Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
23 Cards in this Set
- Front
- Back
|
What are the two functions of the urinary system?
|
Removal of waste products as urine and maintenance of the fluid and electrolyte balance.
|
|
|
What are the principle structures of the urinary system?
|
Ureters, kidneys, urinary bladder and urethra.
|
|
|
What are the kidneys?
|
Solid bean shaped organs that lie in the retroperitoneal space behind the abdominal cavity. They filter blood, remove wastes and excrete waste as urine.
|
|
|
Label a diagram of the kidneys?
|
Label diagram
|
|
|
What is the nephron?
|
The nephron is the functional unit of the kidney. It performs three processes; Glomerular filtration, tubular reabsorption and tubular secretion. These three processes contribute to the filtering of the blood.
|
|
|
How is urine formed?
|
Blood flows through filtration membranes where the blood is filtered. Here urine is formed. Salts, glucose and amino acids are reclaimed from or excreted into the urine as necessary.
|
|
|
What is the rate at which blood is filtered into the urine called?
|
The glomerular filtration rate.
|
|
|
What effect does high blood pressure have on urine volume?
|
High blood pressure increases the GFR and therefore produces more urine. Low blood pressure results in increased water retention.
|
|
|
What effect to diuretics have on urine production?
|
Inhibits sodium reabsorption into the body via the collecting tube. This has the effect of decreasing the amount of water taken back. IE It increases urine production and also helps to reduce hypertension which diuretic drugs are most often used for.
|
|
|
What is the effect of heat on urine production?
|
When you get cold vasoconstriction causes an increase in blood pressure. This increases urine production. Cold = More Pee. Heat can lead to dehydration through sweating therefore reduced urine production.
|
|
|
What are the effects of emotions on urine production?
|
Stresses and emotions can cause increased produciton of ADH. This increases production of urine.
|
|
|
What is the effect of blood concentration on urine output?
|
High concentrations of solutes in the blood such as alcohol and caffiene will increase urine production as more urine is produced in order to dilute and filter out these wastes.
|
|
|
What is the principle of hemodialysis?
|
The blood circulates through a dialysus machine that functions in a similar way to the normal kidneys. The patient is usually connected to the machine via a shunt.
|
|
|
What are the physical characteristics of urine?
|
Yellow or amber varying with concentration and diet.
Clear to slighty hazy 1-2 Litres in 24 hours but varies significantly pH 4.5 - 8.0 Specific gravity slighty heavier than water (1.015-1.025) |
|
|
What is the chemical composition of urine?
|
Human urine consists primarily of water, with organic solutes including urea, creatinine, uric acid, and trace amounts of enzymes, carbohydrates, hormones, fatty acids, pigments, and mucins, and inorganic ions such as sodium (Na+), potassium (K+), chloride (Cl-), magnesium (Mg2+), calcium (Ca2+), ammonium (NH4+), sulfates (SO42-), and phosphates (e.g., PO43-).
|
|
|
What is the micturition reflex?
|
Caused by the stretching of the bladder walls. This spinal refex causes contraction of the bladders smooth muscles producing the urge to void.
|
|
|
What are the ureters?
|
The ureters are a pair of thick walled hollow tubes that carry urine from the kidneys to the urinary bladder. The ureter walls contain smooth muscle that maintains the flow of urine.
|
|
|
What is the urinary bladder?
|
The place where urine is stored until excreted. The bladder is hollow and muscular. When the walls of the bladder are stretched, nerves are stimulated producing a spinal (micturition) reflex.
|
|
|
What is the urethra?
|
Urine drains from the bladder to the outside of the body via the urethra. Location depends on gender.
|
|
|
What are the effects of aging on the urinary system?
|
The filtration function of the renal system declines by 50% between 20 and 90 years of age. Aging kidneys respond less efficiently to hemodynamic stress, and to fluid and electrolyte imbalances.
|
|
|
What are the two hormones that control kidney function and what do they do?
|
Aldosterone (produced by the adrenal glands). This increases the rate of sodium and water resorption from the tubules to the blood. More aldosterone = more retention of sodium and chloride.
ADH (antidiuretic hormone) regulates the permiability of the distal tubules and collecting ducts. When levels are high these structures are impermiable to water resulting in concentrated urine. A lack of ADH results in lots of very dilute urine. |
|
|
How does the urinary system help with the acid / base balance?
|
When the plasma pH drops, hydrogen ions (acid) are excreted, and bicarbonate ions (base) are retained.
• Conversely, when the plasma pH rises hydrogen ions are retained in the body, and bicarbonate ions are excreted. |
|
|
Identify the external and internal gross anatomical features of the kidneys?
|
Cortex – outer region.
Medulla – middle layer containing the renal pyramids (urine collecting tubules). Renal Pelvis – (external) – tube that fills sinus at the level of the hilum. |
