Practical 4- Urinary System

kidneys, ureters, urinary bladder, and urethra

The urinary system is composed of the

carbon dioxide, nitrogenous

Cellular processes in the body produce waste products-mainly

wastes, and ammonia.

The urinary system

is the primary system involved in the removal of waste products

electrolyte, acid-base, and fluid balances of

In addition to this vital function, the kidneys also regulate the

blood.

I2th thoracic and 3rd lumbar vertebrae.

The kidneys are bean-shaped retroperitoneal organs located anterior to the ____________________________. They are the principal organs of the urinary system

Renal Fascia

Outer fibrous connective tissue layer that anchors the kidney to the peritoneum and abdominal wall

Adipose Capsule

Fatty middle layer that provides shock absorption

Renal Capsule

Strong fibrous layer that adheres directly to the surface of the kidney and provides protection from spreading infection

Hium (hilus)

Medial concave surface of kidney; location of entrance/exit of ureter and blood vessels

Renal Cortex

Outer region of the kidney; superficial to the medulla

Renal Medulla

Middle region of the kidney; deep to the cortex

Renal Sinus

Inner region of the kidney

Renal Pyramids

Triangular-shaped structures found in the medulla

Renal Papilla

Apex of the renal pyramids that project into the minor calyces; site of the papillary ducts

Renal Columns

Extensions of the renal cortex into the medulla, separating the renal pyramids

Minor Calyces

Structures that receive urine from the renal papilla

Major Calyces

Structures that receive urine from the minor calyces

Renal Pelvis

Structure that receives urine from the major calyces

The ureters, urinary bladder, and urethra

are accessory organs of the urinary system

The ureters, urinary bladder, and urethra

serve to transport, store, and excrete urine

ureters

The _________ are long, narrow retroperitoneal tubes that connect the kidney to the urinary bladder

gravity

Urine passing through the ureters is propelled by peristaltic contractions, hydrostatic pressure, and ________

urinary bladder

The _____________ is a large, hollow muscular organ that serves as a temporary storage sac for urine

transitional epithelium

Specialized epithelial tissue (________________) allows the urinary bladder to change its shape based on the amount of urine it contains

empty

pyramidal shape bladder means

full

Ovoid shape bladder means

urethra

The ______ conveys urine from the urinary bladder to the outside of the body

internal urethral sphincter

A band of smooth muscle (_________________) regulates the passage of urine from the urinary bladder into the internal urethral ori-fice

detrusor muscle

The ____________ __________- of the urinary bladder contracts and forces urine into the urethra during urination

micturition

Urination aka

external urethral sphincter

The _____ _________ __________controls the movement of urine from the urethra to the external urethral orifice

4 cm

The female urethra

15-20 cm

male urethra

Detrusor Muscle

Smooth muscle of the urinary bladder responsible for the expulsion of urine from the urinary bladder during micturition

Trigone

Triangular-shaped region at the base created by the openings of the ureters and urethra forming a smooth funnel

Renal (fibrous) capsule

Fibrous layer that adheres to the kidney surface

Ureter

Tube connecting the kidney to the urinary bladder

Adipose capsule

If present, this is a fatty layer that protects the kidney

Hilum

Medial concave surface of the kidney that is the entry and exit for various vessels, nerves, and ureters

Superficial layer

Renal cortex

Middle layer

Renal medulla

Deepest layer

Renal sinus

Renal pyramids

Subdivision of the medulla

Renal columns

Extensions of the cortex that subdivide the renal pyramids

Renal papilla

Apex of a renal pyramid

Minor calyx

Portions of the renal sinus that connects to the renal papilla

Major calyx

Larger area formed from minor calyces merging together

Renal pelvis

Area where the major calyces merge before becoming the ureter

nephron

The ________ is the functional unit of the kidney, which consists of tubular networks that interact with a capillary network and filter blood to form urine

one million

A normal human kidney contains approximately_________ nephrons

Renal Corpuscle

Site of filtration; composed of the outer glomerular (Bowman's) capsule and the glomerulus separated by the capsular space

Glomerulus

Capillary network of fenestrated capillaries; supplied by the afferent arteriole and drained by the efferent arteriole. Surrounded by the filtration membrane

Filtration Membrane

Composed of specialized cells called podocytes with foot like extensions (pedicels) radiating from a central soma. Filtration slits formed between adjacent pedicles allow only small molecules to pass into the capsular space as filtrate

Mesangial Cells

Specialized cells positioned between the loops of the glomerulus that engulf and degrade macromolecules that get "hung up" in the filtration membrane. Also can contract to change the total surface area of capillaries available for filtration

