The main structure of the renal medulla

Renal medulla is a relatively important substance in the human body, mainly located in the kidneys. It has a great impact on the normal function of the kidneys and the health of the human body. After all, the kidneys are important organs in the human body. If there is a problem with the kidneys, the person's physical and mental health will be affected to a certain extent. Below, we will introduce in detail the main structure of the renal medulla and other related knowledge.

1. Introduction

The renal medulla is composed of 15-20 renal pyramids. The base of the cone faces the cortex, and the tip of the cone is blunt and extends to the renal sinus, called the renal papilla. Sometimes 2-3 renal pyramids combine to form a renal papilla, which has many papillary holes at the top, through which the urine formed by the kidney flows into the renal calyx. The part of the renal cortex extending into the medulla between the renal pyramids is called renal columns.

There are about 7-8 funnel-shaped calyces in the renal sinus. The renal calyces surround the renal papilla to receive the urine discharged from the renal papilla. 2-3 calyces combine to form a major renal calyx, and there are about 2-3 major renal calyces in total, which then combine to form a funnel-shaped renal pelvis that is flat front to back. After the renal pelvis leaves the kidney hilum, it bends downward, gradually becomes thinner, and transforms into the ureter.

2. Main Structure

The renal parenchyma is composed of many urinary tubules, which can be divided into the urinary part and the urinary part. The urinary part is also called the nephron. A nephron consists of two parts: the renal corpuscle and the renal tubule.

The renal corpuscle is composed of a special group of arterial capillaries - the glomerulus and the glomerular capsule wrapped around it. The glomerular capsule is actually an enlarged and sunken blind end at the beginning of the urinary system. The renal tubule originates from the glomerular capsule, and after leaving the renal body, it first coils into the proximal convoluted tubule, then descends and bends back to form the loop of Medullary, and finally coils into the distal convoluted tubule and is injected into the urinary part.

The urinary part first consists of a straight collecting duct, which collects distal convoluted tubules along the way and gradually merges into the papillary duct, opening into the renal papilla. When blood passes through the glomerulus, all components in the plasma except protein can be filtered into the glomerular capsule. When the filtrate passes through the renal tubules, some useful substances and some water are reabsorbed and returned to the blood, and the rest is excreted through the urinary part as urine.

The renal corpuscles and the proximal and distal convoluted tubules constitute the cortex; the medullary mixing and urinary part mainly form the medulla, and some tubules extend into the cortex to form the renal medullary radiata.

3. Renal medullary necrosis

Renal medullary necrosis is also known as renal papillary necrosis and necrotizing papillitis. Its essence is ischemic necrosis of the renal papilla and the adjacent renal medulla. This disease can occur in a variety of diseases, mainly diseases that cause chronic tubulointerstitial nephropathy. In these chronic tubulointerstitial nephropathy, the lesions in the medullary zone of the kidney are often more serious. The basic lesion is impaired renal blood circulation, causing localized or diffuse ischemic necrosis of the distal end of one or more renal pyramids.