Chapter 5: Hormones and Behavior Flashcards
1
Q
Do hormones have one effect on different systems, or a variety of effects?
A
Variety
2
Q
How do hormones affect the body?
A
In myriad ways.
3
Q
What system do hormones interact with the most?
A
The Nervous System
4
Q
Hormones
A
Chemicals secreted by one cell group, that travel through the bloodstream to act on targets.
5
Q
Endocrine Glands
A
Release Hormones within the body
6
Q
Exocrine Glands
A
Use ducts to secrete fluids such as tears and sweat outside the body
7
Q
What are the 6 forms of chemical communication?
A
- Synaptic
- Endocrine
- Autocrine
- Paracrine
- Pheromone
- Allomone
8
Q
Synaptic Communication
A
Involves chemical release and diffusion across a synapse
9
Q
Endocrine Communication
A
A hormone is release into the bloodstream to act on target tissues.
10
Q
Autocrine Communication
A
A released chemical acts on the releasing cell
11
Q
Paracrine Communication
A
The released chemical diffuses to nearby target cells
12
Q
Pheromone Communication
A
Hormones can be used to communicate between individuals of the same species
- Pheromones are released into the environment
13
Q
Allomone Communication
A
Allomones are chemicals released by one species to affect the behavior of another species
14
Q
What was the first major experiment on the endocrine system?
A
Arnold Berthold in 1800s
15
Q
What did Berthold’s experiment examine?
A
The role of testes in roosters
16
Q
Castration
A
Removal of the gonads (testes), resulting in behavioral and physiological changes.
17
Q
What was Bertholds major findings in his experiment?
A
Testes release a chemical into the bloodstream that affects male behavior and body structure.
18
Q
How did Berthold come to his findings?
A
He removed the testes of a rooster while it was young, and replaced the testes in adulthood.
19
Q
Did the replacement of the testes in the rooster allow it to develop normally?
A
No - The rooster did not restore back to normal size, functioning, or behavior.
20
Q
What did the replacement of the testes in the rooster indicate?
A
Hormones released by the testes must organize the body in a developmental manner.
21
Q
What are the 8 general principles of hormone actions?
A
- Hormones act in a gradual fashion.
- Hormones act by changing the probability/intensity of a behavior (do not switch on and off).
- The relationship between behavior and hormones is reciprocal (influence each other)
- A hormone may have multiple effects, and one behavior can be affected by several hormones.
- Hormones often have a pulsatile secretion pattern (it bursts).
- Some hormones are controlled by circadian clocks.
- Hormones can interact with other hormones and change their effects.
- Hormones can only affect cells with a receptor protein for their hormone.
22
Q
Neurons influence _______.
A
Hormone systems
23
Q
What can both neurotransmitters and hormone do?
A
Bind to receptors and activate second messengers, which bring about changed in cellular function.
24
Q
Neurosecretory Cells
A
Neurons that release hormones into the blood
25
What are Neurosecretory Cells crucial for?
Brain control of the hormone systems
26
What can some peptides serve as?
Neurotransmitters (neuropeptides) and hormones
27
What is the 1st difference of neural and hormonal communication?
- Neural communication travels to precise destinations.
- Hormonal communication spreads throughout the body and is picked up by cells with the proper receptor.
28
What is the 2nd difference of neural and hormonal communication?
- Neural messages are rapid
- Hormonal messages are slower
29
What is the 3rd difference of neural and hormonal communication?
- Neural messages travel short distance over the synaptic cleft.
- Hormonal messages may travel over a meter
30
What is the 4th difference of neural and hormonal communication?
- Neural messages are usually digital (all or none)
- Hormonal messages are analog (graded in strength)
31
What is the 5th difference of neural and hormonal communication?
- Neural communications are sometimes under voluntary control.
- Hormone messages are involuntary
32
What are the 3 major classes of hormones based on their structure?
1. Protein
2. Amine
3. Steroid
33
Protein Hormones
A string of amino acids
- called peptide hormones
34
Amine Hormone
Modified amino acids
- called monoamine hormones
35
Steroid Hormones
4 rings of carbon atoms
- based on a cholesterol backbone
36
How do hormones exert effects on cells and tissues in the body?
1. Promoting proliferation, growth, and differentiation of cells.
2. Modulating cell activity
37
What is the 1st way hormones produce their physiological effects?
Protein and amine hormones bind to specific receptors on the surface of a cell. Causes release of a second messenger in the cell.
38
What is the 2nd way hormones produce their physiological effects?
Steroid hormones pass through the cell membrane and bind to receptors inside the cell.
- Steroid receptor complex binds to DNA and acts as a transcription factor (control gene expression)
= genomic effects of the steroid hormones
39
Protein and amine hormones act ____.
