kidney 콩팥 신장

[진성]

Kidney (콩팥)

콩팥(Kidney) 또는 신장(腎臟)은 척추동물에 있는 콩 형태의 배설 기관이다.

주된 역할은 피속에서 요소와 같은 대사산물과 미네랄을 여과하여

물과 함께 오줌으로 배출해 체액의 항상적 균형을 유지하는 것이다.

콩팥에 관한 동영상

Renal Anatomy 1 – Kidney

http://youtu.be/7bpTiqe5R6c?list=PLt3dMFltmHL_JCU_9HP9psWUx2L-fJqBg

Renal Anatomy 2 – Nephron

http://youtu.be/k5IF1j7b3fI?list=PLt3dMFltmHL_JCU_9HP9psWUx2L-fJqBg

목차

• 1 종별 구분

• 2 해부학적 구조

  • 2.1 신소체

  • 2.2 요세관

• 3 기능

  • 3.1 조절

  • 3.2 오줌

• 4 음식으로서의 콩팥

• 5 주석

• 6 같이보기

• 7 참고 자료

• 8 바깥 고리

종별 구분 [편집]

콩팥은 본래 무척추동물의 신관에서 유래된 것이며,

발달 정도에 따라 전신·중신·후신으로 구분한다.

전신은 신장의 원시형으로, 모든 척추동물의 발생 초기에 나타나나,

후에 퇴화하여 중신이 생긴다.

원구류만이 일생 전신을 가지며, 어류와 양서류는 유생기에만 전신을 사용한다.

중신은 어류와 양서류에서 볼 수 있는데,

중신이 되면 신구 외에 보우만 주머니가 생겨서 사구체(모세 혈관의 덩어리)를 싸며,

이 사구체에서 노폐물을 걸러 배설강으로 배출한다.

이 때 보우만 주머니가 사구체를 둘러싸고 있는 것을 말피기소체(신소체)라고 한다.

파충류 이상의 동물에서는 중신이 퇴화하고 그 뒤쪽에 후신이 나타난다.

후신은 소위 신장으로서, 네프론(신단위)으로 이루어져 있는데,

네프론은 사구체와 그것을 둘러싸고 있는 깔때기 모양의 보우만 주머니 및

거기에 이어지는 1개의 세뇨관으로 이루어져 있다.

이 세뇨관은 나선상·헤어핀상으로 구부러져 신장의 피질과 수질에 걸쳐 분포하고,

집합관으로 합류하여 신우에 이른다.

신우로부터는 수뇨관에 의해 배출강 또는 방광, 요도를 거쳐 외계로 연결되어 있다.^[1]

해부학적 구조 [편집]

인간의 신장은 복부의 뒷쪽 척추 양옆에 두개가 자리잡고 있다.

오른쪽 신장은 간 바로 아래에 위치하고 왼쪽은 횡경막아래 비장근처에 자리한다.

각 신장의 상부에는 부신이 위치한다.

복강내에서 간때문에 우신이 좌신보다 아래에 위치하고

좌신이 약간 중앙에 위치하는 좌우 불균형이 나타난다.

길이 10 cm, 너비 5 cm, 두께 3 cm 정도의 강낭콩의 모양이다.

후복막에 위치하고 대략 12번 흉추와 3번 요추 사이에 있고 좌신이 약간 더 크다.

내부에는 약 100만 개의 네프론(신단위)이 밀집해 있으며,

여기에 분포하는 혈관과 함께 결합 조직의 피막으로 둘러싸여 있다.

네프론은 그 한쪽 끝에 신소체라는 구상(球狀)의 구조가 있으며,

거기에서 가늘고 긴 관(요세관)이 구불구불 뻗어 있다.

관의 말단은 다른 네프론 관과 합류하여 약간 굵은 관(집합관)이 되고,

그 말단은 신우로 열려 있다.^[2]

신소체 [편집]

이 부분의 본문은 신소체입니다.

신소체(腎小體)는 지름이 0.15 ~ 0.25mm인 구체(球體)이다.

내부에는 세동맥에서 분기한 모세혈관이 실패 모양으로 들어 있으며,

이것이 이중 막으로 둘러싸여 있다.

요세관 [편집]

신소체에서 여과된 액체는 요세관을 통과하는 사이에 그 함유 성분의 거의 대부분이

재흡수된다고 할 수 있다.

왜냐하면 신소체에서 여과되는 양은 하루에 180ℓ가 넘는데,

하루에 배출되는 오줌의 양은 약 1.5ℓ에 불과하다.

따라서 여과된 것의 99% 이상이 재흡수된다고 할 수 있다.

신소체에서 나온 액체는 먼저 요세관의 근위 곡부에 유입되는데,

여기에서 약 85%가 재흡수된다.

이 재흡수는 전신의 상태와 관계없이 유용한 것은 모두 받아들이기 때문에

불가피적 재흡수라고 한다.

결국 매분 약 20㎖의 액체만이 먼저 보내지고,

헨레의 함정이나 원위 곡부에서 그때의 체액 성질에 대응하여 섬세한 조절이 되기 때문에

이를 선택적 재흡수라고 한다.

요세관에서 흡수되는 물질 가운데 양이 가장 많은 것은 수분이다.

따라서 신체의 수분 함유량의 조절은 신장의 중요한 기능 중의 하나이다.

기타 물질의 재흡수는 거의 세 종류로 나눌 수 있다.

첫째는 혈액 속의 농도가 일정 수준에 달할 때까지 적극적으로 흡수가 계속되는 것으로,

포도당·아미노산·비타민 C· Na+·Cl- 등 생체에 없어서는 안 되는 중요한 물질은 모두

이 유형에 속하며, 이를 고역치 물질이라 한다.

둘째는 첫 번째 정도는 아니지만 혈액 속에 있는 것이 농도가 높아도 다시 어느 정도

재흡수되는 것으로, 인산염·황산염·요산·요소 등이 여기에 속한다.

셋째는 설령 혈액 속에 있는 것이 농도가 낮아도 거의 또는 결코 재흡수되지 않는 것으로,

비역치 물질이라 한다. 여기에는 크레아티닌이나 암모니아 등이 있다.

요세관의 주된 기능은 재흡수인데,

일부 물질은 반대로 모세혈관에서 요세관 속으로 방출된다.

이것을 요세관 분비라고 한다.

수소 이온·나트륨 이온, 유기성 산이나 염기, 요소 등이 여러 부위에서 분비된다.

