LECTURE 3: CHEMICAL SIGNALS IN ANIMALS Flashcards
Regulatory Mechanisms
- Nervous System
- Endocrine System
conveys high-speed
electrical signals along specialized cells
called neurons; these signals regulate
other cells
nervous system
secretes hormones
that coordinate slower but longer-acting
responses including reproduction,
development, energy metabolism, growth,
and behavior
endocrine system
____________ are chemical
signals that are secreted into the
circulatory system and communicate
regulatory messages within the body
Animal hormones
*Hormones reach all parts of the body,
but only __________ are equipped to
respond
target cells
ex: ________________ is regulated by
hormones
Insect metamorphosis
Two type of Glands in Vertebrate Endocrine System
- Exocrine Gland
- Endocrine Glands
- secrete chemicals into ducts and the
effect is where the duct empties; sweat glands - sweat(evaporative cooling)
Exocrine glands
secrete chemical messengers
(hormones) into the blood for distribution throughout the
animal’s body and bind to specific hormone receptors.
Endocrine glands
- Hormones and other signaling molecules bind to
target receptors, triggering specific response pathways - Chemical signals bind to receptor proteins on target
cells - Only target cells respond to the signal
Target Cell Concept
Hormones and other signaling molecules bind to ____________, triggering specific response pathways
target receptors
Two Factors influencing the hormone concentration in the blood
1, Rate of Hormone Secretion into the blood
2. Rate of Removal of the hormone from the blood (metabolic clearance rate)
Clearance of Hormones from the plasma include:
- Metabolic Destruction
- Binding with the tissue
- excretion by the liver into the bile
- excretion by the kidney into the urine
Refers to the duration of time required to decrease the concentration of a circulating hormones by half
Half life of a hormones
Chemical Messengers
Hormones
Intercellular Communication
- Endocrine Signaling
- Synaptic Signaling
secreted molecules diffuse into the bloodstream and trigger responses in target cells anywhere in the body
Endocrine signaling
Types of Endocrine Signaling
- Paracrine Signaling
- Autocrine Signaling
secreted molecules
diffuse locally and trigger a response in
neighboring cells
Paracrine signaling
secreted molecules
diffuse locally and trigger a response in
the cells that secrete them
Autocrine signaling
neurotransmitters
diffuse across synapses and trigger
responses in cells of target tissues
Synaptic signaling
neurohormones diffuse into the
bloodstream and trigger responses
Neuroendocrrine signaling