Rapidly
40
What happens when protein and amine hormones bind to the extracellular part of a receptor?
The receptor changes shape and the intracellular part activates a second messenger.
41
Steroid hormones act ___.
Slowly
42
What happens when steroid receptor complexes form?
They alter protein production with long lasting effects.
43
What do some steroids act on?
More than one receptor (receptor isoforms) with functional differences.
44
Receptor Isoforms
More than one receptor
45
What is necessary for the cell to respond to the steroid receptor complexes?
Steroid receptor cofactors
46
What do different cells express?
Different cofactors
47
What does the expression of different cofactors lead to?
Different effects on the same steroid receptor complex depending on the cofactor present.
48
What steroid has a non genomic effect?
Estradiol
49
Non Genomic Effect
A rapid, brief effect involving neuronal membrane receptors
50
What is an example of a non genomic effect?
Testosterone has rapid effects on receptors located in axons and other sites distant from the nucleus.
51
Sometimes the brain...
1. Breaks down its own steroids
2. Transforms one steroid into another
52
How is the release of hormones controlled?
Feedback systems
53
Negative Feedback
Output feeds back and inhibits further secretion.
54
Autocrine Response
An endocrine gland releasing hormone and feeding it back onto itself
55
Target Cell Feedback
The hormone acts on its target cells and had a biological effect
56
Biological Effect
Detected by the endocrine gland and inhibits further release
57
What do more complex endocrine systems involve?
Brain (usually hypothalamus)
58
Hypothalamus
Can direct hormone release
- The brain detects the hormone's effects and exerts negative feedback onto the hypothalamus
59
What is the anterior pituitary gland involved with?
1. Tropic Hormones
2. Releasing Hormones
60
Tropic Hormones
Pituitary hormones that affect other endocrine glands
61
Releasing Hormones
Used by the hypothalamus to control the pituitary release of tropic hormones.
62
What are the 2 parts of the pituitary gland (hypophysis)?
1. Anterior Pituitary
2. Posterior Pituitary
63
The two parts of the pituitary are thought of as _____ _____.
Separate structures
64
Pituitary Stalk (infundibulum)
Connects the pituitary to the hypothalamus
65
What does the stalk contain?
Blood vessels and many axons (only extend to the posterior pituitary)
66
What two hormones does the posterior pituitary secrete?
1. Oxytocin
2. Vasopressin or Arginine Vasopressin (AVP)
67
Oxytocin
Involved in reproductive and parenting behavior
- also in uterine contraction and milk letdown reflex
68
Milk Letdown Reflex
Sucking stimulates a reflex which produces the milk
69
AVP / Vasopressin
Increases blood pressure and inhibits urine formation
70
What do vasopressin and oxytocin serve as?
Neurotransmitters in the hypothalamus
71
Hypothalamic Neurons
Synthesize releasing hormones
72
Median Eminence
Where the axons from releasing hormones converge
- Above the pituitary stalk
73
What are releasing hormones secreted into?
Local blood vessels called the hypophyseal portal system
74
What is released when the releasing hormones are carried into the anterior pituitary?
Tropic hormones
75
What is the hypothalamus influenced by?
1. Circulating messages (other hormones)
2. Synaptic inputs from other brain areas
76
What 6 tropic hormones does the anterior pituitary release?
1. Adrenocorticotropic (ACTH)
2. Thyroid Stimulating (TSH)
3. Follicle Stimulating (FSH)
4. Luteinizing (LH)
5. Prolactin
6. Growth (GH)
77
Adrenocorticotropic Hormone (ACTH)
Controls adrenal cortex and its steroid hormone release
78
Thyroid Stimulating Hormone (TSH)
Increases thyroid hormone release
79
Gonadotropins
Influence the gonads (testes)
80
Follicle Stimulating Hormone (FSH)
Stimulates egg containing follicles or sperm production
81
Luteinizing Hormone (LH)
-Stimulates the follicles to form the corpora lutea
- Promotes testosterone release
82
What 2 tropic hormones are gonadotropins?
1. Follicle Stimulating Hormone
2. Luteinizing Hormone
83
Prolactin
Stimulates lactation in females and is involved in parental behavior
84
Growth Hormone (GH)
Influences growth mostly during sleep.
85
What other hormone also evokes Growth Hormone release?
Ghrelin (stomach hormone)
86
What can alterations in hormone systems produce?
Profound effects on the individual
87
What is an example of an alteration in the hormone system?
Stress
88
Psychosocial Dwarfism
A failure to grow caused by stress in early life
89
Somatomedins
Hormones that normally aid growth
90
What are somatomedins released by?
The liver in response to growth hormones
91
What can interfere with growth hormone release?
