1. Endocrine Glands

2. Chemical Messengers Autocrine Paracrine Endocrine Pheromone Allomone
self signal
Paracrine
neighbor signal
Endocrine
distant signal
Pheromone
airborne signal
same species
Allomone
different species

3. Hormone Types

4. Homeostasis Mechanism
Receptors
input signals
skin responds to cold
temperature
sends signal to brain
Control Center
integrating center
brain interprets temp signal
makes you shiver
Effectors
output mechanism
muscles shiver creating heat

5. Negative Feedback Results in an immediate reversal
of the imbalanced system
Immediately negates the
disruption
Most systems in the body work
via negative feedback systems
temperature
glucose balance
water balance
blood pressure

6. Positive Feedback Immediate further disruption of the
imbalance so as to later return to
homeostasis
childbirth
ovulation

7. Positive Feedback: Childbirth

8. Neuroendocrine Reflex
Baby suckling stimulates receptors on the nipple
Action potential travels to the hypothalamus
Hypothalamus sends oxytocin to posterior pituitary gland
Posterior pituitary releases oxytocin into the blood stream
Oxytocin travels to the breast and triggers milk release

9. Posterior Pituitary Hormones synthesized in the hypothalamus
Released by the posterior pituitary
Oxytocin
milk ejection
orgasm
Vasopressin or ADH
water balance
blood pressure

10. Anterior Pituitary Releasing hormones synthesized in the hypothalamus
CRF/CRH
GnRH
GHRH
TRH
PRH
Triggers hormone release in
anterior pituitary
ACTH
LH/FSH GH
TSH
PRL

11. The Stress Continuum

12. Stress
The process by which we perceive and respond to certain events, called stressors, that we appraise as threatening or challenging

13. HPA Axis
Hypothalamus
CRF/CRH
Pituitary
ACTH
Adrenals
Cortisol

14. Stress and Hormone Release

15. Stress Diathesis Model
Existing Correlations:
Adult Depression : Elevated Cortisol levels
Childhood Abuse : Adult Depression
Stress Diathesis Model:
Genetic Predisposition plus
Early Abuse/Neglect leads to
Adult Depression
Animal Model shows:
More CRF neurons
Larger CRF neurons
More sensitive CRF neurons
Early abuse permanently alters the stress
response increasing the risk of depression

16. General Adaptation Syndrome
(GAS)
1. Alarm Reaction
2. Resistance Reaction
3. Exhaustion