기능 [편집]

신장의 오줌 생성 및 조절 문서를 참고하십시오.

조절 [편집]

신장 자체에 갖추어져 있는 조절 능력으로,

혈압이나 혈액 상태 등에 의해 자동적으로 여과나 재흡수 정도가 미묘하게 조절되고 있다.

건강한 상태에서의 신장 기능의 조절은 그 대부분이 자율적으로 행해진다.

신장에도 교감 신경과 부교감 신경이 분포되어 있다.

교감 신경을 자극하면 오줌량이 줄어든다.

이것은 동맥이 수축하여 신소체에서의 여과량이 줄었기 때문이다.

부교감 신경의 작용은 알려진 바 없다.

조혈호르몬인 에리스로포이에틴을 비롯 Urodilantin, 비타민 D 등을 생성한다.

대부분이 원위 곡부 요세관에서의 재흡수에 관계되어 있다.

하수체 후엽 호르몬은 수분의 재흡수를 촉진시키는 작용을 한다.

부신 피질 호르몬 가운데 알드스테론은 이온 상태가 된 미네랄 재흡수를 조절한다.

상피 소체 호르몬은 인의 재흡수를 촉진한다.

그 밖에 갑상선 호르몬이나 하수체 전엽 호르몬도 관계하고 있다.

오줌 [편집]

신진대사로 생긴 각종 대사산물을 배출한다.

단백질 대사산물인 요소, 핵산 대사산물인 요산 그리고 물을 배출한다.

오줌은 하루에 남성의 경우 약 1.5ℓ, 여성은 약 1.2ℓ를 배출한다.

pH는 평균 6으로, 약산성이다.

정상적인 비중은 1.017-1.020으로,

요붕증(尿崩症) 등으로 인해 오줌량이 많아지면 1.005로 엷어지고,

반대로 네프로제 등으로 인해 오줌량이 줄어들면 1.030으로 높아진다.

오줌으로 배출되는 고형 성분의 양은 하루에 약 60g 정도인데,

이 양은 진한 오줌이든 묽은 오줌이든 거의 같다.

오줌의 색깔은 단백질이 분해되어 생기는 우로크롬이 함유되어 있기 때문에

노란빛을 띠고 있다.

음식으로서의 콩팥 [편집]

스웨덴의 돼지고기와 콩팥 스튜 - Hökarpanna

짐승의 콩팥은 다른 잡육과 곁들여 요리하여 먹을 수 있다.

콩팥은 일반적으로 불에 굽거나 살짝 튀기지만,

더 복잡한 요리의 경우 맛을 돋우는 양념으로 끓인다.

수많은 요리 준비에서 섞음 요리로서 콩팥은 고기나 간 조각들과 함께 한다.

요리에는 영국의 스테이크 앤 키드니 파이, 스웨덴의 hökarpanna,

프랑스의 rognons de veau sauce moutarde, 스페인의 riñones al Jerez를 포함한다.^[3]

주석 [편집]

1. 이동 ↑ '콩팥, 비뇨기의 구조', 《글로벌 세계 대백과》

2. 이동 ↑ '신장의 내부 구조, 비뇨기의 구조', 《글로벌 세계 대백과》

3. 이동 ↑ Rognons dans les recettes (프랑스어)

같이보기[편집]

• 신장의 오줌 생성 및 조절

신장의 오줌 생성 및 조절

신장의 오줌 생성 및 조절 과정을 나타낸 모식도

신장은 오줌을 생성하는 기능을 하며,

체액의 항상성 조절에 매우 중요한 역할을 수행한다.

이는 다양한 수용기, 호르몬 등에 의해 조절된다.

목차

• 1 사구체의 역할

• 2 근위세뇨관의 역할

• 3 헨레 고리의 역할

  • 3.1 하행지

  • 3.2 상행지

• 4 원위세뇨관의 역할

• 5 집합관의 역할

• 6 주석

사구체의 역할 [편집]

사구체에서는 원뇨의 여과가 일어난다.

여과는 사구체로 들어가는 입수소동맥과 사구체에서 나가는 출수소동맥 사이의

혈압 차이에 의해 일어나게 된다.

사구체 모세혈관은 투과성이 매우 높아 여과가 잘 일어날 수 있게 한다.

혈압이나 혈관 직경의 조절로 여과율이 조정될 수 있다.

사구체에서의 여과에 관여하는 주요한 힘은 다음 세 가지가 있다.

사구체 모세혈관압 : 모세혈관에서 보먼주머니로의 여과를 유도한다.

혈장 교질 삼투압 : 여과되지 않는 단백질 등의 용질로 인해 혈장의 삼투농도가

더 높은 데에서 기인하며, 여과를 저해한다.

보먼주머니 정수압 : 여과를 저해한다.

이 세 힘을 합산하여 순여과압을 구할 수 있고,

사구체막의 특성에 따른 여과계수인 를 곱하면 사구체 여과율(GFR)을 구할 수 있다.

이를 식으로 나타내면

이다 (P : 순여과압).

보통 사람의 경우 신장 전체의 사구체를 통하여 평균적으로 120ml/min의 총 GFR로

매일 170L 정도의 사구체 여과가 일어난다.^[1]

위의 세 가지 힘 중, 직접적으로 조절될 수 있는 것은 사구체 모세혈관압 뿐이다.

이는 입수소동맥의 지름 조절로 조정되는데, 출수소동맥의 지름은 비교적 일정하게

유지되므로 입수소동맥의 지름이 커지면 사구체 혈압이 높아져 여과율이 높아지고,

지름이 작아지면 반대로 사구체 모세혈관압이 낮아져 여과율이 낮아질 것이다.

근위세뇨관의 역할 [편집]

근위세뇨관은 거의 대부분의 재흡수 과정을 담당한다.

근위세뇨관에서 일어나는 재흡수 과정은 조절의 주 대상이 아니며, 항상 일어난다.

 근위세뇨관에서는 포도당과 아미노산 등 영양소, 소듐 이온, 염소 이온, 물, 요소 등의

재흡수가 일어난다. 근위세뇨관의 상피세포에서는 소듐-포타슘 펌프를 이용하여 소듐

이온을 간질액으로 능동적으로 수송하는데,

이렇게 수송된 소듐 이온들은 모세혈관을 통해 재흡수된다.

