Medial Surface of the Lungs: Anatomy, Hilum and Impressions

Medial Surface of the Lungs: Anatomy, Hilum and Impressions

pediagenosis    October 09, 2026    Comment   

Medial Surface Of The Lungs

The medial (mediastinal) surfaces of the right and left lungs present concave mirror images of the right and left sides of the mediastinum so that in addition to the structures forming the root of the lung, the medial lung surface presents distinct impressions made by the structures constituting the mediastinum (see Plates 1-18 and 1-19).

Congenital Uterine Anomalies: Types, Causes and Anatomy

Congenital Uterine Anomalies: Types, Causes and Anatomy

pediagenosis    October 09, 2026    Comment   

CONGENITAL ANOMALIES

The female genital tract develops from paired embryologic structures, the müllerian ducts, which give rise to the tubes and uterus as well as the upper two-thirds of the vagina. The upper or cephalic portion of the müllerian ducts, shortly after having made its appearance during the second month of fetal life, develops and courses longitudinally, parallel and lateral to the wolffian (mesonephric) ducts. In the caudal region of the mesonephros, the müllerian ducts approach the midline, taking an oblique route for a short distance while crossing the wolffian ducts, then turn again, assuming a longitudinal direction now medial to the wolffian ducts. In this proximal part, the right and the left müllerian ducts approach each other and finally fuse to form the uterovaginal canal. The cephalic, originally longitudinal, part of the ducts are transformed and differentiate into the fallopian tubes. The short part, in the region where the wolffian duct is crossed in the early stages, gives rise to the uterine fundus and the uterine–tubal junction, whereas the uterine cervix and the vagina take their origin from the lower longitudinal portion of the müllerian ducts. The uterine corpus develops from a very small part of the müllerian ducts, a fact that explains the ratio of cervical length to the length of the entire uterus during fetal life and long after, until the ovarian hormones display their effect on the responsive tissue of the uterine body.

Pharynx

Pharynx

pediagenosis    October 07, 2026   

Pharynx

The pharynx is a musculomembranous tube; much of its anterior wall is absent due to the fact that the right and left nasal cavities, oral cavity, and larynx open into its anterior side. It extends from the base of the skull to the inferior border of the cricoid cartilage at the level of the lower margin of the sixth cervical vertebra, at which time it becomes continuous with the esophagus. In addition to the cavities already listed, the pharynx also communicates with the middle ear on each side by means of the auditory (eustachian) tube; this fact explains how infections spread from the pharynx to the middle ear, making a total of seven cavities with which it has communication. The transverse diameter of the pharynx exceeds the anteroposterior diameter, which is greatest superiorly and is diminished to nothing inferiorly where the anterior and posterior walls are in contact unless separated during the act of swallowing. The transverse diameter does not differ greatly throughout the length of the pharynx, except where it narrows at the lower end.

Bowenoid Papulosis: Symptoms, Causes, Diagnosis and Treatment

Bowenoid Papulosis: Symptoms, Causes, Diagnosis and Treatment

pediagenosis    October 06, 2026    Comment   

BOWENOID PAPULOSIS

Bowenoid papulosis is considered to be a special variant of squamous cell carcinoma (SCC) in situ that is caused by the human papillomavirus (HPV) and is located predominantly in the genital region, particularly on the penile shaft. As with other HPV-induced genital skin cancers, HPV 16, 18, 31, and 33 are the more common viral types, although many other subtypes have been found in these lesions. Bowenoid papulosis is considered by some to be a precancerous lesion with a low risk of developing invasive properties and by others as a true SCC in situ. This lesion does have a low risk of invasive transformation; if it is treated, the prognosis is excellent. It is believed that approximately 1% of all bowenoid papulosis lesions will develop into invasive SCC.

Cross Section at T12–L1, Intervertebral Disc Anatomy

Cross Section at T12–L1, Intervertebral Disc Anatomy

pediagenosis    October 06, 2026    Comment   

Cross Section at T12–L1, Intervertebral Disc Anatomy

Transverse colon, Ascending colon (right colic flexure) (Common) bile duct, Descending (2nd) part of duodenum, Inferior vena cava, Right suprarenal gland, Superior pole of right kidney, Right crus of respiratory diaphragm, T12–L1 intervertebral disc,

Stomach in Situ Anatomy

Stomach in Situ Anatomy

pediagenosis    October 06, 2026    Comment   

Stomach in Situ Anatomy

Falciform ligament, Gallbladder, Pylorus, Caudate lobe of liver, Duodenum, Left lobe of liver, Head of pancreas, Hepatic portal vein, Inferior vena cava, Liver, left lobe, Body of pancreas, Superior mesenteric artery, Abdominal aorta, Hepatoduodenal ligament, Hepatogastric ligament, Lesser omentum, Abdominal part of esophagus, Cardiac notch (incisure), Fundus of stomach, Respiratory diaphragm.

Pulmonary Agenesis, Aplasia, and Hypoplasia: Causes, Diagnosis, and Treatment

Pulmonary Agenesis, Aplasia, and Hypoplasia: Causes, Diagnosis, and Treatment

pediagenosis    October 05, 2026   

Pulmonary Agenesis, Aplasia, and Hypoplasia

Three different degrees of arrested development of the lungs may occur: (1) agenesis, in which there is a complete absence of one lung or both lungs and no trace of bronchial or vascular supply or parenchymal tissue; (2) aplasia, in which there is a suppression of all but a rudimentary bronchus ending in a blind pouch and there are no pulmonary vessels and no parenchyma; and (3) hypoplasia, in which there is incomplete development of the lung, which is smaller in weight and volume, and there is a reduced number of airways branches, alveoli, arteries, and veins.

Nephrotic Syndrome: Causes, Symptoms, Diagnosis, Pathophysiology and Treatment

Nephrotic Syndrome: Causes, Symptoms, Diagnosis, Pathophysiology and Treatment

pediagenosis    October 04, 2026   

Overview Of Nephrotic Syndrome

The nephrotic syndrome encompasses a constellation of clinical and laboratory findings related to the loss of large quantities of protein in urine. The major symptom is edema, and the laboratory findings include (1) “nephrotic-range” proteinuria, defined in adults as more than 3.5 g of protein excretion per 24 hours, (2) hypoalbuminemia, and (3) hyperlipidemia. The thresh old for nephrotic proteinuria in children is lower and depends on body weight.

Skin Embryology: Development of the Epidermis, Dermis, Hair and Nails

Skin Embryology: Development of the Epidermis, Dermis, Hair and Nails

pediagenosis    October 03, 2026    Comment   

Embryology Of The Skin.

The human skin develops from two special embryonic tissues, the ectoderm and the mesoderm. Epidermal tissue is derived from the embryonic ectoderm. The dermis and subcutaneous tissue are derived from the embryonic mesoderm. The developmental interactions between mesoderm and ectoderm ultimately determine the nature of human skin. Interestingly, neural tissue and epidermal tissue are both derived from the ectoderm. It is believed that calcium signaling is critical in determining the fate of the ectoderm and its differentiation into either epidermis or neural tissue.

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.