Download excretory system

The Urinary System
Learning Objectives :
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Membuat peta konsep sistem ekskresi manusia
Mengidentifikasi komponen yang terlibat dalam
sistem ekskresi manusia
Menggambar struktur ginjal
Menjelaskan proses pembentukan urine
Membedah serangga untuk diamati struktur alat
ekskresinya
Menggambar struktur alat ekskresi serangga
berdasarkan hasil pengamatan
Learning Objectives :
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To make a concept map of excretory system in
human
To identify components are involved in human
excretory system
To draw kidney structure
To explain the formation of urine
To operate insect for observation its excretory
organs structure
To draw structure of excretory organs based on
observation result
Function
1. Remove nitrogenous wastes
2. Maintain electrolyte, acid-base,
and fluid balance of blood
3. Homeostatic organ
4. Acts as blood filter
5. Release hormones: calcitriol &
erythropoietin
Kidneys as Filters
• Diuretic- loose water; coffee, alcohol
• Antidiuretic- retain water; ADH
• Aldosterone- sodium & water reabsorption,
and K+ excretion
• GFR= 180 liters (50 gal) of blood/day
• 178-179 liters are reabsorbed back into
blood
• Excrete a protein free filtrate
Maintaining
Chemical
Homeostasis
The
Urinary
System
The Urinary System
blood
filtration
General
Functioning
of the Kidney
tubular
reabsorption
and secretion
urine “refreshed” blood
Nitrogenous
Wastes
urea
uric acid
ammonia
kidneys
Organs
of the
Urinary
System
ureters
urinary
bladder
urethra
Human Kidney
Kidney
Anatomy
renal
pelvis
ureter
renal
pyramids
renal
cortex
renal
capsule
renal
medulla
nephron
renal artery
renal vein
Kidney
Anatomy
blood
Nephron
Functioning
filtration
tubular
reabsorption
and secretion
urine “refreshed” blood
efferent
arteriole
afferent
arteriole
glomerulus
artery
peritubular
capillaries
loop of
Henle
vein
Bowman’s
capsule
proximal
convoluted
tubule
distal
convoluted
tubule
collecting
duct
Each kidney contains over 1 million nephrons and thousands
of collecting ducts
Glomerulus
DCT
renal
cortex
PCT
renal
medulla
Collecting duct
Loop of Henle
efferent
arteriole
afferent
arteriole
Glomerular
Filtration
Bowman’s
capsule
Filters blood; proteins can’t pass through
glomerulus
The Human Kidney & Nephron
How urine produced ??
Composition of
Glomerular Filtrate
• Water
• Small Soluble Organic
Molecules
• Mineral Ions
Proximal Convoluted
Tubule
Reabsorbs: water, glucose,
amino acids, and sodium.
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65% of Na+ is reabsorbed
65% of H2O is reabsorbed
90% of filtered bicarbonate (HCO3-)
50% of Cl- and K+
Loop of Henle
Creates a gradient of increasing
sodium ion concentration towards
the end of the loop within the
interstitial fluid of the renal pyramid.
• 25% Na+ is reabsorbed in the loop
• 15% water is reabsorbed in the loop
• 40% K is reabsorbed in the loop
Distal Convoluted
Tubule
Under the influence of the hormone
aldosterone, reabsorbs sodium and
secretes potassium. Also regulates
pH by secreting hydrogen ion when
pH of the plasma is low.
• only 10% of the filtered NaCl and 20% of water
remains
Collecting Duct
Allows for the osmotic
reabsorption of water.
ADH (antidiuretic hormone)- makes
collecting ducts more permeable to
water-- produce concentrated urine
Urine
Water- 95%
Nitrogenous waste:
• urea
• uric acid
• creatinine
Ions:
• sodium
• potassium
• sulfate
• phosphate
From the original 1800 g NaCl, only 10 g appears in
the urine
How
the
kidney
does
its
job!
 Kidney Action
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Blood enters Bowman’s capsule through a tiny
artery — (the renal artery).
The artery branches to form a glomerulus.
