Thorax Anatomy: Thoracic Cage, Lungs, Mediastinum, Heart & Major Structures

Thorax Anatomy: Thoracic Cage, Lungs, Mediastinum, Heart & Major Structures

pediagenosis    October 02, 2026    Comment   

LUNGS IN SITU: ANTERIOR VIEW

        Thorax

Before describing the anatomy of the heart, it is helpful to review other anatomic features of the thoracic cavity and organs. The thorax proper constitutes the upper part of the body or trunk, with a shape between a barrel and a truncated cone that is functionally favorable. Although the intrathoracic pressure is often subatmospheric, the chest wall is still able to retain its integrity by means of rather thin, lightweight skeletal elements. The thoracic cavity occupies only the upper part of the thoracic cage. The abdominal (peritoneal) cavity reaches upward as high as the lower tip of the sternum, affording protection to large, easily injured abdominal organs such as the liver, spleen, stomach, and kidneys.

Granuloma Inguinale (Donovanosis): Symptoms, Diagnosis & Treatment

Granuloma Inguinale (Donovanosis): Symptoms, Diagnosis & Treatment

pediagenosis    October 01, 2026   

GRANULOMA INGUINALE

Granuloma inguinale (also known as “Donovanosis”) is a sexually transmitted bacterial infection of endemic proportions in many underdeveloped countries. The pathognomic feature of the disease are Donovan bodies on Giemsa or Wright stain, intracellular inclusions representing the causative gram negative Klebsiella granulomatis bacteria that have been engulfed by mononuclear phagocytes. Clinically, granuloma inguinale is characterized by painless genital ulcers that appear 10 to 40 days after contact and that can be mistaken for syphilis. However, unlike syphilis, they can progress to mutilate and destroy tissue and are often superinfected with other pathogenic organisms. The lesions occur in the region of contact, which is typically the penile shaft or perineum, and contain Donovan bodies when the superficial layers of the ulcer are scraped or when stained granulation tissue is examined.

Thoracolumbar and Sacral Spine Anatomy: Vertebrae, Discs & Ligaments

Thoracolumbar and Sacral Spine Anatomy: Vertebrae, Discs & Ligaments

pediagenosis    September 30, 2026    Comment   

THORACIC VERTEBRAE AND LIGAMENTS

ANATOMY OF THE THORACOLUMBAR AND SACRAL SPINE

THORACIC VERTEBRAE AND LIGAMENTS

The 12 thoracic vertebrae (T1 to T12) are intermediate in size between the smaller cervical and the larger lumbar vertebrae. The heart-shaped vertebral bodies are slightly taller posteriorly than anteriorly, producing a slight wedge shape (see Plate 1-17). Vertebrae are easily recognized by their costal facets on both sides of the bodies and on all the transverse processes except those of T11 and T12. The costal facets articulate with the facets on the heads and tubercles of the corresponding ribs. The spinal canal is smaller and more rounded than in the cervical spine and corresponds to the more circular shape of the spinal cord in the thoracic region. The spinal canal is formed by the posterior surfaces of the vertebral bodies and by the pedicles and laminae forming the vertebral arches. The stout pedicles are directed posteriorly; they have shallow superior and much deeper inferior vertebral notches. The laminae are short and relatively thick and partially overlap each other from above downward.

Flexor and Extensor Tendons of the Hand: Anatomy, Function and Mechanism

Flexor and Extensor Tendons of the Hand: Anatomy, Function and Mechanism

pediagenosis    September 30, 2026   

FLEXOR AND EXTENSOR TENDONS OF THE HAND

As the flexor and extensor tendons pass from the wrist to the hand, clinical zones have been described that help physicians articulate more precisely the significant anatomic differences that exist in each zone that affect finger function after injury (see Plates 4-5 and 4-6). As the extensor digitorum tendons diverge over the dorsum of the hand, they are interconnected by inter-tendinous connections. These prominently interconnect the tendons for the third, fourth, and fifth digits and severely limit the independent action of these digits, especially the fourth digit. Independent extensor action is retained for the index finger. The convergence of the tendon of the extensor pollicis longus muscle toward the tendons of the abductor pollicis longus and extensor pollicis brevis muscles defines a hollow known as the anatomic snuffbox (see Plate 4-14). In the floor of this hollow, the radial artery passes toward the dorsum of the hand and gives off its dorsal carpal branch.

