Endocrine system Flashcards
Coordination of biological systems requires _________.
Cell communication. Nervous system and endocrine system are VERY intertwined!
Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testes, along with distant cells outside the gonads. Thus, testosterone is an example of
A) an autocrine signal.
B) a paracrine signal.
C) an endocrine signal.
D) an autocrine signal, a paracrine signal, and an endocrine signal
D - an autocrine (itself), paracrine (cells near it), and endocrine signal (cells far away)
What are water-soluble hormones (hydrophillic)? How are they transported?
Polypeptide (protein) made hormones.
Secreted from the cell, circulates in bloodstream, received at receptor on targeted cell
What are lipid-soluble hormones (hydrophobic)? How are they transported?
Fat made hormones.
Secreted from cell, circulates in bloodstream w/ transport protein, goes to receptor cells inside of the nucleus of target cell
What are amines?
Hormones that have nitrogen in them (amino group)
Some are hydrophilic and some are hydrophobic
What are two of the different effects a single hormone can have on target cells?
Different receptors for the hormone that trigger different transduction pathways
Same receptors for the hormone, but different signal transduction pathways (different relay molecules)
What effects does epinephrine (adrenaline) have on liver cells, smooth muscle cells (skeletal), and smooth muscle cells (intestinal)?
Liver cells - glycogen breaks down and glucose is released
Smooth muscle (skeletal) - changes to relaxed state, allows dilation of blood vessels
Smooth muscle (intestinal) - changes to contracted state - decreases blood flow to the intestines
What does negative feedback do?
It inhibits a response by reducing the initial stimulus. Gets rid of stimulus. Ex. Secretin in digestive system
What does positive feedback do?
It reinforces a stimulus to produce an even greater response. Increases stimulus. Ex. Oxytocin (labor)
An example of antagonistic hormones controlling
homeostasis via negative feedback is
A) oxytocin and prolactin in milk production.
B) insulin and glucagon in glucose metabolism.
C) thermostat controlling the temperature in a room.
D) pheromonal attraction
B (eliminating deviation from a set point)
What are the three parts of the H-P-E/T/A system?
The hypothalamus, the pituitary gland, and the endocrine glands (gonads, thyroid, or adrenal)
What does the hypothalamus do? What does it secrete?
The hypothalamus receives information from the nervous system and secretes releasing hormones
What does the pituitary gland do (overall)? What does it secrete?
It receives releasing hormones from the hypothalamus, and secretes trophic hormones
What does the posterior pituitary gland release?
ADH (goes to kidney tubules)
Oxytocin (goes to mammary glands/uterine muscles)
NOT trophic hormones!
What are trophic hormones?
Hormones that cause other endocrine glands (gonads, thyroid, adrenal glands) to release a hormone
