The kidney plays an important endocrine role by secreting several hormones. The document discusses four key hormones secreted by the kidney: erythropoietin, calcitriol, thrombopoietin, and renin. Erythropoietin stimulates red blood cell production. Calcitriol helps absorb calcium. Thrombopoietin stimulates platelet production. Renin regulates blood pressure through the renin-angiotensin system. The kidneys secrete these hormones through specialized cells like the juxtaglomerular cells and extraglomerular mesangial cells to perform critical functions in the body.

1. ENDOCRINE FUNCTION OF
KIDNEY
BY :
KHAZI ABDUL JABBAR,
GROUP NO.117,
UNDER SUPERVISION OF Dr. G.N.Yegorov.

2. ENDOCRINE SYSTEM

3. KIDNEY A MIXED ORGAN

4. HORMONES
 THERE ARE THREE TYPES OF HORMONES:
 steroid
hormones including prostaglandins which
function especially in a variety of female
functions and the sex hormones all of which are
lipids made from cholesterol,
 amino acid derivatives (like epinephrine) which
are derived from amino acids, especially
tyrosine, and
 peptide hormones (like insulin) which is the
most numerous/diverse group of hormones.

5. CELLS THAT SECRETES HORMONES:
 The juxtaglomerular cells (JG cells or granular cells) are cells in
the kidney that synthesize, store, and secrete the enzyme renin.
They are specialized smooth in the wall of the afferent arterioles
that delivers blood to the glomerulus. In synthesizing renin, they
play a critical role in the renin-angiotensin system and thus in renal
auto regulation, the self-governance of the kidney.

6. Extraglomerular mesangial cells(also known asLacis cells,Goormaghtigh cells)
are light-staining cells in thekidneyfound outside theglomerulus, near
thevascular poleandmacula densa.Lacis cells form thejuxtaglomerular
apparatusin combination with two other types of cells: themacula densaof
thedistal convoluted tubuleandjuxtaglomerular cellsof theafferent arteriole.This
apparatus controlsblood pressure through theRenin Angiotensin Aldosterone
system.The specific function of Lacis cells is not well understood, although it has
been associated with the secretion oferythropoietin.

7. RENAL CORPUSCLE:



A – Renal corpuscle
B – Proximal tubule
C – Distal convoluted tubule
D – Juxtaglomerular apparatus
1. Basement membrane (Basal lamina)
2. Bowman's capsule – parietal layer
3. Bowman's capsule – visceral layer
3a. Pedicels
3b. Podocyte
4. Bowman's space (urinary space)
5a. Mesangium – Intraglomerular cell
5b. Mesangium – Extraglomerular cell
6. Granular cells (Juxtaglomerular cells)
7. Macula densa
8. Myocytes (smooth muscle)
9. Afferent arteriole
10. Glomerulus Capillaries
11. Efferent arteriole

8. HORMONES SECRETED BY KIDNEYS:
Secreted hormone
Secreted hormone
Erythropoietin
Erythropoietin
Calcitriol (1,25dihydroxyvitamin D3
From cells
From cells
Extraglomerular
mesangial cells
Extraglomerular mesangial
cells
Calcitriol (1,25dihydroxyvitamin D3)
Renin (Primarily)
Renin (Primarily)
Thrombopoietin
Juxtaglomerular cells
Juxtaglomerular cells
Effect
Stimulate erythrocyte pro
duction
Stimulate erythrocyte pr
Active form
oduction of vitamin D3
Increase absorption
of calcium and phosphate
from gastrointestinal tract
Active form of vitamin
D3
Increase absorption
Activates and phosphat
of calciumthe reninangiotensin system by
e from gastrointestinal
producing angiotensin
tract
I of angiotensinogen
Activates the reninangiotensin system by
stimulates megakaryocyt
producing angiotensin
Ies to produce platelets
of angiotensinogen

9. Erythropoietin
 Erythropoietin
 Erythropoietin, or EPO, is a glycoprotein that
regulates the transfer of oxygen and nutrients
through the bloodstream by increasing red blood
cell production in the bone marrow. EPO
production is stimulated when blood is lost
through a wound or when less oxygen is
available, such as higher altitudes. Recombinant
EPO can be used as a treatment for those
suffering from anemia, a deficiency of red blood
cells.

10. Calcitriol
 Calcitriol
 Calcitriol, also known as vitamin D3, improves the
body's ability to absorb calcium. To produce
calcitriol, vitamin D must be introduced into the
body, either through a chemical reaction between
the skin and sunlight creating calciferol, or dietary
vitamin D that has been digested. Vitamin D in the
body ends up being converted into calcitriol by the
kidneys. Calcitriol travels to the intestines, where it
enhances the body's absorption of calcium,
improving skeletal health.


11. Thrombopoietin
 Thrombopoietin
 Thrombopoietin, or TPO, increases the body's ability
to heal itself by stimulating the production of
platelets. Thrombopoietin is a cytokine, a protein
involved with immune system functioning. TPO that
has been secreted into the bloodstream bonds either
with platelets or with megakaryocytes, the precursor
to platelets. When the body's platelet count is high,
excess TPO bonds with the platelets, decreasing
production. If the platelet count is low, TPO bonds
with megakaryocytes which then mature into
platelets.

12. Rennin
 Rennin
 Rennin is a proteolytic enzyme responsible for
regulating arterial wall size to ensure proper blood
pressure. Proteolytic enzymes are capable of
breaking down proteins into a more usable form.
Renin breaks down the plasma protein
angiotensinogen into a peptide containing ten
amino acids called angiotensin I. Angiotensin I later
gets broken down by a lung-based peptidase known
as angiotensin converting enzyme, or ACE. The new
eight-amino acid peptide, angiotensin II, increases
blood pressure by increasing pulse strength and
constricting vein and arterial walls.

14. THANK ‘Q