Transcript The Skin - My CCSD

By:
Tyler Halbett
Karina Lopez
Yanelli Salinas
Major Functions
 Regulates blood volume and blood pressure.
 Regulates plasma concentrations of ions.
 Helps to stabilize blood pH.
 Conserves valuable nutrients.
 Cool the body and regulate the salt content.
The Major Organs
 The major organs in the Excretory System include:
 The Kidneys.

The Lungs.

The Skin.

The Urinary Bladder.

The Liver.
LUNGS
SKIN
LIVER
KIDNEYS
URINARY
BLADDER
URETERS
URETHRA
The Kidneys
Renal
Medulla
Renal Capsule
Renal
Pyramid
Renal
Sinus
Renal Cortex
Hilum
Major
Calyx
Ureter
Minor Calyx
Renal Column
The Kidneys
 Main structures of the kidneys:
 The hilum is the site of exit for the ureter and the renal vein. It
is also the site of entrance for the renal artery and nerve.
 The renal capsule is the outer layer of the kidney which
protects the kidney’s inner structures.
 The inner portion of the kidney is divided into three major
areas: the outer renal cortex, the middle renal medulla, and the
inner renal pelvis.
 There are 6-18 renal pyramids in each renal medulla.
 The ends of each renal medulla are called renal papilla, which
is where urine is first stored before exiting the kidney.
The Kidneys
 Main structures of the kidneys:
 Each renal papilla extends into a minor calyx.
 Four or five minor calyces merge to form one major calyx,
which extends into the renal sinus.
 The renal sinus is where urine is stored before it goes out the
hilum.
 The renal columns separate the renal medullae.
 The nephron is a microscopic tube-like structure where urine
production begins.
The Kidneys
 Location:
 The kidneys are located on either side of the vertebral column,
between the 12 Thoracic vertebra and the 3 Lumbar vertebra.
 The kidneys sit inferior to the adrenal glands.
 The left kidney is located superior to the right kidney.
The Kidneys
 Functions:
 The kidney are responsible for urine production.
 The kidneys clean the blood of impurities, producing urine in
the process.
 Maintain homeostasis.
 The production of Antidiuretic Hormone (ADH) in order to
reabsorb water (when plasma osmolality either rises or falls).
 The regulation of blood pressure in the long run.
 The secretion of hormones, including: erythropoiesis (the
production of red blood cells), calcitriol (intestinal absorption
of calcium), and renin (mediates the extracellular volume).
The Kidneys
 Blood is brought into the kidneys by way of the renal
arteries that pass through the hilum of the kidneys.
 The renal artery branches into several interlobar
arteries that extend up and through the renal
columns and renal capsule.
 The blood goes through filtration (where urine is
separated from the blood and other impurities
cleaned out from the blood) and is passed into the
interlobar veins that exit the kidneys.
 Despite their size, the kidneys receive 20% of the
cardiac output.
The Ureters
The Ureters
 Muscular ducts
 25-30 cm long (10-12 in!)
 Location:
 The ureters are located inferior to each kidney, superior to the
urinary bladder.
 Function:
 The ureters are responsible for transporting the urine
produced in the kidney to be stored in the urinary bladder.
The Urinary Bladder
The Urinary Bladder
 A hollow muscular organ that collects urine
produced by the kidneys and deposited by the
ureters before exiting the body.
 Along with the ureters and urethra, the urinary
bladder contains transitional epithelial cells – the
type of cell that can expand to hold more fluid
(urine).
 The bladder can hold up to 11.9 liters of fluid.
The Urinary Bladder
 Location:
 The urinary bladder is located within the pelvic sinus, inferior
to the ureter.
 Function:
 The main function of the urinary bladder is to hold the urine
produced by the kidneys before it exits the body.
 In pregnant woman, the uterus expands into the
urinary bladder, resulting in the bladder being able
to hold less urine, and causing women to urinate
more often.
The Urethra
The Urethra
 Hollow, muscular tubular structure.
 In males, it averages between 18-20 cm, and in
females, it averages between 3-5 cm.
 Location:

