1. Regulation of the Internal Environment
Chapter 32
Regulation of the
Internal Environment

2. Feedback allows our bodies to regulate its’ contents and conditions
Positive F’b: causes an increase to increase even more; ex lactation, contractions, bloodclotting
Negative F’b: COUNTERACTS the direction of change that is occurring.
Neg F’b maintains homeostasis

3. (no notes right now)
It’s like this: Ideal Level

4. Level too High Ideal Level
Negative Feedback will bring the level back down
Level too High
Ideal Level

5. Ideal Level

6. Ideal Level Level too Low
Negative Feedback will bring the level back up
Ideal Level
Level too Low

7. Ideal Level
Neg. feedback counteracts the direction of change

8. Hey
About that diagram…
Let’s talk it over…

9. Temperature Regulation of the body is accomplished by

10. How our temp. is regulated:
Temperature increases - vessels dilate and heat escapes
Temperature decreases –vessels constrict and you shiver

11. Hormones our bodies’ chemical messengers
When levels od different nutrients decrease, neg. feed back causes hormone production to increase.
As nutrient levels rise, hormone levels fall…

12. Regulation of water: Kidneys: collect and excrete Skin: evaporates
Breathing: exhales Drinking replenishes!

13. Regulation of wastes: Cells produce waste These are collected
Once collected they’re excreted

14. Look at the flowchart on page 3 in your notepacket…

16. Elimination is of ingested food that was NOT ___
It’s the removal of food that could not be digested (& absorbed, then used for metabolism)
Feces

17. Excretion must begin with?
It is the removal of wastes from metabolic activity (chemical reactions) in cells.
Includes ,urine, sweat, exhaling

18. What are 2 metabolic wastes we have already learned about?
1. CO2
2. H2O

19. Other Metabolic wastes…
3. inorganic salts
sodium chloride (NaCl)
potassium sulfate (KSO4)
4. nitrogenous wastes
Contain N
Ammonia, urea, uric acid

20. Deamination
Break down of extra amino acids to use for E
Amino group is removed
Ammonia (NH3) is formed

21. Deamination of amino acids

22. LOW HIGH MED MED HIGH NON WASTE ATP TO PRODUCE TOXICITY AMMONIA (NH3)
NITROGENOUS
WASTE
ATP TO
PRODUCE
TOXICITY
AMMONIA (NH3)
UREA
URIC ACID
LOW
HIGH
MED
MED
HIGH
NON

23. Animals that make uric acid Conserve Water
NITROGENOUS
WASTE
SOLUBILITY
Water needed to remove
AMMONIA (NH3)
UREA
URIC ACID
Large
amts
HIGH
Animals that make uric acid Conserve Water
MED
amts
MED
Small
amts
LOW

24. environment influences which nitrogenous waste isexcreted.
Humans excrete primarily UREA.

25. 3rd
2nd
1st

26. Human Excretory System
Function:
1. regulate contents of the blood
KIDNEYS control what is removed and retained

27. Human Excretory System
2. remove nitrogenous wastes from the blood . Produces urine

28. The Excretory System:
Define the difference between EXCRETION and ELIMINATION

29. A simple system for excretion!

30. Organs of Excretory System
2 Kidneys:
Bean shaped
Filter wastes from blood

31. Organs of Excretory System
2 Ureters:
tubes that carry urine from kidneys to bladder

32. Organs of Excretory System
1 Urinary Bladder:
Muscular (smooth) sac
Storage of urine

33. Organs of Excretory System
1 Urethra:
bladder to outside of the body

34. Renal artery Renal vein Cortex Medulla Pelvis Ureter
Kidney, a closer look
Renal artery
Renal vein
Cortex
Medulla
Pelvis
Ureter

35. Renal vein
Renal artery
Adrenal
glands
Kidney
Ureter
Bladder
Urethra

36. Nephron Microscopic filters that fill each kidney How many per kidney?
~ 1 million

37. Loop of Henle Collecting duct Capillaries A detailed look at a nephron
Convoluted
tubule
Bowman’s capsule
Renal arteriole
Collecting
duct
glomerulus
Renal
venule
Capillaries
Loop of Henle
A detailed look at a nephron

38. Nephron Animation

39. 1. (p6) Urine formation begins with Filtration
Solutes in the blood’s plasma diffuse from the glomerulus into the Bowman’s capsule

40. All cells and large molecules remain in the blood vessels
Ex., large proteins, red blood cells, white blood cells, platelets

41. (this forms the ‘filtrate’)
b. all small molecules, both good and bad, diffuse into the Bowman’s capsule
AA’s, H2O, glucose,
urea, salts, toxins, hormones
(this forms the ‘filtrate’)

42. 2. Then Reabsorption
Useful substances in the tubules and the loop of Henle diffuse back into the capillaries!
Ex AA’s, H2O, C6H12O6

43. Lg molec’s remain
Sm molec’s cross

44. Water, nutrients are reabsorbed into the blood stream here

45. Complete pg 8…

46. Regulating Water Balance
Using Negative Feedback
As water drops, conc of dissolved things increases
That change is measured by the brain
We respond by reabsorbing more water from the filtrate in our kidneys’ nephrons!

47. Low water, high solute detected by hypothalamus
Pituitary gland releases hormone ADH
Kidneys reabsorb water
Less Water in the Urine!

48. Conversely… More Water in the Urine! High water, low solute
Pituitary gland does not release ADH
Kidneys reabsorb less water
More Water in the Urine!