Duodenal Fossae and Ligament of Treitz: Anatomy, Location and Clinical Significance

Duodenal Fossae and Ligament of Treitz: Anatomy, Location and Clinical Significance

pediagenosis    September 29, 2026    Comment   

DUODENAL FOSSAE AND LIGAMENT OF TREITZ

The duodenojejunal flexure lies left of the midline at the level of the first and second lumbar vertebrae. The suspensory muscle of the duodenum (ligament of Treitz, suspensory ligament of the duodenum) is a flat, fibromuscular ligament arising from the right crus of the diaphragm near the aortic hiatus. It passes, with individual variations, inferior to the left of the celiac trunk and superior mesenteric artery, posterior to the pancreas, to reach the duodenojejunal flexure. The smooth muscle cells of the ligament are largely continuous with the musculature of the celiac and superior mesenteric arteries; at the intestinal attachment they are connected with the longitudinal muscular layer of the gut, some extending as far as the mesentery of the small intestine. The attachment of the ligament to the duodenum may be quite narrow or it may extend over a considerable portion of the third part of the duodenum. If the suspensory ligament of the duodenum is short, the duodenojejunal flexure is high; if it is long, the flexure may lie so low that the terminal duodenal segment does not take the usual ascending course.

Tongue and Salivary Glands: Sections Anatomy

Tongue and Salivary Glands: Sections Anatomy

pediagenosis    September 29, 2026   

Tongue and Salivary Glands: Sections Anatomy

Orbicularis oris muscle, Buccinator muscle, Buccopharyngeal fascia, Facial artery and vein, Pterygomandibular raphe, Lingual nerve and superior pharyngeal constrictor muscle, Buccal nerve and branches, Masseter muscle, Palatoglossus muscle in palatoglossal arch, Palatine tonsil, Palatopharyngeus muscle in palatopharyngeal arch, Ramus of mandible, Inferior alveolar artery, vein, and nerve to mylohyoid muscle, Medial pterygoid muscle, Styloglossus muscle.

Radioulnar Joints Anatomy: Proximal, Distal, Pronation & Supination

Radioulnar Joints Anatomy: Proximal, Distal, Pronation & Supination

pediagenosis    September 28, 2026   

Radioulnar Joints Anatomy

The radius and ulna articulate at the proximal and distal radioulnar joints, which are synovial. At the proximal joint, the head of the radius articulates with the radial notch of the ulna (Fig. 3.88). The head and neck are encircled by the anular ligament, which attaches to the anterior and posterior margins of the notch on the ulna (Fig. 3.92) and blends with the capsule and radial collateral ligament of the elbow. Thus the cavity of the proximal joint is continuous with that of the elbow.

Skin Keratinization: Process, Stages, and Functions of the Stratum Corneum

Skin Keratinization: Process, Stages, and Functions of the Stratum Corneum

pediagenosis    September 28, 2026    Comment   

Skin Physiology : The Process Of Keratinization

Keratinization, also known as cornification, is unique to the epithelium of the skin. Keratinization of the human skin is of paramount importance; it allows humans to live on dry land. The process of keratinization begins in the basal layer of the epidermis and continues upward until full keratinization has occurred in the stratum corneum. The function and purpose of keratinization is to form the stratum corneum.

Stomach Anatomy: Parts, Relations, Normal Variations, and Functions

Stomach Anatomy: Parts, Relations, Normal Variations, and Functions

pediagenosis    September 27, 2026    Comment   

Anatomy, Normal Variations, and Relations of Stomach

The stomach is an enlarged reservoir of the proximal digestive tract, in which ingested food is soaked in gastric juice containing enzymes and hydrochloric acid and then released spasmodically into the duodenum by gastric peristalsis. The form and size of the stomach vary considerably, depending on the position of the body and the degree of filling.

Esophagus in Situ Anatomy

Esophagus in Situ Anatomy

pediagenosis    September 27, 2026    Comment   

Esophagus in Situ Anatomy

Common carotid artery, Anterior scalene muscle, Phrenic nerve, Posterior scalene muscle, Brachial plexus, Subclavian artery, Thyrocervical trunk, Vagus nerve (CN X) 1st rib (cut), Brachiocephalic trunk, Trachea, Arch of aorta, Arch of azygos vein, Right main bronchus, Thoracic part of esophagus, Esophageal plexus, Mediastinal part of parietal pleura (cut edge), Anterior vagal trunk (CN X), Inferior vena cava (cut), Hepatic veins (cut),