Innervation of Genitalia and Perineum: Nerves, Scrotal Pain & Bulbospongiosus Reflex

Innervation of Genitalia and Perineum: Nerves, Scrotal Pain & Bulbospongiosus Reflex

pediagenosis    August 17, 2026   

Innervation of Genitalia II and of Perineum

The nerves supplying the anterior scrotal wall are the ilioinguinal and the external spermatic branch of the genitofemoral branch of the lumbar nerves. The superficial perineal branches of the internal pudendal nerve, along with branches from the posterior cutaneous nerves of the thigh, innervate the posterior scrotal wall. The unstriated muscle in the dartos fascia is innervated by fine autonomic fibers that arise from the hypogastric plexus and reach the scrotum along with the blood vessels. Because of this complex innervation from various sources, the entire scrotum is difficult to anesthetize with local anesthesia, unlike the spermatic cord and testicles.

Connective Tissue: Types, Functions, Cells, and Extracellular Matrix

Connective Tissue: Types, Functions, Cells, and Extracellular Matrix

pediagenosis    August 16, 2026   

Connective or Supportive Tissue.

Connective or supportive tissue is the most abundant tissue in the body. As its name suggests, it connects and binds or supports the various tissues. Connective tissue is unique in that its cells produce the extracellular matrix that supports and holds tissues together. The capsules that surround organs of the body are composed of connective tissue. Bone, adipose tissue, and cartilage are specialized types of connective tissue that function to support the soft tissues of the body and store fat. The proximity of the extracellular matrix to blood vessels allows it to function as an exchange medium through which nutrients and metabolic wastes pass.

Sporotrichosis: Causes, Symptoms, Diagnosis, Histology and Treatment

Sporotrichosis: Causes, Symptoms, Diagnosis, Histology and Treatment

pediagenosis    August 16, 2026    Comment   

Plate 6-24

SPOROTRICHOSIS

Sporothrix schenckii is an environmental fungus that is capable of causing human disease after direct inoculation into the skin. Inoculation is the cause of cutaneous sporotrichosis, which is considered to be a subcutaneous mycosis. Unusual cases of inhalation sporotrichosis have been described in the literature, as have cases of central nervous system disease. These cases occur almost exclusively in immunosuppressed hosts. Sporotrichosis has classically been associated with inoculation after the prick from a rose plant. This is well reported; the fungus can be isolated from rose plants but is also found on many other plants and in soil environments. 

Vocal Cord Dysfunction (VCD): Symptoms, Diagnosis, Causes and Treatment

Vocal Cord Dysfunction (VCD): Symptoms, Diagnosis, Causes and Treatment

pediagenosis    August 14, 2026   

VOCAL CORD DYSFUNCTION

Vocal cord dysfunction (VCD), also known as paradoxical vocal cord motion (PVCM), is a relatively poorly understood laryngeal disorder manifest by inappropriate adduction, or closing, of the vocal cords during inspiration. This is in contrast to the normal respiratory cycle, in which the vocal cords are abducted, or open, during inspiration and only begin to adduct toward the end of exhalation or with the onset of phonation. Physiologically, partial adduction of the vocal cords at the end of the expiratory phase maintains alveolar patency by generating positive end-expiratory pressure. Full adduction of the vocal cords occurs normally during phonation. As air expelled from the lungs encounters a closed glottis, subglottic air pressure increases, which in turn provides the force necessary to vibrate the vocal cords and produce voice. In contrast, paradoxical adduction of the vocal cords during inspiration in patients with VCD results in acute, intermittent episodes of functional airway obstruction.

Uterus and Adnexa Anatomy: Uterus, Cervix, Fallopian Tubes and Ovaries

Uterus and Adnexa Anatomy: Uterus, Cervix, Fallopian Tubes and Ovaries

pediagenosis    August 14, 2026    Comment   

UTERUS AND ADNEXA

The uterus is a pear-shaped, thick-walled, hollow, muscular organ situated between the bladder and rectum. The fundus is the dome-shaped portion above the level of entrance of the fallopian tubes. The body, or corpus, lies below this and is separated from the cervix by a slight constriction, termed the isthmus. The cavity of the uterine body is a flattened potential space, triangular in shape. The uterine tubes open into its basal angles. Its apex is continuous with the cervical canal at the internal os. The uterine wall is composed of an outer serosal layer (peritoneum); a firm, thick, intermediate coat of smooth muscle (myometrium); and an inner mucosal lining (endometrium).