The urethra is located inferior to the urinary bladder, and
leads to the exterior of the body.
 Function:
 The urethra’s main function is the transport of urine outside of
the body.
The Micturition Reflex
 The process of urination if coordinated by this reflex.
It includes several steps:
1.
2.
3.
4.
Stretch receptors in the urinary bladder are stimulated as the
bladder fills with urine. The afferent fibers in the pelvic
nerves carry impulses to the spinal cord.
This impulse is sent to the thalamus on its way to the cerebral
cortex.
Once the impulse reaches the cerebral cortex, you become
aware of the fluid pressure in the bladder.
The urge to urinate appears when the bladder contains about
200 mL of urine.
The Micturition Reflex
1.
2.
Action potential carried by efferent fibers in the pelvic nerves
stimulate ganglionic neurons in the bladder wall. These
neurons then stimulate sustained contraction of the detrusor
muscle.
This contraction elevates fluid pressures in the bladder.
However, urine ejection does not happen unless both the
internal and external urethral sphincters are relaxed. The
external urethral sphincter is relaxed voluntarily, and as
such, so is the interior urethral sphincter.
The Micturition Reflex
The Lungs
The Lungs
 The lungs are responsible for separating oxygen from
the air we inhale, and give this oxygen to the blood so
that it may be transported around the body. The
excess air is then exhaled back out the same way
(nasal cavities – pharynx – trachea – lungs, and vice
versa).
 Inhaled air is composed of a variety of natural
airborne gases, of which contains oxygen that is
needed to sustain life. The lungs separate this oxygen
and exhale the remainder of the air.
The Liver
The Liver
 The liver converts ammonia into urea, a main
component during urine production. It helps
reabsorb water in the kidneys, where some of it will
be lost into the urine.
 The liver produces bile, a main acid stored by the gall
bladder. It is responsible for helping to digest food
within the stomach. This digested food is then forced
through the remainder of the digestive system and
ultimately, out of the body.
The Skin
The Skin
 The skin contains millions of tiny glands known as
sweat glands, which are the primary way of excreting
excess water from within the body to the surface of
the skin (for a variety of functions).
 Sebaceous glands are also found within the skin, and
are responsible for excreting sebum, or body oil onto
the surface of the skin.
 The sweat and sebum are responsible for keeping
skin the way it is.
Diseases of the Excretory System
Hydronephrosis: An
enlargement of one
or both of the
kidneys due to an
obstruction within
the flow of urine.
Urinary Tract
Infection: When
bacteria manages
to get into the
urine, it causes
UTI; can lead to a
kidney or bladder
infection.
Nephrotic
Syndrome: A kidney
becomes damaged,
causing a loss in
protein from the
blood to the urine. It
can lead to
Heamturia, where
red blood cells get
mixed into the
urine.
Diseases of the Excretory System
Hepatitis:
Includes many
of the same
symptoms as
the flu, but
causes bodily
pain and a
discoloration of
feces and urine.
Alcoholism:
Due to
drinking too
much alcohol,
the liver begins
to degrade and
not function as
well, as well as
not being able
to regenerate
itself.
Cancer: Cells divide
at an uncontrollable
rate, invade other
regions, and
sometimes perform
metastasis (invasion
of other bodily areas
through lymph or
blood).
Integration With Other Systems
 Respiratory:
 The lungs inhale vital oxygen needed to sustain life, and exhale
the excess air (carbon dioxide, nitrogen, etc.).
 Integumentary:
 The sweat glands found in the skin are responsible for carrying
excess water within the body onto the surface of the skin (for a
variety of functions).
 Digestive:
 The liver produces bile that helps in digesting food within the
stomach.
Fun Facts
 You can survive with
only one kidney.
 Even if up to 75% of the
liver is destroyed, the
remaining amount will
regenerate the missing
portion.
•The average human
inhales roughly 11,000
liters of air a day, but only
550 liters of it is pure
oxygen.
•A majority of kidney
stones pass through the
urinary system without
incident. Many do not
cause any problems.