Deltoid

Origin: Lateral anterior 1/3 of the clavicle, coracoid process of the acromion, scapula spine

Insertion: the deltoid tuberosity on the lateral surface of the humerus

Actions: The main action of the deltoid is to abduct the humerus (an action initiated with supraspinatus). The clavicular portion adducts the humerus towards the midline and medially rotates the humerus to aid flexion of the humerus by pectoralis major. The spinous portion aids extension of the humerus by latissimus dorsi by laterally rotating the humerus.

Nerve supply: the axillary nerve C5, C6

Pronunciation: dehl-toyed

Serratus Anterior Muscle

Origin: Anterior surfaces of ribs 1-8 and the anterior intercostal membranes down the midclavicular line

Insertion: The medial, anterior border of the scapula

Actions: Protracts the scapula and laterally rotates the scapula

Nerve supply: Long thoracic nerve C5, C6, C7.

C5 supplies the slips attaching to ribs 1 and 2

C6 supplies the slips attaching to ribs 3 and 4

C7 supplies the slips attaching to ribs 5 to 8

Pronunciation: seh-rate-us an-tea-ree-uhr

Subscapularis Muscle

Origin: The medial 2/3 of the subscapular fossa of the anterior surface of the scapula and the lower 2/3 of the lateral border of the scapula

Insertion: The lesser tubercle of the humerus and the anterior shoulder capsule

Actions: Adducts the arm, medially rotates the humerus. It also stabilises the shoulder joint by preventing anterior dislacement of the humerus – this is part of its role as one of the rotator cuff muscles.

Nerve supply: The upper and lower subscapular nerves C5, C6

Pronunciation: suhb-skap-you-lah-rihs

Long Head of Triceps Brachii Muscle

Origin: The infraglenoid tubercle of the scapula

Insertion: The posterior portion of the proximal olecranon process of the ulna

Action: Extends the forearm at the elbow and extends the arm at the shoulder joint

Nerve supply: The radial nerve C7, C8

Pronunciation: try-seps brak-ee-eye

Short Head of Biceps Brachii Muscle

Origin: The apex of the coracoid process of the scapula, with coracobrachialis

Insertion: The radial tuberosity of the radius, forming an aponeurosis which blends with the deep fascia of the forearm

Actions: Supinates a partially flexed forearm and flexes a supinated forearm

Nerve supply: The musculocutaneous nerve C5,C6

 

Pronunciation: by-seps brak-ee-eye

Coracobrachialis Muscle

Origin: From the apex of the coracoid process, with the short head of biceps brachii

Insertion: The middle of the medial surface and medial border of the humerus

Action: It adducts the humerus at the shoulder joint and flexes the humerus at the shoulder joint

Nerve supply: The musculocutaneous nerve C6, C7

Pronunciation: kor-racko-brack-ee-ah-liss

The Abdominal Oesophagus

Emerges through the right crus of the diaphragm at T10, passing from the oesophageal hiatus to the cardial orifice of the stomach.

It is accompanied by the anterior vagal trunk, consisting of several smaller fibres, and the posterior vagal trunk, consisting of a single fibre.

It is a muscular tube that uses peristalsis to propel food into the gastrointestinal system.

The Stomach

The stomach is the most dilated part of the gastrointestinal tract. A J-shaped organ it is positioned between the abdominal oesophagus and the duodenum.

It is divided into four regions:

• the cardia – surrounding the gastroesophageal junction
• the fundus
• the body
• the pyloric part – the most distal end, containing pylorus – the sphincter between the stomach and the duodenum

The stomach covered anteriorly by the left lobe of the liver and the diaphragm.

It is given blood supply by branches of the celiac trunk (from the abdominal aorta):

• splenic artery
• left gastric artery
• common hepatic artery

Venous drainage is through the:

• short gastric veins
• left and right gastroepiploic veins
• left and right gastric veins

All of which eventually drain to the portal vein and the liver.

Lymphatic drainage is to the preaortic nodes

Sympathetic nerve supply is by the thoracic splanchnic nerves

Parasympathetic nerve supply is by the vagus nerve

The Kidneys

The kidneys are retroperitoneal – i.e. they lie outside the peritoneal cavity.

They are positioned at approximately the level of T12 to L3. The right kidney is lower than the left due to the placement of the liver.

Both kidneys are surrounded by two layers of fat – the pararenal and perirenal layers. These protect the kidneys by absorbing shocks and locomotive forces.

The right kidney is in relation to:

• superiorly – the right suprarenal gland
• laterally – the liver and colic flexure
• medially – the duodenum
• inferiorly – the small intestines

The left kidney is in relation to:

• superiorly – the left suprarenal gland and the stomach
• laterally – the spleen, colic flexure and descending colon
• inferiorly – the jejunum

The kidneys are supplied by the left and right renal artery, branches of the abdominal aorta. The left and right renal veins provide venous drainage to the inferior vena cava and then the heart.

The Spleen

The spleen is the largest lymphatic organ in the body.

It is located under the costal margin, approximately at the level of the 10th rib.

It is concealed anteriorly by the greater curvature of the stomach and the left colic flexure.

It has diaphragmatic and visceral surfaces.

The diaphragmatic surface is separated from the 10th, 11th and 12th ribs by the diaphragm.

The visceral surface is in relation to the stomach, left kidney and left colic flexure.

Ligaments attached to the spleen are all double folds of peritoneum.

Inferiorly, the phrenicocolic ligament joins the spleen to the colon.

The gastrosplenic and splenorenal ligaments join the spleen to the stomach and the left kidney, respectively.

The hilum of the spleen contains the splenic artery and vein.