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Biology 12 - Mackenzie > Unit 8 - Excretory System > Flashcards

Unit 8 - Excretory System Flashcards

1
Q

Define excretion

A

The removal of metabolic wastes, usually nitrogenous, from the body

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2
Q

Define defecation

A

The process which rids the body of indigestes, un absorbed food remains, plus bacteria

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3
Q

What is excretion of waste products important for?

A

Maintaining homeostasis in the body

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4
Q

List the 4 main nitrogenous wastes

A

Ammonia
Urea
Uric acid
Creatine

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5
Q

Where is ammonia formed?

A

In liver cells by deamination

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6
Q

What are some qualities of ammonia?

A

Ammonia is highly toxic and soluble in water
Some ammonia is also secreted as an ammonium ion (NH4+)

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7
Q

What’s the formula for ammonia?

A

NH3

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8
Q

Where is urea formed?

A

In the liver by combination of CO2 and 2 ammonia molecules

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9
Q

What are some qualities of urea?

A

It’s less toxic
And less soluble in water

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10
Q

What are some qualities of urea?

A

It’s less toxic
And less soluble in water

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11
Q

How is uric acid formed?

A

When nucleotides are broken down

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12
Q

What can uric acid do?

A

Sometimes it can crystallize in joints, causing painful swelling called gout

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13
Q

How does creatine form?

A

Forms from break down of creatine phosphate, a high energy phosphate reserve molecule in muscles

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14
Q

What does creatine help with?

A

Helps recycling of ADP back to ATP by giving it a phosphate

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15
Q

What does creatine help with?

A

Helps recycling of ADP back to ATP by giving it a phosphate

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16
Q

How do fish excrete nitrogenous wastes?

A

Fish secrete ammonia directly into the water through their gills

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17
Q

How do birds and reptiles excrete nitrogenous wastes?

A

They secrete uric acid when they poop

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18
Q

How do humans excrete nitrogenous wastes?

A

Humans and all other mammals produce urea and excrete the waste product through urination

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19
Q

What are some other waste products?

A

Water
Salt
CO2
Bile pigments

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20
Q

Describe the waste product water

A

End product of metabolism (cellular respiration in the mitochondria)

Plays a major role in blood pressure

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21
Q

Describe the waste product salts

A

Excreted maintaining proper concentration in blood ph, osmotic pressure and electrolyte balance

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22
Q

Describe the waste product salts

A

Excreted maintaining proper concentration in blood ph, osmotic pressure and electrolyte balance

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23
Q

Describe the waste product CO2

A

End product of metabolism (cellular respiration in the mitochondria)

Excreted primarily from lungs

Solvable in blood, combines with H2O to make H2CO3/HCO3-

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24
Q

Describe the waste product bile pigments

A

From heme portion of Hb (blood)
Mixed into bile by liver and stored in gall bladder

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25
Q

Describe the waste product bile pigments

A

From heme portion of Hb (blood)
Mixed into bile by liver and stored in gall bladder

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26
Q

What organs are s’associât es with the excretion of waste products?

A

Lungs
Kidneys
Skin
Liver

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27
Q

What is urine composed of?

A

95% water
2% urea
1.63% salt ions
0.1% creatine
0.05% ammonia
0.03% uric acid

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28
Q

What are the 4 functions of the urinary system?

A

Filter blood and remove wastes
Osmoregulation
Maintain blood ph at 7.4
Secretes an enzyme and hormone that regulate water retention

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29
Q

Explain osmoregulation

A

Maintaining blood volume and pressure
The kidney can increase or decrease salt retention in the blood
Kidneys also help maintain blood levels of other ions such as potassium, bicarbonate and calcium in the blood

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30
Q

What does it mean if there is more salt in the blood?

A

There is a greater blood volume and pressure because salt draws water into the blood via osmosis

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31
Q

What does it mean if there is less salt in the blood?

A

Less blood volume and pressure because less salt draws less water into the blood via osmosis

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32
Q

What does it mean if there is less salt in the blood?

A

Less blood volume and pressure because less salt draws less water into the blood via osmosis

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33
Q

How is blood ph maintained?

A

By excreting hydrogen ions and reabsorbing the bicarbonate ions as needed

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34
Q

What is the ph of human urine?

A

6 or lower because food is often acidic

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35
Q

What is step one to secretion?

A

The kidneys release renin, an enzyme that leads to the secretion of the hormone aldosterone from the adrenal cortex, which leads to reabsorption of sodium ions and more water into the blood

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36
Q

What is step two to secretion?

A

The kidneys also release ADH, which causes the kidneys to reabsorb more water into the blood

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37
Q

Describe the kidneys

A

Paired, bean shaped reddish brown organs.
About the size of a fist
Covered by a tough fibrous connective tissue called a renal capsule

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38
Q

Where are the kidneys located?

A

Near the small of the lower back, some protection from rib cage

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39
Q

Where are the kidneys located?

A

Near the small of the lower back, some protection from rib cage

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40
Q

Where are the kidneys located?

A

Near the small of the lower back, some protection from rib cage

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41
Q

What does the adrenal gland do?