한편 세포내의 소듐 이온 농도는 낮아졌기 때문에 세뇨관과 세포 사이에

농도 기울기가 생기게 되는데,

이를 통해 포도당과 아미노산 등이 2차 능동수송으로 재흡수된다.

정상적인 혈중 포도당 및 아미노산 범위에서, 포도당과 아미노산은 100% 재흡수된다.

혈중 포도당 농도가 일정 범위 이상으로 높아져 재흡수 용량을 초과하게 되면 오줌에서

포도당이 검출되는데, 이를 당뇨병이라고 한다.

소듐 이온이 흡수됨에 따라 염소 이온이 전기적 기울기에 의해 재흡수되고,

삼투에 의해 물 또한 재흡수된다.

물이 재흡수됨에 따라 상대적으로 세뇨관의 포타슘 이온과 요소 농도도 높아져

확산을 통해 재흡수된다.^[2]

근위세뇨관에서는 여과된 물과 소듐 및 염소 이온의 2/3, 포타슘 이온의 65%, 요소의 50%,

인산 이온의 80%, 시트르산의 70~90%가 재흡수된다.

헨레 고리의 역할 [편집]

헨레 고리(Henle's loop)는 근위세뇨관과 원위세뇨관을 잇는 고리 형태의 관으로,

하행지와 상행지로 구분된다.

헨레 고리의 길이에 따라 네프론이 분류되는데,

헨레 고리가 신장의 피질 부분에만 존재하는 것을 피질네프론,

신장의 수질 부분까지 들어가는 것을 수질옆네프론이라고 한다.

두 네프론은 기능에 주요한 차이가 있는데,

이는 신장이 피질에서 수질에 이르는 큰 농도기울기를 가지고 있기 때문이다.

신장의 피질은 보통의 혈액과 비슷한 약 300mOm/L의 삼투농도를 가지지만,

신장의 수질은 인간의 경우 1200mOm/L까지 농축된 삼투농도를 가진다.

이는 포유류가 자신의 체액보다 훨씬 높은 농도의 오줌을 배출할 수 있는 이유이며,

건조한 지역에 사는 동물들은 그 농도가 더 높으며 피질네프론에 비해 수질옆네프론의

비율이 높아진다. 예컨데 호주의 껑충쥐는 자신의 체액에 비해 25배나 농도가 높은

9300mOm/L의 오줌을 배출할 수 있다.^[3]

하행지 [편집]

헨레 고리의 하행지는 염류나 다른 저분자들에 대한 투과성이 매우 낮은 반면

물이 투과할 수 있는 통로인 아쿠아포린을 발현하여 물에 대한 투과성은 높다.^[3]

따라서 헨레 고리의 하행지가 신장의 수질 쪽으로 들어감에 따라 주위의 삼투농도는

더욱 높아지고, 용질의 이동이 불가하므로 삼투 현상에 의해

물이 고리 외부로 빠져나가 재흡수된다.

상행지 [편집]

헨레 고리의 상행지는 하행지와는 반대로 아쿠아포린이 거의 발현되지 않아

물에 대한 투과성이 매우 낮다.

이는 생명체에서는 매우 드문 경우이다.

반면 소듐와 염소 이온에 대한 투과성은 있다.

하행지를 따라 내려오면서 농축된 오줌이 상행지를 따라 올라가면,

주위 환경에 비해 상행지 내부의 오줌이 고농도가 된다.

그러나 물의 이동은 불가능하므로 소듐와 염소 이온만이 빠져나가게 된다.

상행지는 수질 쪽에 더 가까운 얇은 부분과 피질 쪽에 더 가까운 굵은 부분으로 나뉘는데,

얇은 부분에서는 확산에 의해 염화소듐이 재흡수되지만,

굵은 부분에서는 능동 수송 기작도 염화소듐의 재흡수에 기여한다.^[3]

상행지를 지나 원위세뇨관으로 들어가는 오줌은 다시 묽은 상태가 된다.

원위세뇨관의 역할 [편집]

원위세뇨관은 포타슘과 소듐 이온 농도,

그리고 혈압 변화에 대한 항상성 조절의 주요한 역할을 담당한다.

원위세뇨관에서는 포타슘 이온의 분비가 일어난다.

세뇨관세포에서 소듐-포타슘 펌프를 이용하여 간질액으로 소듐 이온을,

세포 내로 포타슘 이온을 운반하고 이에 따라 세포 내의 포타슘 농도가 높아져

세뇨관강으로 포타슘의 확산이 일어나게 된다.

같은 과정에서 소듐 이온은 재흡수되게 되며,

이 때 전기적 기울기에 따른 염소 이온의 재흡수와 삼투 기울기에 따른

물의 재흡수도 일어난다.

이 과정은 알도스테론에 의해 조절된다.

부신피질에서 분비되는 스테로이드계 호르몬인 알도스테론은 세뇨관세포의 막에

소듐-포타슘 펌프의 발현을 증가시켜 포타슘의 분비와 염화소듐과 물의 재흡수를

촉진한다.

알도스테론의 분비를 촉진하는 요인은 다음과 같다.

• 낮은 혈장 소듐 이온 농도

• 동맥 혈압의 감소

• 세포외액 부피의 감소

• 혈장 포타슘 이온 농도의 증가

이 중 마지막 요인(포타슘 이온 농도의 증가)을 제외한 세 요인은,

 레닌-안지오텐신-알도스테론 계의 활성화를 통해 알도스테론의 분비를 촉진하고,

혈장 포타슘 이온 농도의 증가는 직접적으로 부신피질을 자극하여

알도스테론 분비를 유도한다.

한편, 원위세뇨관은 알도스테론과 길항적 작용을 하는 심방 나트륨이뇨 펩티드(ANP)

의 작용 지점이기도 하다.

심방 나트륨이뇨 펩티드는 세뇨관 세포의 소듐 이온 재흡수를 억제하고 알도스테론의

분비 역시 억제하여 소듐 이온의 오줌으로의 배출을 촉진한다.

집합관의 역할 [편집]

바소프레신 문서를 참고하십시오.

집합관은 여러 네프론에서 나온 세뇨관들이 모여 신우에 이르는 관이다.

집합관은 체내 수분량의 항상성 조절 기작이 작용하는 주요한 지점인데,

이를 조절하는 호르몬은 뇌하수체 후엽에서 분비되는

항이뇨호르몬(바소프레신, ADH)이다.