Phenylketonuria (PKU): Symptoms, Causes, Diagnosis, Treatment & Low-Phenylalanine Diet Guide

Phenylketonuria (PKU): Symptoms, Causes, Diagnosis, Treatment & Low-Phenylalanine Diet Guide

pediagenosis    August 07, 2026   

 

NORMAL AND ABNORMAL METABOLISM OF PHENYLALANINE

         PHENYLKETONURIA

Phenylalanine is an essential amino acid that serves as a substrate for many different biochemical pathways. Two end products that use phenylalanine as their precursors are melanin and epinephrine. Under normal physiological and biochemical environments, any excess amount of phenylalanine is converted into tyrosine by the liver and used for a host of biochemical processes including protein synthesis. In patients with phenylketonuria, the enzyme in the liver that converts phenylalanine into tyrosine is completely absent. This inborn error of metabolism is one of the most thoroughly researched disease states. With early detection and therapy, the severe sequelae of phenylketonuria can be avoided. Screening is performed soon after birth for all children in the United States and in most of the world. Children born in regions with poor medical infrastructure and no testing are at risk for the disease. Once the disease symptoms have appeared, therapy usually cannot reverse the damage that has been done. Phenyl-ketonuria is inherited in an autosomal recessive manner, but many genotypes have been described, and many mutations in the responsible gene have been reported. The defect is located on the long arm of chromosome 12, where the PAH gene encodes the protein, phenylalanine hydroxylase.

Bentall Procedure: Indications, Surgical Steps, Risks, Recovery, and Long-Term Outcomes

Bentall Procedure: Indications, Surgical Steps, Risks, Recovery, and Long-Term Outcomes

pediagenosis    August 07, 2026   

Bentall Procedure

Keywords: Bentall Procedure, Operations for Valvular Heart Disease, bentall, aortic replacement, valve replacement, composite aortic valve, aortic replacement.

Abstract

The Bentall procedure technique has evolved to become a standardized, reliable procedure that can be performed for a variety of aortic vavle and aortic root pathology. The technique described in this chapter describes the details of the author’s technique and variations for specific pathology. Myocardial protection and cerebral protection is discussed.

Male Pseudohermaphroditism (46,XY DSD): Causes, Symptoms, Diagnosis, Treatment & Gonadal Disorders

Male Pseudohermaphroditism (46,XY DSD): Causes, Symptoms, Diagnosis, Treatment & Gonadal Disorders

pediagenosis    August 07, 2026   

INTERSEX: MALE PSEUDOHERMAPHRODITISM I GONADAL

The pseudohermaphrodite is an individual with the gonads of only one sex but with genitalia (internal and external) and secondary sex characters exhibiting sexual ambiguity. Such a simple classification of intersex is based purely on phenotype or morphology, without regard to genetic etiology. Factors that contribute to such disordered development include (1) gene mutations, (2) abnormal maternal hormonal influences, and (3) abnormal hormonal influences from the embryonic gonad, adrenal, or other endocrine organ. The type and degree of disordered development depend on the intensity and timing of these influences during embryonic life.

Scrotal Wall Anatomy: Layers, Structure, Functions, Embryology & Clinical Significance

Scrotal Wall Anatomy: Layers, Structure, Functions, Embryology & Clinical Significance

pediagenosis    August 07, 2026   

SCROTAL WALL

The testicles are maintained in position within the scrotal cavity by the structures of the spermatic cord. Each testicle and spermatic cord is invested in six distinct tissue layers that are acquired as a result of the descent of the gonads from the retroperitoneum into the scrotum during fetal life.

Tracheal Resection and Anastomosis: Surgical Procedure, Indications, Techniques, Risks, and Recovery

Tracheal Resection and Anastomosis: Surgical Procedure, Indications, Techniques, Risks, and Recovery

pediagenosis    August 02, 2026    Comment   

TRACHEAL RESECTION AND ANASTOMOSIS

Tracheal stenosis can be idiopathic but is most commonly the result of prior intubation or tracheostomy. Common areas of stenosis were previously located in the mid-trachea related to high-pressure, low-volume endotracheal tube cuffs; however, contemporary endotracheal appliances have low-pressure cuffs. Today stenotic lesions are typically found in the proximal or subglottic trachea at the site of a prior stoma. Mid- to distal tracheal resections are more likely performed as therapy for benign or malignant airway tumors. In most cases of symptom-producing stenosis of the trachea, conservative therapy, consisting of repeated dilatations, is either contraindicated or has proven to be ineffective. Consequently, surgical correction is necessary. The procedure of choice is resection of the stenotic tracheal segment with primary reconstruction via an end-to-end anastomosis (see illustration).