BIO202 Unit 6/Lab 9 Urinary System

Kidney - renal cortex

outer region of the kidney

Kidney - renal medulla

middle area of the kidney

Kidney - renal pelvis

the funnel-like dilated part of the ureter in the kidney

Renal

pertaining to the kidney

Renal artery

carries blood from the aorta into the kidney

Nephron

functional unit of the kidney that filters the blood & forms urine

Functions of the Kidneys

Main = filter wastes from blood. Also:

make urine,

convert vitamin D to active form,

metabolic waste disposal,

blood volume regulation.

Urinary Bladder - daily urine volume production

1.5 liters

Urinary bladder capacity

-a moderately full bladder is about 5 inches long and holds about 500 ml of urine

-Capable of holding twice that amount of urine

Urinary bladder - tissue type found in the walls

Transitional Epithelium

Ureters

The tubes that carry urine from the kidneys to the bladder.

Urethra

tube leading from the urinary bladder to the outside of the body

Urethra - length

Females: 3-4 cm

Males: 20 cm

Urethra - female

Carries urine out of the body

Urethra - male

Serves as the passage way for sperm and fluids from the reproductive system and urine from the urinary system. While the reproductive fluids are passing through the urethra, sphincter contract tightly to keep urine from entering the urethra.

renal ptosis

condition in which one or both kidneys drop to a lower position

-Can be caused by loss of surrounding fatty tissue capsule that holds kidneys in normal position

pyelonephritis

•Infection or inflammation of entire kidney

anuria

abnormally low urinary output (less than 50 ml/day)

nocturia

frequent urination at night

antidiuretic hormone (ADH)

•Causes principal cells of collecting ducts to insert aquaporins in apical membranes increasing water reabsorption

•As ADH levels increase -> increased water reabsorption

aquaporins

channel proteins that facilitate the passage of water

myogenic mechanism

general tendency of vascular muscle tissue to contract when stretched

pyuria

presence of white cells (pus) in the urine, usually indicating infection

Glomerulus filtration - how does it work?

The glomerular capillaries are fenestrated, allowing fairly large molecules to pass through

fenestrated

having openings

Glomerulus

A ball of capillaries surrounded by Bowman's capsule in the nephron and serving as the site of filtration in the vertebrate kidney.

urethritis

inflammation of the urethra

Internal Urethral Sphincter

smooth muscle, involuntary

External Urethral Sphincter

skeletal muscle, voluntary

micturition

another term for urination

Percentage of filtrate eventually reabsorbed back into the blood from the kidneys?

99%

Filtrate

fluid that passes from the blood through the capillary walls of the glomeruli of the kidney

Filtrate composition

-blood plasma (including water, glucose, electrolytes, ions & urea)

-minus blood proteins

In children, how does the nervous system relate to control of the urinary system?

•Incontinence normal in infants: control of voluntary urethral sphincter develops with nervous system

diuretic

agent that increases urine output

diuretics - examples

•ADH inhibitors, e.g., alcohol

•Na+ reabsorption inhibitors (and resultant H2O reabsorption), e.g., caffeine, drugs for hypertension or edema

•Loop diuretics inhibit medullary gradient formation

•Osmotic diuretics - substance not reabsorbed so water remains in urine, e.g., high glucose of diabetic patient

Urine - odor

•Slightly aromatic when fresh

•Develops ammonia odor upon standing as bacteria metabolize solutes

•May be altered by some drugs and vegetables

abnormal urine constituents

glucose (glycosuria),

proteins,

ketone bodies,

hemoglobin,

bile pigments,

erythrocytes (hematuria),

leukocytes (pyuria)

normal urine constituents

Water, urea, creatinine, electrolytes.

Glycosuria

glucose in urine

hematuria

RBCs (erythrocytes) in urine

renal calculi

-Kidney stones in the renal pelvis;

-crystallized calcium, magnesium, or uric acid salts

renal calculi - treatment

-First, pain management with NSAIDs and Narcotics, IV fluids for hydration

-Lithotripsy - non-invasive use of shockwaves to break stones so they can be passed

urinary tract infection (UTI)

invasion of pathogenic organisms (commonly E. coli bacteria) in the urinary tract, especially the urethra and bladder; symptoms include dysuria, urinary frequency, fever, chills and malaise, possible back pain

UTI - common causes in females

•Improper toilet habits, such as wiping back to front after defecation

•Most UTIs occur in sexually active women - Intercourse drives bacteria from vagina and external genital region toward bladder

dysuria

painful urination

incontinence

inability to control urination

stress incontinence

-the inability to control the voiding of urine under physical stress such as running, sneezing, laughing, or coughing

-common after childbirth (vaginal delivery) which can weaken the pelvic floor muscles & urinary sphincter

Acidosis & Alkalosis similarities

-both involve disruption of normal body pH balance

-if left untreated, both result in death

cystitis

inflammation of the urinary bladder

often caused by a urinary tract infection (UTI) and can be treated with antibiotics. Other causes include chemicals, radiation, and interstitial cystitis, and treatment options vary depending on the underlying cause.

respiratory alkalosis

A rise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2.

-corrected by the kidneys

respiratory acidosis

A drop in blood pH due to hypoventilation (too little breathing) and a resulting accumulation of Co2.

-corrected by the kidneys

metabolic acidosis

decreased pH in blood and body tissues as a result of an upset in metabolism

-compensated by an increase in ventilation to decrease blood CO2 & kidneys

metabolic alkalosis

elevation of HCO3- usually caused by an excessive loss of metabolic acids

-compensated by decrease in ventilation to increase blood CO2 & kidneys

acidosis pH

below 7.35

alkalosis pH

greater than 7.45

Alcoholism and metabolic acidosis

Alcoholism can lead to metabolic acidosis, specifically alcoholic ketoacidosis (AKA), a condition characterized by high ketone levels and an elevated anion gap, often occurring after binge drinking and poor nutrition

Hypertonic blood & relation to ADH

In response to hypertonic blood, the body releases antidiuretic hormone (ADH) to increase water reabsorption in the kidneys, thus diluting the blood and restoring osmolarity.

hypoventilate

shallow, inadequate breathing

hyperventilate

excessively rapid and deep breathing

dialysis

Process for removing waste from the blood for people with renal failure