ADH의 분비를 촉진하는 주 요인은 혈액의 삼투농도 증가로,

갑자기 많은 땀을 흘린 경우 등으로 혈액의 삼투농도가 증가하면

시상하부의 삼투수용기가 이를 인지, ADH 분비를 촉진하게 된다.

증가된 ADH는 집합관 세포 표면에 아쿠아포린의 발현을 증가시키는데,

이는 아쿠아포린 저장 소낭이 막에 융합하는 것을 촉진함으로써 이루어진다.

ADH 분비 수준이 낮을 때는 아쿠아포린이 다시 소낭에 저장되어 표면에

발현되지 않는다.

아쿠아포린의 발현이 증가되어 집합관의 물 투과성이 증가하면,

집합관이 신장의 피질에서 수질로 진행함에 따라 높아지는 주위의 삼투농도에 의해

물의 재흡수가 촉진되고 결과적으로 오줌의 양이 줄어들어 물을 보존하게 된다.

아쿠아포린의 발현이 적으면 물의 재흡수량이 적어지고 오줌의 양이 늘어난다.

집합관의 수질 부위는 요소에 대해 투과성을 띄는데,

이 때 집합관 내의 요소 농도는 물의 재흡수로 인해 상대적으로

높아져 있기 때문에 확산에 의해 신장의 수질로 요소가 일부분 재흡수된다.

이는 신장의 피질-수질 농도기울기를 유지하는데 도움을 준다.^[3]

***********************************************

Kidney
Human kidneys viewed from behind with spine removed
Details
Latin	Ren
Greek	Nephros
System	Urinary system and endocrine system
Artery	Renal artery
Vein	Renal vein
Nerve	Renal plexus
Identifiers
MeSH	A05.810.453
Dorlands /Elsevier	Kidney
TA	A08.1.01.001
FMA	7203
Anatomical terminology

The kidneys are bean-shaped organs that serve several essential regulatory roles in vertebrates.

They remove excess organic molecules from the blood,

and it is by this action that their best-known function is performed:

the removal of waste products of metabolism.

They are essential in the urinary system and also serve homeostatic functions such as the

regulation of electrolytes, maintenance of acid–base balance, and regulation of blood pressure

(via maintaining salt and water balance).

They serve the body as a natural filter of the blood, and remove water soluble wastes,

which are diverted to the bladder.

In producing urine, the kidneys excrete wastes such as urea and ammonium,

and they are also responsible for the reabsorption of water, glucose, and amino acids.

The kidneys also produce hormones including calcitriol, erythropoietin, and the enzyme renin,

the last of which indirectly acts on the kidney in negative feedback.

Located at the rear of the abdominal cavity in the retroperitoneal space, the kidneys receive

blood from the paired renal arteries, and drain into the paired renal veins.

Each kidney excretes urine into a ureter,  that empties into the bladder.

Renal physiology is the study of kidney function, while nephrology is the medical specialty

concerned with kidney diseases.

Diseases of the kidney are diverse, but individuals with kidney disease frequently display

characteristic clinical features.

Common clinical conditions involving the kidney include the nephritic and nephrotic syndromes,

renal cysts, acute kidney injury, chronic kidney disease, urinary tract infection, nephrolithiasis,

and urinary tract obstruction.^[1]

Various cancers of the kidney exist; the most common adult renal cancer is renal cell carcinoma.

Cancers, cysts, and some other renal conditions can be managed with removal of the kidney,

or nephrectomy.

When renal function, measured by glomerular filtration rate, is persistently poor, dialysis and

kidney transplantation may be treatment options.

Although they are not normally harmful, kidney stones can be painful.

Contents

• 1 Structure

  • 1.1 Location

  • 1.2 Structure

  • 1.3 Blood supply

  • 1.4 Histology

  • 1.5 Innervation

  • 1.6 Development

• 2 Functions

  • 2.1 Excretion of wastes

  • 2.2 Reabsorption of vital nutrients

  • 2.3 Acid-base homeostasis

  • 2.4 Osmolality regulation

  • 2.5 Blood pressure regulation

  • 2.6 Hormone secretion

  • 2.7 Calculations

    • 2.7.1 Filtration Fraction

    • 2.7.2 Renal Clearance

  • 2.8 Mathematical modelling

• 3 Clinical significance

  • 3.1 Congenital

  • 3.2 Acquired

  • 3.3 Diagnosis

    • 3.3.1 Clinical

    • 3.3.2 Laboratory

    • 3.3.3 Imaging

    • 3.3.4 Biopsy

• 4 In other animals

  • 4.1 Evolutionary adaptation

• 5 Society and culture

  • 5.1 Kidneys as food

• 6 History

• 7 See also

• 8 Additional Images

• 9 References

• 10 External links

Structure [edit]

Location [edit]

In humans the kidneys are located in the abdominal cavity,

more specifically in the paravertebral gutter and lie in a retroperitoneal position at a slightly

oblique angle.

There are two kidneys, one on each side of the spine.^[2]

The asymmetry within the abdominal cavity caused by the position of the liver,

typically results in the right kidney being slightly lower and smaller than the left,

and being placed slightly more to the middle than the left kidney.^[3][4][5]

The left kidney is approximately at the vertebral level T12 to L3,^[6]

and the right is slightly lower.

Surface projections of the organs of the trunk, showing kidneys at the level of T12 to L2.

A CT scan in which the kidneys are shown

The right kidney sits just below the diaphragm and posterior to the liver,

the left sits below the diaphragm and posterior to the spleen.

Resting on top of each kidney is an adrenal gland.

The upper parts of the kidneys are partially protected by the eleventh and twelfth ribs.

Each kidney together with its adrenal gland is surrounded by two layers of fat

(the perirenal and pararenal fat) and the renal fascia.

Each adult kidney weighs between 125 and 170 grams in males and between 115 and 155 grams

in females.^[7]

Structure [edit]

1. Renal pyramid • 2. Interlobular artery • 3. Renal artery

 • 4. Renal vein 5. Renal hilum • 6. Renal pelvis

• 7. Ureter • 8. Minor calyx • 9. Renal capsule

• 10. Inferior renal capsule • 11. Superior renal capsule • 12. Interlobular vein

• 13. Nephron • 14. Minor calyx •

15. Major calyx • 16. Renal papilla • 17. Renal column

The kidney has a bean-shaped structure having a convex and a concave surface.

A recessed area on the concave surface, is the renal hilum,

where the renal artery enters the kidney, and the renal vein and ureter leave.

