Chapter 45: Hormones and the Endocrine System Flashcards
(43 cards)
1
Q
Hormones
A
- Signaling molecules
- Communicate regulatory messages throughout the body (pass through the bloodstream)
2
Q
Endocrine System
A
- 1 of 2 basic systems for communication and regulation (in the animal body)
- Chemical signaling = function
- Slow
3
Q
Nervous System
A
- 1 of 2 basic systems for communication and regulation (in the animal body)
- Network of specialized cells that transmit signals along dedicated pathways (regulate endocrine cells, muscle cells, and neurons)
4
Q
Local Regulators
A
- Molecules that act over a short distance
- Reach their target through diffusion
5
Q
Paracrine
A
Target cells lie near the secreting cells
6
Q
Autocrine
A
Secreting cells are the target cells
7
Q
Prostaglandin
A
- Local regulator
- Mediates signaling
- Acts in reproductive organs and in the immune system
- Helps regulate aggregation of platelets
- A modified fatty acid
8
Q
Neurotransmitters
A
- Diffuse at a very short distance
- Bind to receptors on target cells
9
Q
Neurohormone
A
- Molecule that is secreted by a neuron
- Travels in body fluids
- Acts on specific target cells, changing their functioning
10
Q
Pheromones
A
- Chemicals released externally into the environment
- Functions:
- defining territories
- warning of predators
- attracting potential mates
11
Q
Nitric Oxide (NO)
A
- Functions as a neurotransmitter and local regulator
- Released when blood oxygen levels fall
- Activates enzyme to relax cells, increasing blood flow to tissues
12
Q
Signal Transduction
A
- Series of changes in cellular proteins
- Changes the extracellular chemical signal to an intracellular response
13
Q
Epinephrine
A
- Adrenaline
- Causes cAMP to be synthesized and activation can cause glycogen breakdown
- Glucose is released into the bloodstream to fuel the fight/flight response
- A catecholamine
- Secreted by the adrenal medulla
14
Q
Endocrine Glands
A
- Ductless organs made up of endocrine cells
- Release hormones directly into surrounding fluid
15
Q
Oxytocin
A
- Hormone released by posterior pituitary
- Signals milk production in mammary glands
- Stimulates contraction of smooth muscle cells in uterus
16
Q
Negative Feedback
A
- Response reduces initial stimulus
- Helps restore to standing prior to stimulus
- Like an on/off switch
17
Q
Positive Feedback
A
- Response causes reinforcement of stimuli
- Continued response
18
Q
Hypothalamus
A
- Region of the brain
- Coordinates endocrine signaling in vertebrates
19
Q
Pituitary Gland
A
- Located at the base of the hypothalamus
- Receives signals from that gland
- Master gland
20
Q
Posterior Pituitary
A
- Extension of the actions of the hypothalamus
- Releases oxytocin and vasopressin (antidiuretic hormone)
21
Q
Anterior Pituitary
A
Synthesizes and secretes hormones in response to hypothalamus ones
22
Q
Antidiuretic Hormone (ADH)
A
- Functions in regulating the kidneys
- Also called vasopressin
- Secreted by the posterior pituitary
- Role in social behavior
23
Q
Prolactin
A
- Hormone produced and secreted by the anterior pituitary
- Diversity of effects in different vertebrate species
- Stimulates growth and milk production by the mammary glands in mammals
24
Q
Tropic Hormones/Tropins
A
Anterior pituitary hormones in a hormone cascade pathway
25
Thyroid Hormone
- Regulates bioenergetics
| - Helps maintain blood pressure, heart rate, muscle tone, and digestive/reproductive functions
26
Growth Hormone (GH)
- Secreted by anterior pituitary
| - Stimulation causes tropic/nontropic effects to cause growth
27
Parathyroid Glands
- 4 small endocrine glands
- Embedded in the surface of the thyroid
- Secretes parathyroid hormone
28
Parathyroid Hormone (PTH)
- Increases level of blood Ca2+
- Causes mineralized matrix of bones to break down
- Stimulates reabsorption of Ca2+ in renal tubules of kidneys
- Promotes production of Vitamin D (indirect effect on intestines)
29
Calcitonin
- Inhibits bone breakdown
- Enhances Ca2+ excretion by kidneys
- Secreted by the thyroid gland
30
Adrenal Glands
- Located near the top of the kidneys
- Made up of the adrenal cortex (outer) and adrenal medulla (central)
- Fused endocrine and neurocrine gland
31
Norepinephrine
- Noradrenaline
- A catecholamine
- Secreted by the adrenal medulla
- Chemically and functionally similar to epinephrine
- Acts as a hormone or neurotransmitter
- with epinephrine, responsible for the fight/flight response
32
Catecholamines
Amine hormones synthesized from the amino acid tyrosine
33
Glucocorticoids
- Have a primary effect on glucose metabolism
- Cause breakdown of skeletal muscle proteins (when reserves run out in the liver)
- Can have an anti-inflammatory effect
34
Mineralocorticoids
- Have an effect on mineral metabolism
| - Specifically affect water and salt balance
35
Androgens
- Example: testosterone
- Responsible for the development of male secondary sex characteristics
- Primarily synthesized by the testes
36
Testosterone
- Steroid hormone
- Required for development of the male reproductive system, spermatogenesis, and male secondary sex characteristics
- Major androgen in mammals
37
Estrogens
- Example: estradiol
- Maintain female reproductive system
- Develop female secondary sex characteristics
38
Estradiol
- Steroid hormone
- Stimulates the development and maintenance of the female reproductive system and secondary sex characteristics
- Major estrogen in mammals
39
Progestins
- Example: progesterone
| - Prepare and maintain tissues lining the uterus for the support and development of an embryo
40
Progesterone
- Steroid hormone
- Prepares the uterus for pregnancy
- Major progestin in mammals
41
Melatonin
-Modified amino acid
-Regulates light and seasonal related functions
-Functions in:
-skin pigmentation
-biological rhytyms associated with reproduction and daily
activity
-promoting sleep
42
Pineal Gland
- Small mass of tissue near the brain
| - Produces melatonin
43
Melanocyte-Stimulating Hormone (MSH)
- Secreted by anterior pituitary
- In amphibians, fish, and reptiles: it regulates pigmentation
- In mammals: functions in hunger, metabolism, and skin pigmentation