Proximal Convoluted Tubule

Tubule between the glomerular capsule and the nephron loop

Nephron Loop

Loop of Henle; tubule between the proximal and distal convoluted tubule. Important in producing concentrated urine

Distal Convoluted Tubule

Tubule between the nephron loop and the collecting ducts

Collecting Duct

Drains urine from the nephron; empties into the minor calyces at the renal papilla

Juxtaglomerular Apparatus

Specialized structure situated at the portion of the distal convoluted tubule, which lies against the afferent arteriole

Granular, macula densa, and extraglomerular mesangial cells

Juxtaglomerular Apparatus consists of three populations of cells

granular cells

______________ _______(mechanoreceptors)-enlarged smooth muscle cells with secretory granules containing renin

macula densa cells

___________________ ______ (chemoreceptors)-group of tall, closely packed cells of the distal convoluted tubule that lie adjacent to the granular cells

extraglomerular mesangial cells

_____________ ___________ ______— cells that interconnect and pass signals between macula densa and granular cells

filtration, reabsorption, and secretion.

Urine formation results from three processes

Filtration

_________ occurs between the glomerulus and the glomerular (Bowman's) capsule

filtrate

Fluids and small solutes pass lines of filtration membrane into the capsular space where it becomes

180 liters

Approximately _______ of filtrate are produced daily by the two million nephrons in both kidneys

peritubular capillaries

Most of this filtrate will be reabsorbed by the _________ _______ from the tubular network (proximal convoluted tu-bule, nephron loop, distal convoluted tubule, and collecting duct) through osmosis and active transport

peri tubular capillaries

Materials not passed into the filtrate by filtration have the opportunity to be secreted from the ______ _______ ________ into either the distal convoluted tubule or collecting duct. This step is especially important for disposal of drug metabolites

urine

Once the filtrate reaches the collecting duct, it becomes ______ as it passes into the papillary ducts

2.5 liters

Of the approximately 180 liters of filtrate produced, only about _________ of urine are transported to the urinary bladder per day

cortical and juxtamedullary

There are two general classes of nephrons

length, location

Classification of each type is based on the _____ of the nephron loop and the ________ of the renal corpuscle

Cortical

_________ nephrons have relatively short nephron loops that extend slightly into the medulla and renal corpuscles that are located higher in the cortex of the kidney

vasa recta

The nephron loops of juxtamedullary nephrons extend deep into the medulla and are accompanied by a series of straight capillaries called the __________ _______

vasa recta

allows for the production of higher concentrated urine

renal corpuscles

The _____ __________ are located adjacent to the border between the cortex and medulla of the kidney

Renal Artery

Transports blood from the aorta to a segmental artery; main artery of the kidney

Segmental Arteries

Transports blood from the renal artery to an interlobar artery

Interlobar Arteries

Transports blood from a segmental artery to an arcuate artery; travels though the renal columns

Arcuate Arteries

Transports blood from an interlobar artery to a cortical radiate artery; travels along the border between the renal cortex and renal medulla

Cortical Radiate Arteries

Transports blood from an arcuate artery to an afferent arteriole

Afferent Arteriole

Transports blood from a cortical radiate artery to the glomerulus

Efferent Arteriole

Transports blood from a glomerulus to a peritubular capillary

Peritubular Capillaries

Transports blood around the tubular network of the nephron, allowing water and solute exchange

Vasa Recta

Transports blood around the nephron loops of juxtamedullary nephrons, allowing water and solute exchange

Cortical Radiate Veins

Transports blood from a peritubular capillary to an arcuate vein

Arcuate Veins

Transports blood from a cortical radiate vein to an interlobar vein; travels along the border between the renal cortex and renal medulla

Interlobar Veins

Transports blood from an arcuate vein to the renal vein

Renal Vein

Transports blood from an interlobar vein to the inferior vena cava; main vein of the kidney

Urinary Tract Infection (UTI)

Infection of any part of the urinary system

urethritis

Most involve infection in the lower part of the urinary system called the urethra

cystitis

urinary bladder infection

pyelitis or pyelonephritis

UTI Infection can spread into the kidneys

females

_________ are more susceptible to UTI's

external urethral orifice

The female urethra is much shorter and the ______ _______ ________ is situated close to the anal opening, this is why they are more succeptable to UTI's

Kidney stones

Hard deposits that form inside the kidney that are composed of mineral and acid salts

Vitamin D

Often caused by excess _________ _____