49. Can you live without your kidneys?

50. Causes of Kidney disease
Genetics
Pathogens
Injury
Poisoning

51. Transplant
Can live with 1 kidney
Risk of rejection (self vs. non-self)

52. Treating Kidney diseases is tough:
Dialysis
Blood is pumped through tubes that function like nephrons and returned to the body

53. The Liver helps
maintain homeostasis

54. 1. The liver manages carb storage
Glucose may be converted to Glycogen, for storage in the liver

55. 2. Role in digestion The liver produced bile stored in gallbladder
used in small intestine to emulsify fats

56. 4. The liver produces clotting proteins that are in the blood plasma to react to platelets.

57. 5. the liver detoxifies Ex: NH3 is turned into?
Inactivates toxic substances (alcohol to acetaldehyde)
Released back into the blood, transported to kidneys to be filtered out into urine

58. 5. Roles in excretion b. Urea formation
AA+ H2O  E +NH3  urea in liver, kidneys, to urine and OUT!

59. Liver Diseases
Hepatitis: a viral infection – many types, named A, B & C etc.

62. Liver Diseases
Cirrhosis
Caused by alcohol abuse or Hepatitis B

64. Other excretory organs
Lungs: excrete what metabolic waste(s)? C6H12O6+ 6O2 6CO2+ 6H2O+ 38ATP
Skin: excretes what metabolic waste(s)

65. Part 2
Hormones function in
growth, development,
reproduction and
homeostasis

66. Regulation: controlling the rate of reactions
Two body systems are involved in regulation:
Nervous, Endocrine
We have already studied the nervous system

67. What is an Excretion? (review: see box)
Removal of waste product chemicals produced in a cell

68. So what is a secretion?
Discharge of a useful substance produced in cells/organs, needed somewhere else ex mucous in stomach, oil on scalp

69. Organs that make and release secretions.
& what are glands?
Organs that make and release secretions.

70. The 2 types of glands:
1. Exocrine
2. Endocrine

71. Exocrine Glands: discharge secretion into a DUCT

72. Endocrine Glands: Discharge secretion into THE BLOOD STREAM

73. Look at the list of
Exocrine glands and
their secretions.
Fill in the missing
information:

74. Exocrine glands do
not secrete
_______________
hormones

75. Pineal
Hypothalamus
Pituitary
Thyroid
Parathyroid
Thymus
Adrenal
Pancreas
Ovary
Testes

76. Hormones regulate metabolism
Some horomones….
Start a process
Stop a process
Accelerate a process
Slow down a process

77. Hormones are chemical messengers
Produced:
by endocrine glands
Transported:
in bloodstream

78. Hormones are chemicals
Target cell: respond to hormone (receptors)
Which body cell has the correct receptors for the hormone? A C B

79. 2 types of hormones: Steriod: Lipid-like pass through cell membrane
one-messenger system
Ex: testosterone, Estrogen

80. One-Messenger Model (Steroid Hormones)

81. 2 types of hormones: Protein: Amino acid chains
Cannot pass through cell membrane
two-messenger system
Ex: insulin, adrenaline

82. Two – Messenger Model (Protein Hormones)

83. Excreted in the urine.
Hormones are not recycled

84. Hormones use negative feedback.
Hormone production is constantly turned on & off to maintain H _ _ _ _ _ _ _ _ _

86. INSULIN & GLUCAGON SECRETED BY THE PANCREAS
REGULATE BLOOD GLUCOSE LEVELS
EXAMPLE OF NEGATIVE FEEDBACK REGULATION

87. 1. (# THE DIAGRAM) HIGH CONCENTRATION OF GLUCOSE IN BLOOD
STIMULATES

88. 2. PANCREAS SECRETES INSULIN INTO THE BLOODSTREAM
WHICH CAUSES

89. 3. BODY CELLS TAKE IN GLUCOSE,
(or store it as glycogen in liver)
WHICH RESULTS IN

90. 4. WHICH LOWERS THE GLUCOSE IN THE BLOOD!
WHICH NOW STIMULATES…

91. 5. SECRETION OF GLUCAGON FROM THE PANCREAS
THIS CAUSES

92. (Liver glycogen is converted to glucose)
6. STORED E TO BE UNSTORED
(Liver glycogen is converted to glucose)
RESULTING IN

93. 1. GLUCOSE IN BLOOD RISES
NEGATIVE FEEDBACK STRIKES AGAIN

94. Blood Calcium Feedback Loop

95. ACT AS CHEMICAL MESSENGERS
HORMONES
ACT AS CHEMICAL MESSENGERS

96. Read p 15…
Turn to p 21, complete all you can w/out referring back to 15.
After doing all you can from memory, refer back to 15 and complete

98. Please Complete Pages 18, 20 & 22

100. Hormones & Homeostasis
Hormones are chemical messengers
They are transported in the blood
Regulate metabolism by giving feedback, stimulating changes in the body

101. Hormones & Homeostasis
Endocrine glands organs that produce regulatory hormones carried in the blood

102. Target cells respond to a specific hormone, because they have receptors for that hormone

103. Endocrine glad cell
diffusion

104. Back to page 21:
The amount of glucose in the blood is regulated
The hormone that regulates it is mainly insulin
(Insulin is helped by another hormone called glucagon)
They’re produced by an endocrine gland called the pancreas, found in the digestive system
Complete the flow chart on p 21