A

It sits on top of each kidney and produces hormones

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42
Q

What does the renal artery do?

A

Brings unfiltered blood into the kidney

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43
Q

What does the renal vein do?

A

Takes filtered blood away from the kidney

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44
Q

What are ureters?

A

Muscular tubes about 25 cm long and 5 mm in diameter

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45
Q

What do ureters do?

A

Move urine from kidneys to bladder via peristalsis, about 1-2 squirts per minute

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46
Q

How much urine does a human produce per day?

A

1-2 litres

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47
Q

What does the urinary bladder do?

A

Stores urine until it is expelled from the body

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48
Q

What does the bladder wall have?

A

Stretch receptors which make the walk expandable and notify the brain when it’s full

49
Q

What do the two sphincters in the bladder do?

A

Control the exit of urine to the urethra because the internal sphincter is composed of skeletal muscle

50
Q

What is the urethra?

A

A small tube that extends from the bladder to an external opening
In females 4cm long
In males 20 cm long

51
Q

In females how is the reproductive system?

A

Separate

52
Q

In males the reproductive system is merged, how does it work?

A

The urine use the urethra during urination and semen uses the urethra during ejacualtion

53
Q

What is step one in the process of urination?

A

When the bladder fills to about 250ml with urine, stretch receptors send sensory nerve impulses to the spinal cord

54
Q

What is step two in the process of urination?

A

Motor nerve impulses from the spinal cord cause the urinary bladder to contract and the sphincters to relax

55
Q

What is step three in the urination process?

A

Urination occurs

56
Q

What is step four of the urination process?

A

In older children and adults the brain controls this reflex, so urination is delayed until a suitable time

57
Q

What is step four of the urination process?

A

In older children and adults the brain controls this reflex, so urination is delayed until a suitable time

58
Q

What is the renal cortex?

A

Outer region of the kidney
Consists of about 1 million filtration units called nephrons as well as blood capillaries
Site of blood filtration

59
Q

What is the renal medulla?

A

Inner region of the kidney, not including the pelvis
Consists of a few more nephrons, but mostly collecting ducts which make up the renal pyramids
Bring filtered liquid waste to the pelvis (urine)

60
Q

What is the renal pelvis?

A

Collects urine and sends it down the ureter to the bladder

61
Q

Where can kidney stones be formed?

A

In the pelvis. There are 4 types and they are all a combo of calcium, phosphate, oxolate, or uric acid

62
Q

What is a nephron?

A

A filtration unit found in the kidney; urine formation occurs here

63
Q

What does each nephron have?

A

It’s own blood supply, including 2 capillary regions

64
Q

How much does the nephron process each day?

A

About 180 L of filtrate but excretes only 1.5 L of urine

65
Q

What are the parts of the nephron?

A

Bowman’s capsule
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Collecting duct

66
Q

What are the parts of the capillary network?

A

Afférent arteriole
Glomerulus
Efferent arteriole
Peritubular capillaries
Vasa recta

67
Q

What is the overall pathway of blood in the kidney?

A

Renal artery, afférent arteriole, glomerulus, efferent arteriole, peritubular capillaries/vasa recta, venule, renal vein

68
Q

What is the process of urine formation?

A
  1. Glomerular filtration
  2. Tubular reabsorption
  3. Reabsorption of water
  4. Tubular secretion
69
Q

Where does urine go once formed in the nephron?

A

Goes down the collecting duct into the renal pelvis, ready for excretion

70
Q

Where does glomerular filtration occur?

A

In the bowman’s capsule

71
Q

Describe the bowman’s capsule

A

Cup like structure that surrounds a mass of blood vessels called the glomerulus

72
Q

Does the afferent arteriole bring blood into or out of the glomerulus?

A

Into

73
Q

What is the size of the afferent and efferent arterioles?

A

Afferent is large
Efferent is small

74
Q

What do pores allow for?

A

Allows easy passage of small molecules from the blood into the bowman’s capsule

75
Q

All small molecules move into the nephron to form what?

A

The filtrate where movement is passive and non specific

76
Q

What happens to large blood components?

A

RBCs, WBCs, platelets and proteins do not filter across and remain in the blood

77
Q

What does the smaller diameter of the efferent arteriole help with?

A

Contributes to the pressure applied at the glomerulus

78
Q

Why is the blood leaving the glomerulus more concentrated?

A

Most of the water and smaller molecules have been removed

79
Q

What is the pressure of the afferent and efferent arterioles?

A

Afferent - higher
Efferent - lower

80
Q

What level of urea, glucose, and water is in the afferent and efferent arterioles?

A

Afferent - high
Efferent - low

81
Q

Where does tubular reabsorption occur?

A

Primarily in the proximal and distal convoluted tubules

82
Q

What does tubular reabsorption connect and what surrounds it?

A

It connects the bowman’s capsule to the loop of henle and is surrounded by the peritubular capillary network

83
Q

What do the cells lining some areas of the nephron have and why? (Tubular reabsorption)

A

Microvilli to increase surface area and reabsorption of desired filtrate components like glucose, aa, and water back into the blood stream

84
Q

How is movement in tubular reabsorption?

