Ch 45 pt 1 Flashcards
(31 cards)
Chemical Signaling by hormones
Endocrine system
Endo
within
Crine
secrete
What is the Nervous system?
Network of specialized cells-neurons- that transmit signals along dedicated pathways
Animals use ___ to communicate in diverse ways
Chemical signals
Where do endocrine cells secrete hormones into?
Extracellular fluids
What system picks up the hormones
Circulatory system
What are Local Regulators?
Molecules that act over short distances reaching target cells by diffusion
What happens in Paracrine signaling?
Target cells lie near the secreting cells
What happens in Autocrine signaling?
Target cell is also the secreting cell
Para
Along side
Auto
Self
What are Prostaglandins?
Local Regulators that mediate signaling in paracrine and autocrine signaling
Function in the immune system and blood clotting
What is Synaptic Signaling?
Neurons form specialized junctions with target cells called synapses
What are Neurotransmitters?
At synapses, secreted molecules that diffuse short distances and bind to receptors on target cells
What are neurohormones? (2)
1) Secreted by neurosecretory cells
2) diffuse from nerve endings into the bloodstream
Neuroendocrine signaling
Neurosecretory cells secrete neurohormones that diffuse from nerve endings into bloodstream
How do some animals species communicate
Pheromones, chemicals that are released into the environment
Pheromones uses (4)
1) Marking trails to food
2) Defining territories
3) Warning of predators
4) Attracting potential mates
Local Regulators such as Prostaglandins are modified _______
fatty acids
What are the 3 classes of local regulators?
1) prostaglandins
2) polypeptides
3) gases
traits of Nitric Oxide (2)
1) Gas that function as both a local regulator and neurotransmitter
2) When O2 in blood falls, NO activates enzyme that results in vasodilation
Hormones 3 major classes
1) Polypeptides (water soluble)
2) Steroids (lipid soluble)
3) Amines (water soluble)
characteristics of Water soluble hormones (3)
1) Secreted by exocytosis
2) Travel freely in the bloodstream
3) Bind to cell surface receptors