Chemical Signals 2

Chemical Signals 2

BIOL 1407

Endocrine Glands

• Hormone-secreting cells make up endocrine system

• Ductless glands• Secrete into blood• Receptors on

target cells

Hypothalamus-Pituitary Axis

Hormones Released

from Posterior Pituitary

Relationship of Hypothalamus and Anterior

PituitaryHypothalamus

Levels of T3/T4 fall below minimum range

Receptor on Hypothalamic Neuron

Example: Control of Release of T3/T4

Thyroid Gland

• Calcitonin – Ca regulation

• T3 and T4

– Metabolic rate– Other effects:

• Nervous

• Reproductive

• Muscle

• Heart & blood pressure

• Digestive system

• Development• Diagram Credit: US Government, Wikimedia Commons

T3/T4: Tadpole Metamorphosis

Control of Ecdysis

• Ecdysis in Crustacean: http://www.youtube.com/watch?v=qACc82n6ODE

• Photo Credit: Macau500, 2004, Wikimedia Commons

Brain Hormone (BH) = PTTH

(Prothoracicotropic Hormone)

The End

Unless otherwise specified, all images in this presentation came from:

Campbell, et al. 2008. Biology, 8th ed. Pearson Benjamin Cummings.