Blood pressure forces some blood plasma and
small particles into the surrounding capsule —
(this is called the nephric filtrate).
Large particles such as blood cells and proteins
remain in capillaries.
The nephric filtrate is pushed out of the capsule
and into the proximal tubule .
This is where reabsorption begins.
Kidney action (cont)
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Only materials needed by the body are
returned to bloodstream — for example,
99 % of water, all glucose and amino acids
and many salts are reabsorbed.
Osmosis , diffusion, and active transport
draw water , glucose , amino acids and
ions from filtrate into surrounding cells.
Small villi like projections help in the active
transport of glucose out of the filtrate and
speed up the reabsorption process.
From here, these components return to
the bloodstream.
Kidney action (cont)
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The filtrate reaches the end of the
proximal tubule and the fluid is isotonic
with the surrounding cells.
Glucose and amino acids have been
removed from the filtrate.
The filtrate then moves to the loop of
Henle whose primary function is to
remove water from the filtrate by osmosis.
Kidney action (cont)
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There is in increase in sodium
concentration in the cells of the loop of
Henle as we move from the area of the
cortex to the inner pelvis of the kidney.
This causes water to be drawn from the
filtrate.
These high levels of sodium are a result of
active transport and results in increased
concentration of filtrate (due to water loss).
Why doesn’t water on outside go
back in?
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The water that left the descending loop
cannot enter the ascending loop because
it is impermeable to water.
As the water concentration in the filtrate
decreases, the chlorine concentration
increases and causes it to diffuse out of
the tubule.
This process is helped by the electrical
attraction of chlorine to sodium. .
Water (cont)
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The filtrate moves to the distal tubule
where tubular secretion occurs.
Active transport is used to pull hydrogen
ions, creatinine, drugs such as penicillin
out of the blood and into the filtrate.
Fluid from a number of nephrons moves
from the distal tubules to a common
collecting duct which carries what can
now be called urine to the renal pelvis.
NOTE
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Since the kidneys control what leaves
and what remains in the nephrons, they
maintain the levels of water, ions and
other materials nearly constant and
within the limits to maintain
homeostasis.
Elaborate
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Exocrine/Endocrine Comparison Research
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Exocrine/Endocrine System BINGO
Hormonal
Control of
Kidney
Function
Hormonal Control
of Kidney Function
high plasma
solute
concentration
low blood volume
heart receptors
hypothalamus
Hormonal Control
of Kidney Function
hypothalamus
posterior pituitary
antidiuretic hormone
collecting ducts
Hormonal
Control of
Kidney
Function
Hormonal Control
of Kidney Function
reduced blood pressure and
glomerular filtrate
juxtaglomerular apparatus
renin
Hormonal Control
of Kidney Function
angiotensinogen
angiotensin I
angiotensin II
renin
Hormonal Control
of Kidney Function
angiotensin II
adrenal cortex
aldosterone
convoluted tubules
Urinary Bladder
ureters
external
sphincters
internal
sphincters
urethra
Bladder
1. Mucosa (transitional epithelium)
2. Muscular layer (detrusor muscle):
3 layers of smooth muscle
3. Fibrous adventia
Sphincter Muscles on Bladder
Internal urethral sphincter:
• Smooth muscle
• Involuntary control
• More superiorly located
External Urethral sphincter:
• Skeletal muscle
• Voluntary control
• Posteriorly located
Diuresis (Micturition)
When bladder fills with 200 ml of urine,
stretch receptors transmit impulses to
the CNS and produce a reflex
contraction of the bladder (PNS)
When is incontinence normal?
