urinary system

Question 1

What is homeostasis

Answer 1

refers to the maintenance of a relatively constant internal environment independent of changes in the external environment

Question 2

Provide some examples of homeostasis?

Answer 2

• blood plasma levels of pH
• osmoregulation concentrations
• Glucose level consistency for cells especially brain and heart
• blood pressure
• hormone levels
• thermoregulation
• metabolic wastes can’t build up to toxic levels

Question 3

What is thermoregulation

Answer 3

Bodies ability to maintain a consistent body temperature

Question 4

Define osmoregulation

Answer 4

the maintenance of internal body fluids in terms of water and dissolved solutes, such as salt, relative to the surrounding environment

Question 5

What is the role of the urinary system (kidneys)

Answer 5

• involved in osmoregulation
• excretion of metabolic wastes
• controls water and ion balance in body

Question 6

What % of the adult body is composed of water?

Answer 6

55-60%

Question 7

what are the sources of water within the body

Answer 7

• preformed water

- metabolic water

Question 8

What is preformed water

Answer 8

water from ingested foods and liquids

Question 9

What is metabolic water

Answer 9

water created by dehydration synthesis reactions

Question 10

How is water lost in the body in descending order

Answer 10

• kidneys
• skin perspiration
• skin evaporation
• lungs
• GI tract

Question 11

How do fluid levels remain constant?

Answer 11

usually water gain is equal to water loss

Question 12

Describe the fluid compartments of the body

Answer 12

water in our bodies is found both inside cells and outside cells

• intracellular fluid (cytosol) - within cells
• extracellular fluid - fluid outside cells

Question 13

What are the subdivisions of extracellular fluid?

Answer 13

• interstitial fluid - btwn cells in tissues
• blood plasma
• lymph
• cerebrospinal fluid
• others

Question 14

Describe Fluid composition within urinary system

Answer 14

• fluids mainly consist of water but also have dissolved solutes
• dissolved solutes can be ions, proteins, sugars, hormones, other specialized molecules

Question 15

What are the most prevalent ions in body fluids?

Answer 15

• sodium
• chloride
• potassium
• calcium
• bicarbonate
• phosphate

Question 16

Define fluid balance

Answer 16

• refers to the correct amount of water in the correct places
• implies a balance of solutes including electrolytes

Question 17

Describe how the kidneys excrete of metabolic wastes

Answer 17

• metabolic wastes are formed mainly in the liver, which converts amino acids into molecules to be used for cellular respiration
• Kidneys remove wastes from the blood
• nitrogenous wastes are produced which include ammonia, urea, and uric acid
• Liver must convert ammonia to uric acid or urea due to it being very toxic in the body
• uric acid is the most energetically costly for production (requires lots of ATP to make it)

Question 18

What is a nitrogenous waste?

Answer 18

• a toxic byproduct containing nitrogen produced in the liver due to the breakdown of amino acids
• Very toxic in the body and must be converted.

Question 19

What is the process of creating uric acid

Answer 19

• Amino acid
• Ammonia
• Urea
• Uric Acid

Question 20

What does the urinary system consist of?

Answer 20

• paired kidneys
• paired ureters
• urinary bladder
• single urethra

Question 21

What is the function of the ureters

Answer 21

Drain the kidneys

Question 22

What is the function of the urinary bladder

Answer 22

stores urine

Question 23

What is the function of the urethra

Answer 23

drains bladder

Question 24

What is the role of the kidneys?

Answer 24

• filters approx. 2000 litres of blood / day
• monitors and regulates water, ion, sugar, and other molecules
• removes a variety of potentially harmful substances

Question 25

Describe the structure of the kidney

Answer 25

- pair of kidney bean shaped organs with 2 regions - outer called cortex - inner called medulla - Composed of tubules called Nephrons

Question 26

What are nephrons

Answer 26

- tubules surrounded by interstitial fluid and blood capillaries - over 1 million tiny nephrons / kidney

Question 27

What is the role of nephrons?

Answer 27

- filter the urine (filtration) | - allow for water and important solutes to be reabsorbed back into the blood (reabsorption and secretion)

Question 28

Describe the structure of a nephron

Answer 28

- coiled tubes that pack tightly together - They have regions in order they are - bowmans capsule - proximal convoluted tubule - loop of henle - distal convoluted tubule - collecting ducts

Question 29

Describe the path of urine drainage

Answer 29

- converge at the renal pelvis - empties in a single ureter - ureter exits the kidneys and leads to the urinary bladder - bladder is drained by the urethra

Question 30

Describe renal physiology

Answer 30

- 3 processes (filtration, resorption, secretion) occur in the human kidney involved in osmoregulation and metabolic waste excretion resulting in the formation of urine - Blood arrives at the kidney through renal artery which branches until single supplies the glomerulus or tuft of capillaries where the blood is filtered

Question 31

Describe how the filtration function of the kidney works

Answer 31

- occurs at the renal corpuscle consists of bowman's capsule of the nephron and the glomerulus - high blood pressure forces almost everything out of the glomerulus and into the lumen of the bowman's capsule with the exception of formed elements - forms around 200 liters of filtrate each day - only forms 1-2 liters of urine rest is reabsorbed - Most of the filtrate will be reabsorbed by blood before urine is formed

Question 32

What is blood pressure not able to force out of the glomerulus?

Answer 32

- formed elements | - medium and large proteins

Question 33

What does filtrate consist of?

Answer 33

water, hydrogen ions Na+Cl, ammonia, urea, glucose, amino acids, vitamins

Question 34

Describe the secretion process of the kidneys

Answer 34

- selective addition of solutes from the blood to filtrate occurring farther along the nephron - waste products and excessive ions are eliminated in the urine this way - important for regulating pH

Question 35

Describe the reabsorption process of the kidneys

Answer 35

- selective removal of necessary substances from the filtrate across the nephron and back into the blood - includes reabsorption of sugars, vitamins, amino acids, water, sodium chloride, bicarbonate ions

Question 36

What hormone targets the kidneys and what is it's function?

Answer 36

ADH acts on the nephron and alter urine volume and also blood volume and pressure

Question 37

What is the composition of normal urine

Answer 37

- water - metabolic wastes - urea, ammonia, uric acid - ions - drugs, antibodies, water soluble vitamins

Question 38

What should not be found in normal urine

Answer 38

- glucose - more than a trace amount of protein - red blood cells - white blood cells - bacteria or yeast

Question 39

Why should glucose not be found in urine?

Answer 39

- indicator of diabetes mellitus | - blood glucose levels are abnormally high and the quantity filtered cannot be completely reabsorbed

Question 40

Why should trace amounts of protein not be found in urine

Answer 40

high blood pressure, kidney disease, or infection

Question 41

Why should red blood cells not be found in urine

Answer 41

sign of kidney disease (filter damage)

Question 42

Why should white blood cells not be found in urine

Answer 42

indicator of infection

Question 43

Why should bacteria or yeast not be found in urine

Answer 43

indicator of infection