchomediastinal trunk.

Ⅱ）Posterior Mediastinal Lymph Nodes

They are in front of the esophagus and thoracic aorta, and drained into the thoracic duct.

Ⅲ）Bronchopulmonary and Tracheobronchial Lymph Nodes

↓ vessels of lung.

↓

tracheobronchial lymph nodes: around the bifurcation of trachea, draining

(superior and interior) the lungs, bronchi, trachea, and heart.

↓

paratracheal lymph nodes: at the side of trachea.

(right and left)

↓anterior mediastinal lymph nodes

(right and left)

Ⅳ. The Lymph Vessels and Nodes of the Abdomen

Ⅰ）The Lymph Vessels and Nodes of the Abdominal Wall

Ⅱ）The Lymph Vessels and Nodes of Abdominal Unpaired Viscera

They are dividable into celiac, superior mesenteric and inferior mesenteric lymph nodes, which lie around the origin of the corresponding artery. They receive the lymph vessels from the region which are supplied by the corresponding artery, their efferents unite to form intestinal trunk.

1. Celiac lymph nodes

They are the terminal group for the stomach, duodenum, liver, gallbladder, pancreas and spleen, and their afferents are derived from the outlying lymph nodes which are placed along branches of the celiac artery.

right and left gastric lymph nodes

right and left gastroepiploic lymph nodes

pyloric lymph nodes

hepatic lymph nodes

pancreaticosplenic lymph nodes

2. Superior mesenteric lymph nodes

They receive efferents from the following lymph nodes.

mesenteric lymph nodes

ileocolic lymph nodes

right colic lymph nodes

middle colic lymph nodes

3. Inferior mesenteric lymph nodes

They collect the lymph from the underlying lymph nodes.

left colic lymph nodes

sigmoid colic lymph nodes

superior rectal lymph nodes

Ⅴ. The Lymph Vessels and Nodes of the Pelvis

They consist of three groups: external iliac lymph nodes, internal iliac lymph nodes and sacral lymph nodes, which collect the lymph from pelvic wall, viscera of pelvic cavity, and lower limbs. Their efferents pass to the common iliac lymph nodes, which are drained into right and left lumber lymph nodes.

Ⅵ. The Lymph Vessels and Nodes of the Lower Limb

Ⅰ）Popliteal Lymph Nodes

They are imbedded in the fat of the popliteal fossa, and drained into deep inguinal lymph nodes.

Ⅱ）Superficial inguinal Lymph Nodes

They lie superficial to deep fascia, below the inguinal ligament, and along the terminal part of the great saphenous vein.

They receive the superficial lymph vessels from the lower part of anterior abdominal wall, gluteal region, perineum,, external genital organs, the lower limbs except lateral side of the foot and posterolateral part of the leg. They send their efferents chiefly to deep inguinal lymph nodes.

Ⅲ）Deep Inguinal Lymph Nodes

They lie around terminal part of the femoral vein, receive efferents from the superficial inguinal lymph nodes and the deep lymph vessels of the lower limbs. Their efferents pass to external iliac lymph nodes.

Section 4 The Spleen

Ⅰ. Position

It is situated in the left hypochondriac region, deep to the 9^th to 11^th rib and its long axis is in line of the 10^th rib. It is not palpable below the left costal margin (arch).

Ⅱ. Shape

two surface diaphragmatic---convex

visceral---concave, hilus of spleen

two borders superior---sharper, splenic notch(2-3)

inferior---blunter

two extremities anterior

posterior

Section 5 The Thymus

The thymus consists of two elongated lobes closely bounded by fibrous tissue. Its greater portion lies in the front of superior mediastinum of thoracic cavity, and lesser portion extends inferiorly into anterior mediastinum or superiorly into the neck.