1. Stress
2. Sleep deprivation
= negative effects on normal growth
92
Who normally shows psychosocial dwarfism?
Children growing up in severely abusive/stressful households
93
What does psychosocial dwarfism illustrate?
Interactions between "environment" and basic body functioning
94
Adrenal Glands
Located at the top of each kidney and secrete hormones
95
Adrenal Gland in mammals
Outer 80%
96
Adrenal Medulla in mammals
Core 20%
97
What two amine hormones does the Adrenal Medulla release?
1. Epinephrine (adrenaline)
2. Norepinephrine (non-adrenaline)
98
What are epinephrine and norepinephrine controlled by?
The sympathetic NS
99
Adrenocorticoids
Steroid hormones secreted by the adrenal cortex
100
Glucocorticoids
A subgroup involved with glucose metabolism
101
Cortisol
A glucocorticoid stress hormone that increases blood glucose and breaks down protein
102
HPA Axis
The system from the hypothalamus -> anterior pituitary -> adrenal gland
103
Mineralcorticoids
Adrenal steroids that affect ion concentrations in tissues
104
What is an example of a mineralocorticoid?
Aldosterone
105
Aldosterone
Acts on the kidneys to retain sodium
106
Sex Steroids
Steroid hormones produced in the adrenal cortex
107
What is an example of a sex steroid?
Androstenedione
108
Androstenedione
Affects patterns of body hair in men and women
109
What do the thyroid gland produce?
Thyroid hormones
110
What is the thyroid stimulating hormone (TSH) secreted by?
The pituitary gland
111
What is the release of thyroid stimulating hormone (TSH) controlled by?
1. Negative feedback from blood levels
2. Thyrotropin releasing hormone (TRH) from the hypothalamus
112
Thyrotropin Releasing Hormone (TRH)
Located in the hypothalamus and controls TSH
113
Thyroid Hormones
General effects on growth and basic nervous system functioning
114
What do thyroid hormones contain?
Iodine - dependent on its supply
115
Goiter
A swelling of the thyroid gland resulting from iodine deficiency
116
What can early thyroid deficiency result in?
1. Congenital Hypothyroidism
2. Cognitive impairments
117
Gonads
Ovaries and testes
- produce sex steroids
118
Gonadotropin Releasing Hormone (GnRH)
Released by the hypothalamus to control gonadal hormone production.
119
What does GnRH stimluate?
The anterior pituitary
- releases Follicle Stimulating Hormone (FSH) or Luteinizing Hormone (LH)
120
Kisspeptin
A hypothalamic peptide that stimulates GnRH
- involved in the onset of puberty
121
Gonadotropin Inhibiting Hormone (GnIH)
Released by the hypothalamus to inhibit gonadotropic secretion
122
What do testes produce?
Testosterone
123
Androgens
Male hormones
124
What is an example of an andorgen?
Testosterone
125
What does Gonadotropin Releasing Hormone (GnRH) regulate?
Luteinizing Hormone -> regulates testosterone
126
Ovaries
Produce hormones in cycles, called progestins
127
What is an example of a progestin?
Progesterone
128
What are example of estrogens?
1. 17B Estradiol
2. Estradiol
129
What controls ovarian hormone release?
1. Luteinizing Hormone (LH)
2.Follicle Stimulating Hormone (FSH)
- Those are both controlled by GnRH
130
Oral Contraceptives
Contain synthetic steroids that inhibit the release of GnRH
131
What occurs when there is a lack of GnRH?
- Prevents the release of FSH and LH
= No egg is released by the ovary
132
Pineal Gland
A single gland on top of the brainstem
133
What does the pineal gland secrete?
Melatonin (amine hormone)
- almost exclusively at night
134
Melatonin
Provides a signal that tracks day length and the seasons
135
How does oxytocin play a role in social behavior?
Oxytocin is released during nursing interaction and orgasm
- promotes pair bonds in prairie voles
136
How does vasopressin play a role in social behavior?
In male prairie voles, it facilitates the formation of pair-bonds with females.
137
Prairie Voles are _____.
Monogamous
138
Meadow Voles are ____.
Not monogamous
139
Monogamous
One sexual relationship to one parter at a given time.
140
What does endocrine pathology resemble?
Psychiatric Disorders
141
What is are 2 examples of endocrine pathology resembling a psychiatric disorder?
1. One type of ADHD involves decreased sensitivity to thyroid hormone
2. Cushing's Disease results from long term excess of glucorticoids, with symptoms of fatigue and depression.
142
What are the 4 ways the hormonal and neural system communicate?
1. Neural to neural
2. Neural to endocrine
3. Endocrine to endocrine
4. Endocrine to neural
143
What does experience affect?
Hormone secretion, which affects behavior, which affects future experiences
