1. Hormones & Homeostasis
Endocrine System
Hormones & Homeostasis

2. Quick Review! Neuron Directional Flow
Dendrite cell body axon axon/synaptic terminal across the synapse Dendrite of another neuron

3. Neurotransmitters
Messages are sent from one neuron to another by jumping across the synapse
Neurotransmitters, or chemicals, are released to help the impulse to be carried

4. LG: How does the Endocrine system help to maintain homeostasis? 1/6/14
Do Now:
Complete the handout on the nervous system

5. LG: How does the Endocrine system help to maintain homeostasis?
Goiter
Grave’s disease
Dwarfism vs. Gigantism

6. Overview http://www.youtube.com/watch?v=jdJpLvSTZMU

7. Endocrine glands (cells or organs)
Pineal gland (“3rd Eye”)
Pituitary gland
Thyroid gland
Thymus
Adrenal gland
Pancreas
Ovary
Testis
Gonads

8. Homeostasis Homeostasis maintaining internal balance in the body
also called “dynamic equilibrium”
example: body temperature
humans:
too cold = shiver
too warm = sweat
Insulin lowers blood sugar

9. Regulation How we maintain homeostasis? nervous system
releases neurotransmitters (NTs) as nerve signals to control body functions
endocrine system
releases hormones as chemical signals to control body functions

10. Controlling Body Temperature
Nervous System Control
Feedback
Controlling Body Temperature
nerve signals
brain
sweat
dilates surface blood vessels
high
body temperature
low
constricts surface blood vessels
shiver
brain
nerve signals

11. Q: Feedback mechanisms are best described as processes that help
(1) reduce hormone levels to below normal in the blood
(2) destroy hormones in the blood
(3) directly control muscle contraction in the leg
(4) keep body conditions near a normal, steady state

12. The Endocrine System
Made of glands that release chemicals called hormones into the bloodstream
Hormones will affect cellular activities by bonding to receptors of cells
Target cells receive specific hormones (like a lock and key)

13. Which system is most directly involved in the events represented in the diagram above?
(1) digestive
(2) endocrine
(3) nervous
(4) respiratory

14. Q: The diagram below represents an interaction between parts of an organism.
The term chemicals in this diagram represents
(1) starch molecules (2) DNA molecules
(3) hormone molecules (4) receptor molecules

15. Responding to hormones
Lock and key system
hormone fits receptor on “target” cell
target cell
secreting cell
non- target cells
can’t read signal
can’t read signal

16. Q:

17. Q: A characteristic of hormones and enzymes that allows them to work effectively with other organic molecules is their
(1) specific shape
(2) small size
(3) concentration of carbon and hydrogen atoms
(4) high-energy bonds

18. Glands Pineal (sweet sleep) Pituitary (master gland) Thyroid Adrenal
melatonin
Pituitary (master gland)
Contols many hormones:
Thyroid
thyroxine
Adrenal
Adrenaline (fight or flight response)
Pancreas
insulin, glucagon (regulate blood sugar)
Ovary
estrogen
Testes
testosterone

19. Maintaining homeostasis
Feedback
Maintaining homeostasis
hormone 1
gland
lowers body condition
high
specific body condition
low
raises body condition
gland
hormone 2

20. specific body condition
Negative Feedback
Response to changed body condition
if body is high or low from normal level
signal tells body to make changes that will bring body back to normal level
once body is back to normal level, signal is turned off
hormone 1
gland
lowers body condition
high
specific body condition

21. Regulation of Blood Sugar
Endocrine System Control
Feedback
Regulation of Blood Sugar
insulin
body cells take up sugar from blood
liver stores sugar
reduces appetite
pancreas
liver
high
blood sugar level
(90mg/100ml)
low
liver releases sugar
triggers hunger
pancreas
liver
glucagon

22. Apply Your Knowledge What are the effects of insulin and glucagon?
ANSWER: Insulin decreases blood glucose concentration and increases protein synthesis.
Glucagon does just the opposite. It increases blood glucose and decreases protein synthesis.
Yippee!