The kidney is surrounded by tough fibrous tissue, the renal capsule,

which is itself surrounded by perinephric fat, renal fascia (of Gerota) and paranephric fat.

The anterior (front) border of these tissues is the peritoneum,

while the posterior (rear) border is the transversalis fascia.

The superior border of the right kidney is adjacent to the liver;

and the spleen, for the left kidney.

Therefore, both move down on inhalation 흡입.

The kidney is approximately 11–14 cm (4.3–5.5 in) in length, 6 cm (2.4 in) wide

and 4 cm (1.6 in) thick.

The substance, or parenchyma, of the kidney is divided into two major structures:

the outer renal cortex and the inner renal medulla.

Grossly, these structures take the shape of 8 to 18 cone-shaped renal lobes,

each containing renal cortex surrounding a portion of medulla called a renal pyramid

(of Malpighi).^[7]

Between the renal pyramids are projections of cortex called renal columns (or Bertin columns).

Nephrons, the urine-producing functional structures of the kidney, span the cortex and medulla.

The initial filtering portion of a nephron is the renal corpuscle, located in the cortex,

which is followed by a renal tubule that passes from the cortex deep into the medullary

pyramids. Part of the renal cortex,

a medullary ray is a collection of renal tubules that drain into a single collecting duct.

The tip, or papilla, of each pyramid empties urine into a minor calyx;

minor calyces empty into major calyces, and major calyces empty into the renal pelvis,

which becomes the ureter.

At the hilum, the ureter and renal vein exit the kidney while the renal artery enters.

Surrounding these structures is hilar fat and lymphatic tissue with lymph nodes.

The hilar fat is contiguous with a fat-filled cavity called the renal sinus.

The renal sinus collectively contains the renal pelvis and calyces and separates these

structures from the renal medullary tissue.^[8]

Blood supply [edit]

3D-rendered computed tomography, showing renal arteries and veins.

The kidneys receive blood from the renal arteries, left and right,

which branch directly from the abdominal aorta. Despite their relatively small size,

the kidneys receive approximately 20% of the cardiac output.^[7]

Each renal artery branches into segmental arteries, dividing further into interlobar arteries,

which penetrate the renal capsule and extend through the renal columns between the renal

pyramids.

The interlobar arteries then supply blood to the arcuate arteries that run through the boundary

of the cortex and the medulla.

Each arcuate artery supplies several interlobular arteries that feed into the afferent arterioles

that supply the glomeruli.

The medullary interstitium is the functional space in the kidney beneath the individual filters

(glomeruli), which are rich in blood vessels.

The interstitium absorbs fluid recovered from urine.

Various conditions can lead to scarring and congestion of this area,

which can cause kidney dysfunction and failure.

After filtration occurs the blood moves through a small network of venules that converge into

interlobular veins.

As with the arteriole distribution the veins follow the same pattern,

the interlobular provide blood to the arcuate veins then back to the interlobar veins,

which come to form the renal vein exiting the kidney for transfusion for blood.

Histology [edit]

Microscopic photograph of the renal medulla  Microscopic photograph of the renal cortex

Renal histology studies the structure of the kidney as viewed under a microscope.

Various distinct cell types are present, including:

• Kidney glomerulus parietal cell

• Kidney glomerulus podocyte

• Kidney proximal tubule brush border cell

• Loop of Henle thin segment cell

• Thick ascending limb cell

• Kidney distal tubule cell

• Collecting duct principal cell

• Collecting duct intercalated cell

• Interstitial kidney cells

The renal artery enters into the kidney at the level of first lumbar vertebra just below

the superior mesenteric artery.

As it enters the kidney it divides into branches:

first the segmental artery, which divides into 2 or 3 lobar arteries,

then further divides into interlobar arteries, which further divide into the arcuate artery,

which leads into the interlobular artery, which form afferent arterioles.

The afferent arterioles form the glomerulus

(network of capillaries enclosed in Bowman's capsule).

From here, efferent arterioles leaves the glomerulus and divide into peritubular capillaries,

which drain into the interlobular veins and then into arcuate vein and then into interlobar vein,

which runs into lobar vein,

which opens into the segmental vein and which drains into the renal vein,

and then from it blood moves into the inferior vena cava 하행대정맥.

Innervation 신경분포[edit]

The kidney and nervous system communicate via the renal plexus,

whose fibers course along the renal arteries to reach each kidney.^[9]

Input from the sympathetic nervous system triggers vasoconstriction in the kidney,

thereby reducing renal blood flow.^[9]

The kidney also receives input from the parasympathetic nervous system,

by way of the renal branches of the vagus nerve (cranial nerve X);

the function of this is yet unclear.^[9][10]

Sensory input from the kidney travels to the T10-11 levels of the spinal cord and is sensed in

the corresponding dermatome.^[9]

Thus, pain in the flank region may be referred from corresponding kidney.^[9]

Development [edit]

Main article: Kidney development

The mammalian kidney develops from intermediate mesoderm. Kidney development,

also called nephrogenesis, proceeds through a series of three successive phases,

each marked by the development of a more advanced pair of kidneys:

the pronephros, mesonephros, and metanephros.^[11]

Functions [edit]

Main article: Renal physiology

The kidney participates in whole-body homeostasis, regulating acid-base balance, electrolyte

concentrations, extracellular fluid volume, and blood pressure.

The kidney accomplishes these homeostatic functions both independently and in concert

with other organs, particularly those of the endocrine system.

Various endocrine hormones coordinate these endocrine functions; these include renin,

angiotensin II, aldosterone, antidiuretic hormone, and atrial natriuretic peptide, among others.

Many of the kidney's functions are accomplished by relatively simple mechanisms of filtration,

reabsorption, and secretion, which take place in the nephron.

Filtration, which takes place at the renal corpuscle, is the process by which cells and large

proteins are filtered from the blood to make an ultrafiltrate that eventually becomes urine.

The kidney generates 180 liters of filtrate a day, while reabsorbing a large percentage,

allowing for the generation of only approximately 2 liters of urine.

Reabsorption is the transport of molecules from this ultrafiltrate and into the blood.

Secretion is the reverse process, in which molecules are transported in the opposite direction,

from the blood into the urine.

Excretion of wastes [edit]

The kidneys excrete a variety of waste products produced by metabolism into the urine.

These include the nitrogenous wastes urea, from protein catabolism, and uric acid,

from nucleic acid metabolism.