Distension
of the
Urinary
Bladder
Urinalysis
Why do doctors ask for a urine sample?
characteristics:
• smell- ammonia-like
• pH- 4.5-8, ave 6.0
• specific gravity– more than 1.0; ~1.0011.003
• color- affected by what we eat: salty foods,
vitamins
Odor
odor- normal is ammonia-like
diabetes mellitus- smells fruity or
acetone like due to elevated ketone
levels
diabetes insupidus- yucky
asparagus---
pH- range 4.5-8 ave 6.0
vegetarian diet- urine is alkaline
protein rich and wheat dieturine is acidic
Color
Color- pigment is urochrome
Yellow color due to metabolic breakdown of
hemoglobin (by bile or bile pigments)
Beets or rhubarb- might give a urine pink or
smoky color
Vitamins- vitamin C- bright yellow
Infection- cloudy
Specific Gravity
Water: s.g. = 1g/liter;
Urine: s.g. ~ 1.001 to 1.030
Pyelonephritus- urine has high s.g.;
form kidney stones
Diabetes insipidus- urine has low
s.g.; drinks excessive water; injury or
tumor in pituitary
Abnormal Constitutes of Urine
Glucose- when present in urine condition
called glycosuria (nonpathological)
[glucose not normally found in urine]
Indicative of:
• Excessive carbohydrate intake
• Stress
• Diabetes mellitus
Abnormal Constitutes of Urine
Albumin-abnormal in urine; it’s a very large
molecule, too large to pass through glomerular
membrane > abnormal increase in permeability
of membrane
Albuminuria- nonpathological conditionsexcessive exertion, pregnancy, overabundant
protein intake-- leads to physiologic albuminuria
Pathological condition- kidney trauma due to
blows, heavy metals, bacterial toxin
Abnormal Constitutes of Urine
Ketone bodies- normal in urine but in small amts
Ketonuria- find during starvation, using fat stores
Ketonuria is couples w/a finding of glycosuria-- which
is usually diagnosed as diabetes mellitus
RBC-hematuria
HemoglobinHemoglobinuria- due to fragmentation or hemolysis of
RBC; conditions: hemolytic anemia, transfusion
reaction, burns or renal disease
Abnormal Constitutes of Urine
Bile pigmentsBilirubinuria (bile pigment in urine)- liver pathology such as
hepatitis or cirrhosis
WBCPyuria- urinary tract infection; indicates inflammation of
urinary tract
Casts- hardened cell fragments, cylindrical, flushed out of
urinary tract
WBC casts- pyelonephritus
RBC casts- glomerulonephritus
Fatty casts- renal damage
Summary so far…..
Blood enters the kidney
through the renal artery at
the site of the hilum
The PCT is concerned with
reabsorption- organic nutrients are
reabsorbed and water follows
because there is a concentration
gradient
The remaining filtrate moves
into the descending loop of
henle. This is lined with thin
cells so water moves out
A number of other nephrons join
up to the cleectig duct which
travels through the medulla to the
renal papilla wher the filtrate is
emptied in the minor calyx
4-5 minor calyces join up to
make a major calyx
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The renal artery divides in
to ever smaller arteries and
arterioles
The filtered substances
move into the proximal
convoluted tubule
Because water has been
reabsorbed the concentration
of the filtrate is not very high
From the DCT the filtrate now
passes into the collecting duct.
2-3 major calyces join up
to form the renal pelvis
Afferent arterioles take blood to
the glomerulus to be filtered
Once blood is filtered
efferent arterioles take blood
away from the glomerulus
Products which are filtered out:
water, mineral salts, amino acids,
glucose, hormones, urea, toxins
The glomerulus is a
network of capillaries
which filters the blood
The walls of the ascending loop
of henle are lined with thicker
cells, so water can’t pass in or
out. Instead sodium and
chloride is pumped out actively
In the DCT the volume and
composition of the filtrate
can be adjusted but this is
controlled by hormones
The renal pelvis joins the
ureter at the hilum
Products which do not filter
and remain in the blood:
Leukocytes, erythrocytes,
platelets, plasma proteins
The filtrate now enters the
distal convoluted tubule- is it
now only 20% of what it
originally was.
The ureter transport the
filtrate/urine from the kidney
to the bladder
INQUIRY
1.
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5.
List several functions of the kidneys.
What does the glomerulus do?
What are several constitutes you should not find in urine?
What is specific gravity?
What two hormones effect fluid volume and sodium
concentration in the urine?
6. Where are the pyramids located in the kidney?
7. What vessel directs blood into the glomerulus?
8. Where does most selective reabsorption occur in the
nephron?