The Urinary SystemThe Urinary System

Components of Urinary SystemComponents of Urinary System

2 Kidneys (major organs)

2 Ureters (Passage tubes ?)

Bladder (Storage)

Urethra (excretion)

The KidneyThe Kidney(Shape & Location)(Shape & Location)

Bean shaped organ

Location:

Post. Abdominal wall, retroperitoneal (?)

At vertebral level of ??-??

Protected by 11th & 12th ribs

Rt. Kidney is slightly lower than lf. (why?)

External Anatomy of KidneyExternal Anatomy of Kidney

Convex lat. border

Concave medial border,

Contains in its middle the

renal hilum

Renal Hilum:

The area where str. Enter or leave the kidney (root of the kidney)

Structures within The HilumStructures within The Hilum

From ant. to post.:

Renal Vein:

most ant.

Lf. is longer than Rt.

Renal Artery

Ureter:

most posterior

Internal Anatomy of The KidneyInternal Anatomy of The KidneyIn longitudinal section

Outer layer = cortex(divided into 2 zones ?)

Inner renal pyramids = medulla (~8-18)

Renal columns:??

The kidney is protected by D.Ir.C.T. capsule = Renal Capsule

Draining System Within KidneyDraining System Within Kidney

Each pyramid contains many collecting ducts

Gathered to form the

renal papilla

(Apex of the pyramid)

Minor Calyx

(Calyx = cup)

Draining System Within KidneyDraining System Within Kidney

Each pyramid drains into

Minor calyx

(how many?)

Minor calyces join into

Major calyx

(~2-3)

Major calyces join into

Renal pelvis

Renal pelvis drains to

ureter

Arterial Blood Supply To The KidneyArterial Blood Supply To The Kidney

Renal a.

Segmental a.

(5 a.)

Interlobar a.

pass through ??

Arcuate a.

over the bases of the pyramids

Arching between??

Interlobular

Between lobules of the kidney

““The Nephron”The Nephron”

The functional unit of the kidney that is responsible for bld. filtration & urine production

Each kidney contains ~1 million nephrons (constant #)

Consists of:

1. Renal corpuscle

2. Renal tubules

Renal CorpuscleRenal Corpuscle

Corpuscle = tiny body

Located in ??

Fx.: bld. filtration &

urine formation

Composed of:

1. Glomerulus:

Capillary network

2. Glomerular (Bowman’s) capsule

Double walled cup (simple sq. epith.)

One side: surround the capillaries (Visceral)

Other side: continues with tubules (parietal)

Renal CorpuscleRenal Corpuscle

??????

??

Renal TubulesRenal Tubules

PCT

Cortex

Simple cub. epith.

Loop of Henle

Cortex & Medulla

Simple sq. epth.

2 limbs: ?

DCT

Cortex

Simple cub. epith.

Drain into ??

Convoluted: tightly coiled

Collecting & Papillary DuctsCollecting & Papillary Ducts

Collecting Ducts:

Larger tubules that receive the DCT of several nephrons

* Each collecting duct & group of nephrons draining into it

Renal Lobule

Papillary ducts: (see previous slide)

Large ducts that result from union of collecting ducts

Located at the apex of renal pyramids (renal papilla)

Several hundreds in #

Drain into ??

Review:Review:

1. Nephron: fxnal unit

Renal corpuscle

- ?

- ?

Renal tubules

- ?

- ?

- ?

2. Collecting ducts

cortex & medulla

3. Papillary ducts:

renal papilla

Renal TransplantRenal TransplantTransfer of a kidney from a living donor or cadaver to a pt. with

renal failure

1- Donor kidney usually placed in

the pt. pelvis

2- Renal a. & v. : attached to iliac a. & v.

3- Ureter: attached to bladder

4- Diseased kidneys: left in place

5- Pt. receives immunosuppressive drugs for life (why?)

HemodialysisHemodialysis

An artificial method for bld. Filtration when kidneys are in renal failure

Dialysis Solution

Selective permeable membrane

CAP Dialysis ?CAP Dialysis ?

Artificial kidney machine

UreterUreter

Narrow muscular tube that transports urine from the ?? to the ??

( 25 cm)

Transportation Mechanisms:

1. Peristaltic contractions:

smooth m. on the wall

1 - 5/min

2. Gravity

Opens obliquely into the post. Aspect of the bladder (Physiological sphincter)

UreterUreter

3 areas of constriction:

When renal pelvis joins the ureter

Over pelvic brim

When enters the bladder (posteriorly)

Urinary BladderUrinary Bladder

Hallow distensible muscular organ located in the pelvis, post. To pubic symphysis

Shape: varies (depending on urine content)

empty: collapsed

normal fill: spherical

overfilled: pear-shaped

Average capacity ~700-800ml

( females ??)

Internal AnatomyInternal AnatomyRugae & Trigone

Rugae: folds of bladder mucosa

- more prominent when bladder is ??

Trigone: small triang. Area in the floor of the bladder

- No rugae (smooth)

- Very sensitive to expansion

- Post. Corners= openings of ?, ant. Corner: opening of ?

UrethraUrethra

Small tube that responsible for urine excretion from the bladder

Male:

longer (~20cm)

3 parts:

Prostatic, membranous & penile

Female:

Shorter (~4cm)