Chapter 45 Flashcards
What body system is in charge of chemical signaling by hormones?
Endocrine system
What body system is a network of specialized cells called neurons that transmit signals along pathways?
Nervous system
What 3 things determine how signals are transmitted between animal cells?
1) type of secreting cell
2) route taken by the signal in reaching its target
3) type of receptor involved
Molecules that act over short distances, reaching target cells by diffusion
Local regulators
Target cells lie near secreting cells
Paracrine signaling
Target cell is also the secreting cell
Autocrine signaling
Local regulators that mediate paracrine and autocrine signaling. They help with reproduction, the immune system, and blood clotting
Prostaglandins
Chemicals that are released into the environment. They mark trails that lead to food, define territories, warn of predators, and attract mates
Pheromones
How are water-soluble hormones secreted?
By exocytosis
What are the 2 types of corticosteroids that humans produce?
1) glucocorticoids
2) mineralocorticoids
What are the 2 criteria that determine the ways signals are transmitted between animal cells
1) type of secreting cell
2) route taken by the signal in reaching its target
Molecules that act over short distances, reaching target cells solely by diffusion
Local regulators
What processes do paracrine and autocrine signaling play big roles in?
Blood pressure regulation, nervous system function, reproduction
At synapses, neurons secrete molecules that diffuse short distances and bind to receptors on target cells. What are these molecules called?
Neurotransmitters
A gas that functions in the body as both a local regulators and a neurotransmitter
Nitric oxide (NO)
Name the 3 classes of hormones (chemical classes)
Polypeptides
Steroids
Amines
What is the difference between steroids and polypeptides?
Polypeptides are water-soluble; steroid hormones are lipid-soluble
Give an example of a hormone that may have different effects on target cells
Epinephrine-can increase blood flow to major skeletal muscles, but decreases blood flow to the digestive tract
___ reach all parts of the body, but only ___ cells have receptors for that hormone
Hormones
Target
Chemical signaling by hormones is the function of which system?
Endocrine
Which type of feedback results in reinforcing a stimulus to produce an even greater response?
Positive feedback
___ do not have have ducts; ___ glands do have ducts
Endocrine
Exocrine
What is the function of melatonin? Which gland secretes it?
Melatonin regulates sleep; the pineal gland secretes melatonin
Stops a gland from secreting a hormone
Negative feedback
Increases stimuli, which causes more hormones to be secreted
Positive feedback
What does the antidiuretic hormone (ADH) regulate?
Physiology and behavior
When the thyroid gland produces too small of an amount of TSH, which causes weight gain and cold intolerance
Hypothyroidism
Which gland secretes growth hormone (GH)?
Anterior pituitary
Composed of posterior and anterior pituitary
Pituitary gland
In neuroendocrine signaling,specialized ___ cells secrete molecules called neurotransmitters that travel to target cells via the bloodstream
Neurohormones
Endocrine cells are often grouped in ductless organs called __ glands such as the thyroid and parathyroid glands, testes, and ovaries
Endocrine glands
Binding of a hormone to its receptor initiates a ____ ____ ____ leading to responses in the cytoskeleton, enzyme activation, or a change in gene expression
Signal transduction pathway
Insulin and glucagon are secreted by the ___
Pancreas
Secretes a neurohormone which enters the bloodstream and travels to target cells
Neurosecretory cell
Inhibits a response by reducing the initial stimulus, thud preventing excessive pathway activity
Negative feedback loop
Stores and secretes hormones that are made in the hypothalamus
Posterior pituitary
Makes and releases hormones under regulation of the hypothalamus
Anterior pituitary
Type of hormone that flows freely in the bloodstream and binds to cell surface receptors
Hydrophilic hormone
Type of hormone that diffuses across the cell membrane and travels to the bloodstream bound to transport proteins
Hydrophobic hormone
Regulates anterior pituitary; receives information from nervous system; initiates response through endocrine system.
Hypothalamus
Releases PTH to regular season blood calcium level
Parathyroid
Which responds faster, hormones or neurons?
Neurons
How do synapses send signals?
Neurotransmitters from one neuron are secreted and bind to target cells on another neuron
Name some endocrine glands
Hypothalamus, pituitary gland, thyroid gland, parathyroid gland, adrenal glands, pancreas, ovaries, testes
T or F: males and females both produce estrogen
True
Chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body
Animal hormones
Diffuse short distances and bind to receptors on target cells. Also give an example
Neurotransmitters. Example = nitric oxide
Travel to target cells via the bloodstream
Neurohormones
The hormone ___ has effects in mediating the body’s response to short-term stress
Epinephrine
Nerves from the hypothalamus trigger the release of ___ from the posterior pituitary
Oxytocin (cuddle hormone; causes mammary glands to secrete milk)
What two glands does the adrenal gland consist of?
Adrenal medulla (inner portion) Adrenal cortex (outer portion)
When cutting your finger, you feel a sharp pain due to ___
Prostaglandins
Name some types of local regulators
Cytokines, growth factors, polypeptides, gases
What is the role of the thyroid and parathyroid hormones?
Regulates the level of blood calcium to stabilization
What are the 3 types of sex hormones?
Androgens, estrogens, and progestins
Give examples of lipid solvable hormones
Thyroxine, vitamin D, steroids
Give examples of water soluble hormones
Epinephrine, insulin
T or F: neurotransmitters are secreted for short distances to bind target cells
True
Change the salt and water balance
Mineralocorticoids
Polypeptides and amines are ___ whereas steroid hormones and other largely nonpolar hormones are ___
Water-soluble; lipid-soluble
What happens when thyroid hormone level drops in the blood?
Hypothalamus secreted TRH (thyrotropin-releasing hormone) causing the anterior pituitary to secrete thyroid-stimulating hormone (TSH)
