Kidney 구조, 기능

Kidney

 

Kidney 

- located ; on the left and right in the retroperitoneal(복막뒤의) space

                (우측 상복부에 있는 간의 위치 때문에 Rt.kidney가 Lt.보다 약간 아래에 있음)

- size ; in adult humans are about 12cm length

                                                       5.0~7.5cm in width

                                                       2.5cm in thickness

 

 

Renal Cortex

; 신장의 두꺼운 외피층

 

모세혈관이 세뇨관(renal tubule) 끝과 밀접하게 접촉하는 신소체(renal corpuscle : 신장소체)를 수용하고 있음

 

 

renal cortex(겉질)을 관통해 들어간 구조들은 renal medulla(속질)를 여러 개의 피라미드로 구성

⇒ renal pyramid

 

각 피라미드의 꼭지점은 renal hilum 영역을 가리킴

⇒ collecting duct(집합관)은 renal pelvis(신우)에 있는 calyx(신배, 콩팥잔)로 비워짐

⇒ renal pelvis가 채워지면 소변이 ureter(요관)로 비워짐

⇒ ureter은 kidney를 bladder와 연결해 소변이 배출되기 전까지 bladder에 보관함

 

 

Nephron  ; 신장의 기능 단위

: 혈액을 걸러 물과 전해질을 재흡수하고 독소를 배출

  (인간의 신장에는 약 백만 개의 네프론이 있음)

 

* Bowman's capsule

: cuplike structure that surrounds the glomerulus and serves as a membrane

 

* Glomerulus

: group of capillaries that serve as the filtering unit of the kidneys

 

* Proximal convoluted tubule (PCT)

: recieves the fluid that passes through the bowman's capsule

 

* Loop of henle (nephroic loop)

: follows the proximal tubule

 

* Distal convoluted tubule (DCT)

: final segment of the nephron for processing urine

 

* Collecting duct

: allows urine to be moved down to the bladder

 

[ Nephron의 역할 ]

- filter waste products

-  regulate electrolytes

- maintain renal component of acid-bace balance

 

 

- process by which blood is filtered in the glomerulus

- produced a fluid within the bowman's capsule called ultrafiltrate

 

Ultrafiltrate

- is the end product of glomerular filtration

- has osmotic pressure equal to that of plasma

  (isosmotic)

- is free of red blood cell and proteins

  (such as albumin and platelet)

 

(⇒ Ultrafiltration ; the movement of fluid though a membrane caused by a pressure gradient)

(hydrostatic or osmotic pressure)

 

 

 

Renal Blood Flow

 

 

 

Urine formation

 

(1) Glomerular filtration

 

- filtration produces fluid that is isotonic with plasma and free of RBCs and protein.

- examples of substances filtered in the glomerulus include glucose, amino-acids, small proteins, creatinine, urea, phosphate, and uric acid

 

 

(2) Reabsorption

 

- Proximal tubule에서 다시 혈액으로 가져올 것들을 재흡수

- fluid and molecules move from the porximal tubule into the particular capillary system examples include : bicarbonaste, phosphates, and calcium.

- Reabsorption is the primary process by which the kidneys produce bicarbonate to contribute to the neutralization of acid in the body

- Reabsorption of calcium also occurs in the renal tunules, which helps to maintain calcium  balance and decrease absorption of phosphate ions

- The amount of phosphate in the blood affects the level of calcium in the blood calcium and phosphate in the body react in opposite ways

  : as blood calcium levels in rise, phosphate levels fall

  A hormone called parathyroid hormone(PTH) regulates the levels of calcium and phosphorus in your blood.

 

 

(3) Tubular secretion

 

- molecules move from the peritubular capillary back into the tubule examples include hydrogen and potassium

- secretion is the primary process involved in removing acid, such as hydrogen, from the to maintain the appropriate acid-base balance in the body