part of dr . hanaa

1. Principles of physiology
 Nutrition, Digestion & Metabolism
 Blood
 Respiration
 Excretion
 Muscular system
 Nervous system
 Endocrine system

2. EXCRETION

3. LUNG
 Excrete carbon
dioxide and water
The wastes of cellular
respiration

4.  Removes
toxic substances
from the blood
 Converts
hemoglobin from
old RBC’s to bile
pigments
eliminated in the
feces
LIVER

5.  Disposal of nitrogenous wastes
 Breaks down excess
amino acids (deamination)
 Amino group ammonia urea
Urea transported to the kidneys by the blood

6. Skin
 sweat
glands
excreto
structur
of the s

7. URINARY SYSTEM
 kidneys,
 ureters,
 urinary
bladder
 urethra

8. URINARY SYSTEM
kidneys (2) are bean
shaped organs ,
10 cm long ,
located below the
diaphragm near
the back

9. 3 main functions:
1. Excretion(remove wastes of cellular
metabolism from the blood)
2. Regulation, homeostasis
(concentrations of substances found in
body fluids,plasma,pH, blood pressure)
3. Secretion (rennin, and erythropoietin)

12. Kidney Structure
 Kidneys consist of
microscopic
structures called
 NEPHRONS.

13. A NEPHRON
Made of :
1- Glomerulus: a network of
capillaries
2- Bowman’s
capsule:
cup-like structuresurrounding the
glomerulus
3- Renal tubule

14.  Proximal convoluted
tubule (PCT)
 longest, most coiled,
simple cuboidal with
brush border
 Nephron loop - U
shaped; descending +
ascending limbs
 Distal convoluted tubule
(DCT)
 cuboidal, minimal
microvilli

15. Juxta-glomerular apparatus:
 A group of spindle shaped cells in the media
of afferent glomerular arterioles
 -Secrete rennin ( increase renal blood flow ).
 -Secrete erythropoietine, a hormonal agent
necessary for production of red blood cells
by bone marrow.
 -Secrete chemical factor ,regulate the output
of aldosterone.

16. A nephron works in 3 stages:
 1- Filtrations stage: water, minerals,
salts, urea, amino acids and glucose are
filtered out of the blood

17. Filterate
170-180L/day
resemble blood plasma (except RBCs,plasma
protein
3 forces :
 High glomerular capillaries pressure
 High glomerular osmotic pressure
 Low filterate pressure

18.  2- Reabsorption
stage:
 water, minerals,
amino acids and
glucose are
reabsorbed by
active transport
from the renal
tubule into the
capillaries
 3- Secretion stage

21. Urine Formation Preview

22. Urine Volume
 Normal volume - 1 to 2 L/day
 Polyuria > 2 L/day
 Oliguria < 500 mL/day
 Anuria - 0 to 100 mL

23. DiabetesChronic polyuria
 With hyperglycemia and glycosuria
 diabetes mellitus I and II, insulin
hyposecretion/insensitivity
 gestational diabetes, 1 to 3% of pregnancies
 pituitary diabetes, hypersecretion of GH
 adrenal diabetes, hypersecretion of cortisol
 With glycosuria but no hyperglycemia
 renal diabetes, hereditary deficiency of glucose
transporters
 With no hyperglycemia or glycosuria
 diabetes insipidus, ADH hyposecretion

24. URETERS
 Tubes
carry urine
from the
kidney to the
bladder

25. URINARY BLADDER
 Stores urine

26. URETHRA
 Tube that
carries urine
from the
bladder to the
outside of the
body

27. Function - Homeostasis
 Acid-Base Balance
 Kidneys regulate the pH, mineral ion concentration,
and water composition of the blood.
 By exchanging hydronium ions and hydroxyl ions,
the blood plasma is maintained by the kidney at pH
7.4.
 Urine, becomes either acidic at pH 5 or alkaline at
pH 8.
 Water Balance
 Aldosterone
 Plasma Volume
 ADH

28. Aldosterone
 A steroid hormone (m alocorticoid)
 It is formed in the outer-section (zona
glomerulosa) of the adrenal cortex
 It diminishes the excretion of Na+ ions and
therefore water, and stimulates the excretion
of K+ ions by the kidneys.

29. ADH (VASOPRESSIN)
 when the body is low on water.
kidneys conserve water
 osmotic activity increase
con. urine.
 → stimulate OSMOTIC RECEPTORS in the
hypothalamus
 → stimulation of posterior pituitary lobe


→ activation of VASOPRESSIN
→ increase collecting ducts permeability for water
 → reabsorption
 →HYPERTONIC URINE

30. Malfunctions
Kidney Diseases:
 Various conditions in which the
kidneys are unable to properly
excrete nitrogenous wastes

31. Kidney stones:
 Substances crystalize out of the urine
in the urinary tract or in the kidney
 Some pass out in the urine on their
own
 Some can be shattered with lasers or
sound waves
 Some are surgically removed

32.  Dialysis - can
some times be used
to treat various
kidney diseases
 Kidney
transplants