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Biology 211 Anatomy _amp; Physiology I

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Biology 211 Anatomy _amp; Physiology I Powered By Docstoc
					  Biology 322
Human Anatomy I

Renal System
Organs of Renal System
Kidney
Located high in abdominal cavity
Posterior to peritoneum



Liver pushes right kidney
  more inferiorly
Mass ~
Size ~
Kidney

            : External covering
of dense irregular connective
tissue

          Outer solid region

              Inner solid region
 8 to 12 cone-shaped masses
  (apex toward hilus) called renal       ,
  separated by renal            .

         Hollow medial region, extensions = calyces
  Connects medially with ureter
Kidney:
                 Each renal artery (direct
                 branch of aorta) divides into
                 lobar (segmental) arteries,
                 which divide into interlobar
                 arteries, then arcuate
                 arteries (between cortex &
                 medulla), which give off
                 interlobular arteries into
                 both cortex & medulla.

          You learned these as part
          of the renal lab exercise.
          Be sure you also know
          them for lecture exams
In cortex, interlobular
arteries send blood
through afferent arterioles
into groups of capillaries
called glomeruli.
This is where filtration will
occur to begin formation of
urine


From a glomerulus, blood flows out an efferent arteriole to
another set of capillaries called peritubular capillaries
which surround the tubules where urine is forming.
Each renal artery divides
into lobar arteries,
     interlobar arteries,
     arcuate arteries,
     interlobular arteries,
     afferent arterioles,
     glomeruli,
     efferent arterioles,
     peritubular capillaries

Blood then flows into
interlobular veins or
arcuate veins,
interlobar veins, and
lobar veins to reach the
renal vein which carries it to
the inferior vena cava.
Let’s go back to the glomerulus:

                              Consists of a group of
                              interconnected capillaries.
                              As blood flows through these
                              capillaries, plasma (the liquid
                              part of blood) is filtered out
                              and flows though a series of
                              tubes to form urine.

                              This series of tubes is called
                              a nephron.
Structure of Glomerulus




Capillary wall (simple squamous epithelium, fenestrated)
           plus podocytes
           plus basement membrane between them
form the filtration membrane across which liquid is filtered
from the blood to the glomerular capsule.
 Each kidney contains ~ 1,000,000 nephrons
 Pattern of nephrons creates pattern of cortex and medulla:




Cortex consists primarily of convoluted tubules which twist
many directions.
Medulla consists primarily of loops of Henle & collecting ducts
all oriented in the same direction
This fluid filtered out of the blood flows into the proximal
convoluted tubule, through other parts of nephron, into
collecting duct.


                                           Recall that nephron
                                           is surrounded by
                                           peritubular capillaries
                                           for resabsorption of
                                           water and solutes
Urine passes from a
collecting duct into a
minor calyx, then a
major calyx, then
the pelvis of the
kidney.
Urine leaving the pelvis
enters the ureter, which
carries it to the
urinary bladder.
Ureters: Retroperitoneal.

Anterior to common iliac
arteries & veins.




Deliver urine to
posterolateral parts of
urinary bladder.
Ureter:




Mucosa: Transitional epithelium
        Lamina Propria (loose C.T.)

Muscularis: Thick wall of smooth muscle

Adventitia:   Dense irregular C.T.
Urinary Bladder:

In pelvis, posterior to pubic
bone
Superior surface covered
by peritoneum

Female:
Anterior to uterus/vagina

Male:
Anterior to rectum
Superior to prostate
Urinary Bladder:

             Mucosa: Transitional epithelium
                     Lamina propria

                      Muscularis: Thick smooth muscle
                                  (“detrusor”)


                                  Adventitia (C.T.) covers
                                           most of bladder
                                  Serosa on its superior
                                          surface
Urinary Bladder:
Urinary Bladder:
Urinary Bladder:

                                       Muscularis
                                       (detrusor muscle)
                                         and
                                       Internal Urethral
                                       Sphinter both
                                        smooth muscle;
                                        thus involuntary




Urine leaving bladder enters urethra
Urethra:




Adventitia:   Dense irregular C.T.

Muscularis: Thick wall of smooth muscle

Mucosa: Epithelium varies from transitional near bladder
           to stratified squamous at end
         Male urethra much longer, has middle region of
           stratified columnar. Female urethra does not.
        Lamina Propria (loose C.T.)
External
Urethral
Sphincter
            External
            Urethral
            Meatus
Tonight:
On yourself or another person, locate kidneys
                                      ureters
                                      bladder
                                      urethra

				
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