A

Movement is selective and active
Each cell in the pct has many mitochondria for energy for active transport of molecules

85
Q

In tubular reabsorption how much water goes back into the blood and by what?

A

About 75% moves passively by osmosis

86
Q

In tubular reabsorption are all things reabsorbed into the blood?

A

No, some water, excess salts, and wastes are not reabsorbed and move onto the loop of henle

87
Q

Where does the reabsorption of water occur mainly?

A

In the loop of henle and the collecting ducts

88
Q

What does the descending loop of henle allow for?

A

Allows water to leave the nephron where it is absorbed back into the capillaries

89
Q

What does the ascending loop of henle have and what does it do?

A

It has an impermeable wall and does not allow water to leave. It transports put salt into the medulla and blood capillaries

90
Q

What direction does blood flow in the vasa recta?

A

Moves in the opposite direction than the filtrate in the nephron

91
Q

What allows for slate to move into the blood at the ascending loop of henle?

A

The opposite flow of blood

92
Q

What does salt do in the descending loop of henle?

A

Sucks the water into the blood by osmosis

93
Q

What happens when the loop of henle descends deep into the medulla of the kidney?

A

The more concentrated the interstitial fluid surrounding the nephron becomes (hypertonic). This is due to slat and urea being more concentrated in the centre of the kidney and contributes to a greater pull of water out of the nephron

94
Q

What is the wall of the collecting ducts permeable to?

A

Water and urea

95
Q

As the collecting duct moves down into the concentrated medulla what happens?

A

The water is sucked out and put back into the blood and medulla via osmosis

96
Q

What happens with the loss of water in the collecting duct?

A

The urea in the filtrate becomes more concentrated. Because there is so much urea in the collecting duct, some of it diffusés down its concentration gradient and back into the blood and medulla

97
Q

Where does tubular secretion occur?

A

Mostly in the proximal and distal consulted tubules

98
Q

What enters into one collecting duct?

A

Several convoluted tubules, they then carry urine to the renal pelvis

99
Q

When the blood is acidic what happens at the duct?

A

Excess H+ ions are put back into the filtrate, making urine more acidic

100
Q

When the blood is acidic what else does the duct do?

A

The bicarbonate ions are actively transported back into the blood.

101
Q

What happens to the kidneys if you are dehydrated?

A

The Kinsey’s can excrete a small, concentrated volume of urine and reabsorb the majority of water from the filtrate.
The urine will be very little and dark yellow

102
Q

What happens to the kidneys if you are dehydrated?

A

The Kinsey’s can excrete a small, concentrated volume of urine and reabsorb the majority of water from the filtrate

103
Q

If you have an excessive amount of fluid what happens to your kidneys?

A

They excrete a large, dilute volume of urine, with very little water being reabsorbed from the filtrate
You will have lots of pale urine

104
Q

How do we maintain the proper amount of water in our bodies?

A

It is controlled homeostatically with two hormones
Antidiuretic hormone (ADH)
Aldosterone

105
Q

What does antidiuretic hormone control?

A

This hormone controls water reabsorption with a negative feedback cycle

106
Q

What makes ADH and where is it stored?

A

The hypothalamus makes ADH
It is stored and released from the posterior pituitary gland

107
Q

What happens with ADH when you have low blood volume? (Dehydrated)

A

The osmoreceptor cells in the hypothalamus triggers the posterior pituitary to release ADH

108
Q

Where does ADH move through and what does it increase?

A

ADH moves through the blood to the kidneys and increases the permeability of the distal convoluted tubule and collecting ducts to water, causing more water to be reabsorbed into the blood and increases blood volume

109
Q

With ADH when water is being removed from the filtrate what happens?

A

The concentration of urine increases. Your urine will be less and dark

110
Q

What is ADH mechanism controlled by?

A

Negative feedback. Once blood volume is back to normal and osmolarity is lower, the posterior pituitary gland stops releasing ADH

111
Q

What does alcohol do with ADH?

A

It inhibits the release of ADH, causing excessive loss of water in the urine and dehydrating the body. Leads to a hangover

112
Q

What is the juxtaglomerular apparatus?

A

A specialized tissue that surrounds the afférent arteriole of the kidney. It measures blood pressure

113
Q

What happens with JGA when BP drops?

A

The JGA releases an enzyme celles renin, which activates angiotensin

114
Q

What is angiotensin?

A

A protein made by the liver which is always circulating around the blood

115
Q

What does angiotensin do?

A

Stimulates the adrenal gland on the kidneys to release the hormone aldosterone

116
Q

What does aldosterone do?

A

Tells the distal convoluted tubules of the nephrons to reabsorb lots of salt back into the blood. Water then goes into the blood through osmosis which increase BP

117
Q

What else does angiotensin do?

A

Causes vasoconstriction of the arterioles. BP rises

118
Q

What happens if BP is too low?

A

There is not enough pressure to filter the blood properly
Kidneys can not rid the body of drugs and toxins
Not enough blood reaches the brain so you may faint

119
Q

What happens if BP is too high?

A

The glomerulus may be damaged or burst
Blood cells and proteins will then pass through the nephron and into the urine

Biology 12 - Mackenzie (9 decks)

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