The ability of mammals and some birds to concentrate wastes into a volume of urine much

smaller than the volume of blood from which the wastes were extracted is dependent on an

elaborate countercurrent multiplication mechanism.

This requires several independent nephron characteristics to operate:

a tight hairpin configuration of the tubules,

water and ion permeability in the descending limb of the loop,

water impermeability in the ascending loop,

and active ion transport out of most of the ascending limb.

In addition, passive countercurrent exchange by the vessels carrying the blood supply

to the nephron is essential for enabling this function.

Reabsorption of vital nutrients 재흡수 [edit]

Glucose at normal plasma levels is completely reabsorbed in the proximal tubule.

The mechanism for this is the Na⁺/glucose cotransporter.

A plasma level of 350 mg/dL will fully saturate the transporters and glucose will be lost in

the urine.

A plasma glucose level of approximately 160 is sufficient to allow glucosuria,

which is an important clinical clue to diabetes mellitus 당뇨병.

Amino acids are reabsorbed by sodium dependent transporters in the proximal tubule.

Hartnup disease is a deficiency of the tryptophan amino acid transporter,

which results in pellagra.^[12]

Location of Reabsorption	Reabsorbed nutrient	Notes
Early proximal tubule	Glucose (100%), amino acids (100%), bicarbonate (90%), Na+ (65%), Cl−, phosphate and H2O (65%)	PTH will inhibit phosphate excretion AT II stimulates Na+, H2O and HCO3− reabsorption.
Thin descending loop of Henle	H2O	Reabsorbs via medullary hypertonicity and makes urine hypertonic.
Thick ascending loop of Henle	Na+ (10–20%), K+, Cl−; indirectly induces para cellular reabsorption of Mg2+, Ca2+	This region is impermeable to H2O and the urine becomes less concentrated as it ascends.
Early distal convoluted tubule	Na+, Cl−	PTH causes Ca2+ reabsorption.
Collecting tubules	Na+(3–5%), H2O	Na+ is reabsorbed in exchange for K+, and H+, which is regulated by aldosterone. ADH acts on the V2 receptor and inserts aquaporins on the luminal side

Pregnancy reduces the reabsorption of glucose and amino acids.

Acid-base homeostasis [edit]

Main article: Acid-base homeostasis

Two organ systems, the kidneys and lungs, maintain acid-base homeostasis,

which is the maintenance of pH around a relatively stable value.

The lungs contribute to acid-base homeostasis by regulating carbon dioxide (CO₂) concentration.

The kidneys have two very important roles in maintaining the acid-base balance:

to reabsorb and regenerate bicarbonate from urine,

and to excrete hydrogen ions and fixed acids (anions of acids) into urine.

Osmolality regulation [edit]

Any significant rise in plasma osmolality is detected by the hypothalamus,

which communicates directly with the posterior pituitary gland.

An increase in osmolality causes the gland to secrete antidiuretic hormone (ADH),

resulting in water reabsorption by the kidney and an increase in urine concentration.

The two factors work together to return the plasma osmolality to its normal levels.

ADH binds to principal cells in the collecting duct that translocate aquaporins to the membrane,

allowing water to leave the normally impermeable membrane and be reabsorbed into the body

by the vasa recta, thus increasing the plasma volume of the body.

There are two systems that create a hyperosmotic medulla and thus increase the body plasma

volume: Urea recycling and the 'single effect.'

Urea is usually excreted as a waste product from the kidneys.

However, when plasma blood volume is low and ADH is released the aquaporins that are opened

are also permeable to urea.

This allows urea to leave the collecting duct into the medulla creating a hyperosmotic solution

that 'attracts' water.

Urea can then re-enter the nephron and be excreted or recycled again depending on whether

ADH is still present or not.

The 'Single effect' describes the fact that the ascending thick limb of the loop of Henle is not

permeable to water but is permeable to NaCl.

This allows for a countercurrent exchange system whereby the medulla becomes increasingly

concentrated, but at the same time setting up an osmotic gradient for water to follow should

the aquaporins of the collecting duct be opened by ADH.

Blood pressure regulation 혈압조절 [edit]

Main articles: Blood pressure regulation and Renin-angiotensin system

Although the kidney cannot directly sense blood, long-term regulation of blood pressure

predominantly depends upon the kidney.

This primarily occurs through maintenance of the extracellular fluid compartment,

the size of which depends on the plasma sodium concentration.

Renin is the first in a series of important chemical messengers that make up

the renin-angiotensin system.

Changes in renin ultimately alter the output of this system,

principally the hormones angiotensin II and aldosterone.

Each hormone acts via multiple mechanisms,

but both increase the kidney's absorption of sodium chloride,

thereby expanding the extracellular fluid compartment and raising blood pressure.

When renin levels are elevated, the concentrations of angiotensin II and aldosterone increase,

leading to increased sodium chloride reabsorption,

expansion of the extracellular fluid compartment, and an increase in blood pressure.

Conversely, when renin levels are low, angiotensin II and aldosterone levels decrease,

contracting the extracellular fluid compartment, and decreasing blood pressure.

Hormone secretion [edit]

The kidneys secrete a variety of hormones, including erythropoietin, and the enzyme renin.

 Erythropoietin is released in response to hypoxia (low levels of oxygen at tissue level)

in the renal circulation.

It stimulates erythropoiesis (production of red blood cells) in the bone marrow.

Calcitriol, the activated form of vitamin D,

promotes intestinal absorption of calcium and the renal reabsorption of phosphate.

Part of the renin–angiotensin–aldosterone system,

renin is an enzyme involved in the regulation of aldosterone levels.

Calculations [edit]

Calculations of kidney performance are an important part of physiology and can be estimated

using the calculations below.

Filtration Fraction [edit]

The filtration fraction is the amount of plasma that is actually filtered through the kidney.

This can be defined using the equation:

FF=GFR/RPF

• FF is the filtration fraction

• GFR is the glomerular filtration rate

• RPF is the renal plasma flow

Normal human FF is 20%.

Renal Clearance [edit]

Main article: Renal function

Renal clearance is the volume of plasma from which the substance is completely cleared

from the blood per unit time.

C_x=(U_x)V/P_x

• C_x is the clearance of X (normally in units of mL/min.

• U_x is the urine concentration of X.

• P_x is the plasma concentration of X.

• V is the urine flow rate.

