EXPOSURE OF THE HEART

EXPOSURE OF THE HEART

pediagenosis    November 05, 2024    Comment   

EXPOSURE OF THE HEART

Sternocostal Aspect

ANTERIOR EXPOSURE

Within the pericardium lies the heart, a hollow, muscular, four-chambered organ suspended at its base by the great vessels. In situ the heart occupies an asymmetric position, with its apex pointing anteriorly, inferiorly, and about 60 degrees toward the left. Its four chambers are arranged in two functionally similar pairs, separated from each other by the cardiac septum (see Plate 1-5). Each pair consists of a thin-walled atrium and a thicker-walled ventricle.

Thorax

Thorax

pediagenosis    August 11, 2024    Comment   

Thorax

Before describing the anatomy of the heart, it is helpful to review other anatomic features of the thoracic cavity and organs.

LUNGS IN SITU: ANTERIOR VIEW

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.

Disseminated Intravascular Coagulation

Disseminated Intravascular Coagulation

pediagenosis    September 30, 2023   

Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is a serious, life-threatening condition of the blood clotting system that can be caused by myriad insults to the body. It has a grave prognosis unless caught and treated early in the course of disease. Skin manifestations occur early and continue to progress unless the patient recovers. The skin lesions may lead to gangrene and secondary infection, further worsening the prognosis. DIC is seen as an end-stage process, caused by the consumption of blood clotting factors, that results in uncontrolled clotting and bleeding occurring simultaneously.

MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS

MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS

pediagenosis    September 30, 2023   

MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS

Membranoproliferative glomerulonephritis (MPGN) is a pattern of glomerular disease that can occur either as an idiopathic, primary phenomenon or secondary to numerous systemic conditions. It is a rare disorder, and its incidence appears to be decreasing, particularly in the developed world.

EPIDERMAL NEVUS

EPIDERMAL NEVUS

pediagenosis    September 30, 2023    Comment   

EPIDERMAL NEVUS

Epidermal nevi are benign epidermal hamartomatous growths that most commonly occur as small plaques but can be widespread and can have associated systemic findings. Epidermal nevi have a tendency to follow the embryologic lines of Blaschko. The lines of Blaschko are well defined and follow a whorl-like pattern. The reason why these lesions follow Blashko’s lines is not fully understood, but it is probably caused by an interruption of normal epidermal migration during embryogenesis.

MECHANISMS OF MOLECULAR SIGNALING IN NEURONS

MECHANISMS OF MOLECULAR SIGNALING IN NEURONS

pediagenosis    September 30, 2023   

MECHANISMS OF MOLECULAR SIGNALING IN NEURONS

Types of molecular signaling in neurons are shown, including ionotropic receptors (both voltage-gated ion channels and ligand-gated channels) and metabotropic receptors.

Transplant Rejection

Transplant Rejection

pediagenosis    September 30, 2023    Comment   

Transplant Rejection

Immunologically mediated allograft damage or rejection may be hyperacute, acute or chronic. Acute rejection is classified as acute cellular/T cell-mediated rejection or acute antibody-mediated/ humoral rejection, according to which arm of the immune system is principally involved in mediating allograft damage.

Airway Management And Sedation

Airway Management And Sedation

pediagenosis    September 30, 2023    Comment   

Airway Management And Sedation

Airway management in the Emergency Department is more challenging than in the operating room as patients presenting to the Emergency Department must be assumed to be non-fasted, may be physiologically unstable, and may have head, neck or facial injuries.

INTERSEX FEMALE PSEUDOHERMAPHRODITISM

INTERSEX FEMALE PSEUDOHERMAPHRODITISM

pediagenosis    September 30, 2023   

INTERSEX: FEMALE PSEUDOHERMAPHRODITISM

A female pseudohermaphrodite is an individual with ovaries but whose external genitalia have a male appearance. This disorder of sexual development usually results from hormonal disturbances. The maternal use of androgens or high doses of certain weakly androgenic synthetic progestogens (progestins) can masculinize or virilize the fetal female external genitalia during susceptible times in pregnancy. An example of a weakly androgenic substance is the sex steroid danazol, a derivative of ethisterone (17α-ethinyl-testosterone) that is used to treat severe endometriosis. Progestogens currently used for luteal support of pregnancy in in vitro fertilization (IVF) protocols or for prevention of preterm birth are progesterone, 17α-hydroxyprogesterone caproate, and dydrogesterone. Along with clitoral enlargement (clitoromegaly), some degree of fusion of the urogenital folds can occur with exposure from the 8th through the 12th week of gestation. This can present as ambiguous genitalia at birth. If exposure occurs after the 12th gestational week, then only clitoral enlargement occurs. Females with clitoral enlargement mature normally and have normal fertility, as there is almost total regression of the genital anomaly. Surgical correction of labioscrotal fusion is also a relatively simple procedure if needed. A much rarer cause of clitoromegaly is Fraser syndrome, characterized by defects including underdevelopment of the eyes (cryptophthalmos) and linked to the gene FRAS1, which may be involved in skin epithelial morphogenesis.

BOWENOID PAPULOSIS

BOWENOID PAPULOSIS

pediagenosis    September 30, 2023    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.