Kidney (STRUCTURE AND FUNCTIONS) (: The Guyton and Hall physiology)

STRUCTURE AND FUNCTIONS OF KIDNEY
There are two kidneys in body , Rt & Lt, lying on post abdominal wall, outside peritoneal cavity.

There weight is aprx. 150 Gm and size is clenched fist.

On medial side, there is a region called hilum through which pass blood & lymphatic vessels, nerve fibers and ureterKidney is surrounded by a protective fibrous capsule.

Each kidney has two major zones, outer thick known as cortex and part known as medulla.

Medulla is divided into multiple cone shaped tissue masses called renal pyramid.

The base of pyramid begins at junction of cortex & medulla and terminates in papilla which projects into space of renal pelvis.

Renal pelvis is funnel shaped continuation of upper end of ureter.
1- Excretion of metabolic waste products such as urea, creatinine, uric acid, Bilirubin, hormones & drugs.
2-. ELIMINATE HARMFUL FOREIGN COMPOUNDS.
Such as toxins, drugs, heavy metals, pesticides.
3- Regulation of water & electrolyte balance to maintain normal homeostasis of body by re-absorption and adjustment of rate of excretion of various substances.
4- Regulation of Arterial Pressure.

*Long term regulation by excreting variable amounts of water and sodium

and

*short term by secreting vaso-active substance (renin).

1. KIDNEY Source: The Guyton and Hall physiology Maryam Fida (o-1827)

2. STRUCTURE AND FUNCTIONS OF KIDNEY

3. There are two kidneys in body , Rt & Lt, lying on post abdominal wall, outside peritoneal cavity. There weight is aprx . 150 Gm and size is clenched fist. On medial side, there is a region called hilum through which pass blood & lymphatic vessels, nerve fibers and ureter . Physiological anatomy of kidneys

4. Kidney is surrounded by a protective fibrous capsule. Each kidney has two major zones, outer thick known as cortex and part known as medulla . Medulla is divided into multiple cone shaped tissue masses called renal pyramid .

5. The base of pyramid begins at junction of cortex & medulla and terminates in papilla which projects into space of renal pelvis. Renal pelvis is funnel shaped continuation of upper end of ureter .

6. Outer border of pelvis is divided into open-ended pouches called major calyces which extend downward to divide into minor calyces. Minor calyces collect urine from tubules of each papilla.

7. Functions of Kidneys 1- Excretion of metabolic waste products such as urea, creatinine, uric acid, Bilirubin, hormones & drugs . 2- . ELIMINATE HARMFUL FOREIGN COMPOUNDS. Such as toxins, drugs, heavy metals, pesticides . 3- Regulation of water & electrolyte balance to maintain normal homeostasis of body by re-absorption and adjustment of rate of excretion of various substances. 4- Regulation of Arterial Pressure. *Long term regulation by excreting variable amounts of water and sodium and *short term by secreting vaso -active substance (renin).

8. Functions of Kidneys 5- Regulation of acid-base balance , along- with lungs and body fluid buffers, by excreting acid (kidney is only source to excrete sulfuric / phosphoric acid ). 6- Kidneys synthesize glucose from amino. acids during prolonged fasting (gluconeogenesis). 7- Endocrine function of kidney. They secrete various hormones necessary for different functions in body. Erythropoietin Thrombopoietin Renin 1,25 – DIHYDROXYCHOLECALCIFEROL (CALCITRIOL) 8- HEMOPOIETIC FUNCTION Kidney stimulate the production of erythroctes by secreting erythropoietin. erythropoietin is the important stimulating factor for erythropoiesis. kidney also secretes another factor called thrombopoietin , which stimulate the production of thrombocytes.