
The Urinary System College of Life Sciences Yuting Cui
The Urinary System College of Life Sciences Yuting Cui

Introduction Components of The Urinary System:Two kidneys,two ureters, one urinary bladder and a single urethra make up the urinary system. The kidneys,as the main excretory organs,are critically important in maintaining the balance of substances required for internal constancy.The kidneys eliminate from the body a variety of metabolic products,such as urea,uric acid,and creatinine. Further the kidneys conserve or excrete water and electrolytes as required so that the internal balance of these substances will be maintained.In fact,kidney malfunction can cause severe and even fatal problems as a result of upsets in fluid and electrolyte balance
Introduction Components of The Urinary System: Two kidneys, two ureters, one urinary bladder and a single urethra make up the urinary system. The kidneys, as the main excretory organs, are critically important in maintaining the balance of substances required for internal constancy. The kidneys eliminate from the body a variety of metabolic products, such as urea, uric acid, and creatinine. Further the kidneys conserve or excrete water and electrolytes as required so that the internal balance of these substances will be maintained. In fact, kidney malfunction can cause severe and even fatal problems as a result of upsets in fluid and electrolyte balance


The Kidneys The kidneys are a pair of bean-shaped,reddish-brown organs. Each kidney has two extremities,two surfaces,and two borders. On medial border of the kidney there is a vertical slit,the renal hilum,which transmits the renal vessels,nerves and a part of pelvis.The renal hilum leads into a central recess named the renal sinus,which is filled with the branches of the renal artery and vein,nerves,lymphatic vessels,minor renal calices,major renal calices,renal pelvis and adipose tissue
The Kidneys The kidneys are a pair of bean-shaped, reddish-brown organs. Each kidney has two extremities, two surfaces, and two borders. On medial border of the kidney there is a vertical slit, the renal hilum, which transmits the renal vessels, nerves and a part of pelvis. The renal hilum leads into a central recess named the renal sinus, which is filled with the branches of the renal artery and vein, nerves, lymphatic vessels, minor renal calices, major renal calices, renal pelvis and adipose tissue

The Kidneys The structures which pass through the renal hilum are enclosed together by the connective tissue,to form the renal pedicle.From the front backward,the order of these structures in the renal pedicle is renal vein,renal artery,renal pelvis,and from superior to inferior is the renal artery,renal vein and renal pelvis
The Kidneys The structures which pass through the renal hilum are enclosed together by the connective tissue, to form the renal pedicle. From the front backward, the order of these structures in the renal pedicle is renal vein, renal artery, renal pelvis, and from superior to inferior is the renal artery, renal vein and renal pelvis


The Structure of Kidney On the coronal section of a kidney,the renal tissue is divided into two portions:the cortex and medulla. The renal cortex lies immediately beneath the fibrous capsule, arch over the bases of the pyramids.It is rich in blood vessels and reddish-brown in colour.The parts from renal cortex dipping in between the pyramids are named the renal columns. The renal cortex is composed of renal glomeruli and renal tubules
The Structure of Kidney On the coronal section of a kidney, the renal tissue is divided into two portions: the cortex and medulla. The renal cortex lies immediately beneath the fibrous capsule, arch over the bases of the pyramids.It is rich in blood vessels and reddish-brown in colour. The parts from renal cortex dipping in between the pyramids are named the renal columns. The renal cortex is composed of renal glomeruli and renal tubules

The Structure of Kidney The renal medulla is deep to the cortex.It consists of a number of pale striated,conical masses,termed the renal pyramids.The bases of pyramids are directed toward the periphery of the kidney, while their apices converge towards the renal sinus,where they form prominent papillae projecting into the minor calices.The foramina on their apices are called the papillary foramina.The urine formed in the kidney passes through these foramina into the lesser calices.Two or three minor renal calices converge into one major renal calyx.Finally the major renal calices join the renal pelvis, which is flat funnel-shaped.The renal pelvis becomes narrow at the renal hilum,then passes downward to continue with the ureter at the level of the inferior extremity of the kidney
The Structure of Kidney The renal medulla is deep to the cortex.It consists of a number of pale striated, conical masses, termed the renal pyramids.The bases of pyramids are directed toward the periphery of the kidney, while their apices converge towards the renal sinus, where they form prominent papillae projecting into the minor calices.The foramina on their apices are called the papillary foramina.The urine formed in the kidney passes through these foramina into the lesser calices.Two or three minor renal calices converge into one major renal calyx. Finally the major renal calices join the renal pelvis, which is flat funnel-shaped. The renal pelvis becomes narrow at the renal hilum, then passes downward to continue with the ureter at the level of the inferior extremity of the kidney


glomerulus proximal convoluted tubule distal convoluted tubule renal artery renal vein venule peritubular capillary network loop of the nephron collecting duct