Mathematical modelling [edit]

The kidney is a very complex organ and numerical modelling has been used to better understand

kidney function at several scales, including fluid uptake and secretion.^[13][14]

Clinical significance [edit]

Main article: Nephropathy

Nephropathy 신장애, 신증(腎症), is kidney disease or damage to a kidney.

Nephrosis is non-inflammatory nephropathy and nephritis is inflammatory kidney disease.

Nephrology is the speciality that deals with kidney function and disease.

Medical terms related to the kidneys commonly use terms such as renal and the prefix nephro-.

The adjective renal, meaning related to the kidney, is from the Latin rēnēs, meaning kidneys;

the prefix nephro- is from the Ancient Greek word for kidney, nephros (νεφρός).^[15]

For example, surgical removal of the kidney is a nephrectomy,

while a reduction in kidney function is called renal dysfunction신기능장애.

Congenital 선천적 [edit]

• Congenital hydronephrosis

• Congenital obstruction of urinary tract

• Duplex kidneys, or double kidneys, occur in approximately 1% of the population. This occurrence normally causes no complications, but can occasionally cause urine infections.^[16][17]

• Duplicated ureter occurs in approximately one in 100 live births

• Horseshoe kidney occurs in approximately one in 400 live births

• Nutcracker Syndrome

• Polycystic kidney disease

  • Autosomal dominant polycystic kidney disease afflicts patients later in life. Approximately one in 1000 people will develop this condition

  • Autosomal recessive polycystic kidney disease is far less common, but more severe, than the dominant condition. It is apparent in utero or at birth.

• Renal agenesis. Failure of one kidney to form occurs in approximately one in 750 live births. Failure of both kidneys to form is invariably fatal.

• Renal dysplasia

• Unilateral small kidney

• Multicystic dysplastic kidney occurs in approximately one in every 2400 live births

• Ureteropelvic Junction Obstruction or UPJO; although most cases appear congenital, some appear to be an acquired condition^[18]

Acquired [edit]

Drawing of an enlarged kidney by John Hunter.

• Diabetic nephropathy

• Glomerulonephritis

• Hydronephrosis is the enlargement of one or both of the kidneys caused by obstruction of the flow of urine.

• Interstitial nephritis

• Kidney stones (nephrolithiasis) are a relatively common and particularly painful disorder.

• A chronic condition can result in scars to the kidneys.

• The removal of kidney stones involves ultrasound treatment to break up the stones into smaller pieces,

• which are then passed through the urinary tract.

• One common symptom of kidney stones is a sharp to disabling pain in the middle and sides of the lower back or groin.

• Kidney tumour

  • Wilms tumor

  • Renal cell carcinoma

• Lupus nephritis

• Minimal change disease

• In nephrotic syndrome, the glomerulus has been damaged so that a large amount of protein in the blood enters the urine.

• Other frequent features of the nephrotic syndrome include swelling, low serum albumin, and high cholesterol.

• Pyelonephritis is infection of the kidneys and is frequently caused by complication of a urinary tract infection.

• Renal failure

  • Acute renal failure

  • Stage 5 Chronic Kidney Disease

Kidney Failure

Main article: Renal failure

Generally, humans can live normally with just one kidney, as one has more functioning renal

tissue than is needed to survive. Only when the amount of functioning kidney tissue is greatly

diminished does one develop chronic kidney disease.

Renal replacement therapy, in the form of dialysis or kidney transplantation,

is indicated when the glomerular filtration rate has fallen very low or

if the renal dysfunction leads to severe symptoms.

Diagnosis [edit]

Clinical [edit]

Many renal diseases are diagnosed on the basis of classical clinical findings.

A physician (usually a nephrologist) begins by taking a detailed clinical history and

performs a physical examination.

In addition to medical history and presenting symptoms,

a physician will ask about medication history, family history recent infections,

toxic/chemical exposures and other historical factors that may indicate an etiology for the

patient's renal disease.

Often, some diseases are suggested by clinical history and time course alone.

For example, in a formerly healthy child with a recent upper respiratory tract infection and

facial/lower limb swelling, findings of proteinuria on urinalysis,

a diagnosis of minimal change disease is highly suggested.

Similarly, a patient with a history of diabetes who presents with decreased urine output is most

likely to be suffering from diabetic nephropathy.

Often, such cases do not require extensive workup (such as with renal biopsy).

A presumptive diagnosis can be made on the basis of history,

physical exam and supportive laboratory studies.

Laboratory [edit]

Laboratory studies are an important adjunct to clinical eval‎uation for assessment of renal

function.

An initial workup of a patient may include a complete blood count (CBC);

serum electrolytes including sodium, potassium, chloride, bicarbonate, calcium, and phosphorus;

blood urea, nitrogen and creatinine;

blood glucose and glycocylated hemoglobin.

Glomerular filtration rate (GFR) can be calculated.^[19]

Urine studies may include urine electrolytes, creatinine, protein, fractional excretion of sodium

(FENA) and other studies to assist in eval‎uation of the etiology of a patient's renal disease.

Urinalysis is used to eval‎uate urine for its pH, protein, glucose,

specific gravity and the presence of blood.

Microscopic analysis can be helpful in the identification of casts, red blood cells,

white blood cells and crystals.^[19]

Imaging [edit]

Imaging studies are important in the eval‎uation of structural renal disease caused by urinary

tract obstruction, renal stones, renal cyst, mass lesions, renal vascular disease,

and vesicoureteral reflux.^[19]

Imaging techniques used most frequently include renal ultrasound and helical CT scan.

Patients with suspected vesicoureteral reflux방광요관역류may undergo voiding

Cystourethrogram 방광요도조영상(VCUG).

Biopsy [edit]

The role of the renal biopsy is to diagnose renal disease in which the etiology is not clear

based upon noninvasive means (clinical history, past medical history, medication history,

physical exam, laboratory studies, imaging studies).

A detailed description of renal biopsy interpretation is beyond the scope of this article.

In general, a renal pathologist will perform a detailed morphological eval‎uation and integrate

the morphologic findings with the clinical history and laboratory data,

ultimately arriving at a pathological diagnosis.

A renal pathologist is a physician who has undergone general training in anatomic pathology

and additional specially training in the interpretation of renal biopsy specimens.

Ideally, multiple core sections are obtained and eval‎uated for adequacy (presence of glomeruli)

intraoperatively.

A pathologist/pathology assistant divides the specimen(s) for submission for light microscopy,

immunofluorescence microscopy and electron microscopy.

