anatomy of kidney (kidney ) urinary system notes

NOTES NURSING & MEDICAL STUDENTS Notes for medical student and nursing student 

kedneys :-

introduction :-

-the kidney are reddish organ shaped like kidney beans shaped .

-the are located in thea above the betwwen the peritoneum wall of the abdomen .

- since their position is behind the peritoneum of the abdomen cavity they are said retroperitoneal.

-the paired kidney are on either side of vertebral column below diaphragm.

-urine flows from kidney into ureters which empty into bladder.

                                               

                                 
            

relations of kidneys :-

superiorly :- right adrenal gland.

anteriorly:- right lobe of liver , second part of the duodenum.

posteriorly :- posterior abdominal wall muscles .

   Part of the kidney:- 

1) Renal cortex :- outer regions most of nephron structure .

2) renal medulla :- inside the cortex contains inner  collecting ducts .

3) renal pelvic -basin :- continuous with ureter .s 

4) renal columns :- extension of cortex-like material inward that separate the pyramids .

5) calyces :- cup shaped structure , extension of pelvis that funnel urine .

6) renal of fibrous capsule - a tough fibrous layer surrounding the kidney .

structure of kidney :-

-Each kidney is enclosed in a renal capsule which is surrounded by adipose tissue.

-internally of a renal medulla ,column major and minor calyces ,and a renal pelvis .

- blood enters the kidney through the renal artery and leaves through the renal vein.

 Urine :- 

-Enters papillary duct located within renal papilla .

-flows within renal sinus of kidney .

-minor calyx -major calyx -renal pelvis .

-renal pelvic connects to ureter .

- ureter connects to urinary bladder -- stores and excrete form body though urethra.

Ultrafiltration :- 

-blood moving from the heart to the kidneys splits off into capillaries inside the glomerulus these capillaries are fenestrated and open when blood is flowing at high pressure .

Nephrons :-

-the filtering units within the kidneys each kidney is made is up of -1.25 millon of them

Each nephron consists of:--

-a capillary bed called the glomerulus which filters substances from the blood.

-a small tube extending from bowman's capsule with part named in order proximal convoluted tubule loop of henle, distal convoluted tubule .

- a secondary capillary bed called the peritubular capillary bed which surround the tubule mentioned above.

Reabsorption of molecules:- 

-the filtrate that leaves bowman capsule contains subtances that the body need and cannot afford to lose in urine ( H 2 O,) salt ions glucose .

- most reabsorption within the nephron occurs in the proximal convoluted tubule ,the reabsorption of nutrients re -enter the bloodstream by way of the surroundings peritubular capillaries bed .

-the inner lining of the proximal convoluted tubule contains microvilli in order to increase surface area for reabsorption.

Diabetic urine :- 

-the healthly people all the glucose that they eat is reabsorbed back into the blood stream

from the filtrate via active transport.

- active transport mechanism have a maximum rate at which they can have move substances and the maximum is exceeded .

Blood supply of kidney :-

-Arterial supply :-  renal arteries which are the direct branches of the abdominal aorta & are large in size .

-venous drainage :- renal vein ,ends  in inferior vena cava ,the left renal vein is longer than the right.

-nerve supply :- sympathetic fibers derived from segment and parasympathetic fibers from vagus nerve .

-lymphatic drainage :- into lateral aortic nodes.