23. Q: The pancreas produces one hormone that lowers blood sugar level and another that increases blood sugar level. The interaction of these two hormones most directly helps humans to
(1) maintain a balanced internal environment
(2) digest needed substances for other body organs
(3) dispose of wastes formed in other body organs
(4) increase the rate of cellular communication

24. Insulin is a hormone that has an important role in the maintenance of homeostasis in humans.
Identify the structure in the human body that is the usual source of insulin.
__________________________________

25. Q: The most immediate response to a high level of blood sugar in a human is an increase in the
(1) muscle activity in the arms
(2) blood flow to the digestive tract
(3) activity of all cell organelles
(4) release of insulin

26. GONADS – sex glands Ovaries
Releases Estrogen – 2nd degree sex characteristics/ cycle
Releases Progesterone – cycle and maintain pregnancy
Testes
Releases Testosterone – 2nd degree male characteristics and
production of sperm

27. Pituitary gland hormones
Sex & reproductive hormones
FSH
follicle stimulating hormone
stimulates egg & sperm production LH
luteinizing hormone
stimulates ovaries & testes
prepares uterus for fertilized egg
Oxytocin (“love hormone”)
stimulates childbirth contractions
releases milk in nursing mothers
prolactin
milk production in nursing mothers
hormones
hormones

28. Reproductive hormones
Testosterone
from testes
sperm production & male secondary sexual characteristics
Estrogen
from ovaries
egg production, preparing uterus for fertilized egg & female secondary sexual characteristics

29. Egg maturation in ovary
releases progesterone
maintains uterus lining
produces estrogen

30. Menstrual cycle Controlled by interaction of 4 hormones FSH & LH
estrogen
progesterone
FSH
ovulation = egg release
egg development
corpus luteum
estrogen
progesterone
lining of uterus
days 7 14 21 28

31. Female reproductive cycle
Feedback
Female reproductive cycle
egg matures &
is released (ovulation)
builds up uterus lining
estrogen
ovary
corpus luteum
progesterone
FSH & LH
fertilized egg (zygote)
maintains uterus lining
HCG
yes
pituitary gland
corpus luteum
pregnancy
GnRH no
progesterone
corpus luteum breaks down
progesterone drops
menstruation
maintains uterus lining
hypothalamus

32. Female hormones FSH & LH Estrogen Progesterone released from pituitary
stimulates egg development & hormone release
peak release = release of egg (ovulation)
Estrogen
released from ovary cells around developing egg
stimulates growth of lining of uterus
decreasing levels causes menstruation
Progesterone
released from “corpus luteum” in ovaries
cells that used to take care of developing egg
stimulates blood supply to lining of uterus

33. Regulation by chemical messengers
Neurotransmitters released by neurons
Hormones release by endocrine glands
endocrine gland
neurotransmitter
axon
hormone carried by blood
receptor proteins
receptor proteins
target cell

34. Q: A similarity of the human nervous and endocrine systems is that both normally
(1) secrete chemical messengers
(2) have the same rate of response
(3) have the same duration of response
(4) secrete hormones that travel by way of neurons

35. Q: Communication between cells is affected if there is decreased ability to produce
(1) digestive enzymes and gametes
(2) antibodies and chloroplasts
(3) hormones and nerve impulses
(4) antibiotics and guard cells

36. Body Regulation Nervous system & Endocrine system work together
hypothalamus
“master nerve control center”
receives information from nerves around body about internal conditions
communicates with pituitary gland
“master gland”
releases many hormones
sexual development, growth, milk production, pain-relief
hormones

37. Nervous vs. Endocrine

38. Common Diseases and Disorders (cont.)
Disease/Disorder
Description
Gigantism
Too much growth hormone produced during childhood
Dwarfism
Too little growth hormone (somatotropin) produced during childhood
Grave’s disease
Hyperthyroidism; antibodies attach to thyroid gland, causing it to produce too much thyroid hormone
Goiter
Enlargement of thyroid gland, causing swelling in neck; deficiency of iodine in diet

39. Homework Complete the handout REMINDER:
Human disease project is due Jan. 10