The pathologist will examine the specimen using light microscopy with multiple staining

techniques (hematoxylin and eosin/H&E, PAS, trichrome, silver stain) on multiple level sections.

Multiple immunofluorescence stains are performed to eval‎uate for antibody,

protein and complement deposition.

Finally, ultra-structural examination is performed with electron microscopy and may reveal

the presence of electron-dense deposits or other characteristic abnormalities that may suggest

an etiology for the patient's renal disease.

In other animals [edit]

A pig's kidney opened.

In the majority of vertebrates, the mesonephros persists into the adult, albeit usually fused with

the more advanced metanephros; only in amniotes is the mesonephros restricted to the embryo.

The kidneys of fish and amphibians are typically narrow, elongated organs,

occupying a significant portion of the trunk.

The collecting ducts from each cluster of nephrons usually drain into an archinephric duct,

which is homologous with the vas deferens of amniotes.

However, the situation is not always so simple; in cartilaginous fish and some amphibians,

there is also a shorter duct, similar to the amniote ureter,

which drains the posterior (metanephric) parts of the kidney,

and joins with the archinephric duct at the bladder or cloaca.

Indeed, in many cartilaginous fish, the anterior portion of the kidney may degenerate or

cease to function altogether in the adult.^[20]

In the most primitive vertebrates, the hagfish and lampreys, the kidney is unusually simple:

it consists of a row of nephrons, each emptying directly into the archinephric duct.

Invertebrates may possess excretory organs that are sometimes referred to as "kidneys", but,

even in Amphioxus,

these are never homologous with the kidneys of vertebrates,

and are more accurately referred to by other names, such as nephridia.^[20]

Juvenile monogenean parasite in the kidney^[21] of the African clawed frog Xenopus laevis

In amphibians, kidneys and the urinary bladder harbour specialized parasites, monogeneans

of the family Polystomatidae.^[21]

The kidneys of reptiles consist of a number of lobules arranged in a broadly linear pattern.

Each lobule contains a single branch of the ureter in its centre,

into which the collecting ducts empty.

Reptiles have relatively few nephrons compared with other amniotes of a similar size,

possibly because of their lower metabolic rate.^[20]

Birds have relatively large, elongated kidneys,

each of which is divided into three or more distinct lobes.

The lobes consists of several small, irregularly arranged, lobules, each centred on a branch

of the ureter.

Birds have small glomeruli, but about twice as many nephrons as similarly sized mammals.^[20]

The human kidney is fairly typical of that of mammals.

Distinctive features of the mammalian kidney, in comparison with that of other vertebrates,

include the presence of the renal pelvis and renal pyramids,

and of a clearly distinguishable cortex and medulla.

The latter feature is due to the presence of elongated loops of Henle;

these are much shorter in birds, and not truly present in other vertebrates

(although the nephron often has a short intermediate segment between the convoluted tubules).

It is only in mammals that the kidney takes on its classical "kidney" shape,

although there are some exceptions, such as the multilobed reniculate kidneys of cetaceans.^[20]

Evolutionary adaptation [edit]

Kidneys of various animals show evidence of evolutionary adaptation and have long been

studied in ecophysiology and comparative physiology.

Kidney morphology, often indexed as the relative medullary thickness,

is associated with habitat aridity among species of mammals,^[22]

and diet (e.g., carnivores have only long loops of Henle).^[14]

Society and culture [edit]

Kidneys as food[edit]

Hökarpanna, Swedish pork and kidney stew

The kidneys like other offal , (새·짐승의) 내장 , can be cooked and eaten.

Kidneys are usually grilled or sautéed, but in more complex dishes they are stewed with a sauce

that will improve their flavor.

In many preparations, kidneys are combined with pieces of meat or liver,

as in mixed grill or meurav Yerushalmi.

Dishes include the British steak and kidney pie, the Swedish hökarpanna (pork and kidney stew),

the French rognons de veau sauce moutarde (veal kidneys in mustard sauce)

and the Spanish riñones al Jerez (kidneys stewed in sherry sauce) .^[23]

History [edit]

The Latin term renes is related to the English word "reins", a synonym for the kidneys in

Shakespearean English (e.g. Merry Wives of Windsor 3.5), which was also the time when

the King James Version of the Bible was translated.

Kidneys were once popularly regarded as the seat of the conscience and reflection,^[24][25]

and a number of verses in the Bible (e.g. Ps. 7:9, Rev. 2:23) state that God searches out and

inspects the kidneys, or "reins", of humans, together with the heart.

Similarly, the Talmud (Berakhoth 61.a) states that one of the two kidneys counsels what is good,

and the other evil.

According to studies in modern and ancient Hebrew,

various body organs in humans and animals served also an emotional or logical role,

today mostly attributed to the brain and the endocrine system.

The kidney is mentioned in several biblical verses in conjunction with the heart,

much as the bowels were understood to be the "seat" of emotion - grief, joy and pain.^[26]

In the sacrifices offered at the biblical Tabernacle and later on at the temple in Jerusalem,

the priests were instructed ^[27] to remove the kidneys and the adrenal gland covering the kidneys

of the sheep, goat and cattle offerings, and to burn them on the altar,

as the holy part of the "offering for God" never to be eaten.^[28]

In ancient India, according to the Ayurvedic medical systems,

the kidneys were considered the beginning of the excursion channels system,

the 'head' of the Mutra Srotas, receiving from all other systems, and therefore important in

determining a person's health balance and temperament by the balance and mixture of the

three 'Dosha's - the three health elements: Vatha (or Vata) - air, Pitta - bile, and Kapha - mucus.

The temperament and health of a person can then be seen in the resulting color of the urine.^[29]

Modern Ayurveda practitioners, a practice which is characterized as pseudoscience,^[30]

have attempted to revive these methods in medical procedures as part of Ayurveda

Urine therapy.^[31]

These procedures have been called "nonsensical" by skeptics.^[32]

In ancient Egypt, the kidneys, like the heart, were left inside the mummified bodies,

unlike other organs which were removed.

Comparing this to the biblical statements, and to drawings of human body with the heart and two

kidneys portraying a set of scales for weighing justice, it seems that the Egyptian beliefs had also

connected the kidneys with judgement and perhaps with moral decisions.^[33]

See also[edit]

• Artificial kidney

• Holonephros

• Organ donation

• Organ harvesting

• Pelvic kidney

• World Kidney Day

References [edit]