Midterm Flashcards
(82 cards)
1
Q
What are the major endocrine glands?
A
hypothalamus, pituitary, thyroid, adrenal, pancreas, gut, gonads
2
Q
Where do hormones come from?
A
they are secreted through the endocrine glands
- glands tend to secrete specific hormones
- precursor to vertebrate hormones: cholesterol
3
Q
Where do hormones go?
A
hormones travel throughout the blood stream - can affect any part of the body
- target specific receptors in the tissue/cells
- no specificity in where it is sent, so receptor location important
4
Q
What are some short term effects of hormones?
A
short term effects
- change membrane potential, affect action potentials
- change protein expression
long
5
Q
what are some long term effects of hormones?
A
- activate gene expression
- slower, but can coordinate throughout the organism (think puberty)
6
Q
What is the relationship between hormones and behavior?
A
bidirectionality
- hormones can affect behavior
- behavior can affect hormones
7
Q
What is the limbic system? What is its relationship to the hypothalamus?
A
the limbic system are higher brain areas that try to influence the hypothalamus
8
Q
Why is the time of castration important?
A
if it is before puberty, you can see physical effects.
- no facial hair, long arms, higher pitched voice, no sex drive
if it is after puberty, there is no effect on physical appearance
9
Q
What were the three conclusions of the Berthold chick experiment?
A
- testes are transferable
- no specific nerves control secretory function
- effects are only seen when castrated prepubescently
10
Q
How can you establish a relationship between hormones and behavior?
A
- removal of hormone removes behavior
- reintroducing hormone reintroduces behavior
- hormone concentration and behavior covaries
11
Q
What are proximate causation of behavior?
A
immediate causation
- change in [hormone]
developmental
learned behavior
12
Q
What are ultimate causation of behavior?
A
evolution
- what has been naturally selected
adaptive function
- what helps them spread offspring
13
Q
What did the soccer match experiment show?
A
behaviors can affect hormone levels
- increased levels of cortisol
- increased levels of T in men
14
Q
What are the two types of chemical agents that can alter the function of a hormone?
A
agonist - mimics the hormone
antagonist - blocks the effect of the hormone
15
Q
What are immunoassays
A
a technique that uses antibodies and competitive binding to tell us the hormone concentration
16
Q
What can immunochemistry tell us
A
what part of the body releases the hormone
what part of the body has receptors for that hormone
17
Q
What can autoradiography tell us?
A
by radiolabeling the hormone, it can tell us where the hormone and its receptors are within the body
18
Q
What can in situ hybridization tell us?
A
by searching for tissues with mRNA that codes for specific proteins, it can tell us where the hormone is being produced and how much of it
19
Q
What can anterograde track tracing tell us?
A
by injecting the tracker into the soma of the neuron, you can find the axonal projections
20
Q
What can retrograde tract tracing tell us?
A
by injecting the tracker into the projections, you can find the soma
21
Q
How does knockout genetics work?
A
you can get the knockout of a certain gene by manipulating the DNA
- mutate DNA in stem cells
- put it into blastocyst of one mouse and take the embryo
- gives birth to recessive chimeric babies
- have chimeric babies have babies
- some of the offspring will have total knockout of the gene
22
Q
What did knocking out of the alpha ERKO gene do?
A
produced female offspring with underdeveloped mammary ductal network and uterus
23
Q
How does optogenetics work?
A
by using knockout genetics, you can change their genes to react to specific wavelengths of light
- can stimulate or block action potentials
24
Q
What is intracrine mediation?
A
hormones in the cell regulate intracellular events
- the hormone remains in the cell
25
What is autocrine mediation?
the hormone released by the cell also binds to receptors to influence function of the same cell
26
What is paracrine mediation?
the hormone released by the cell effects cells adjacent to them
27
What is endocrine mediation?
hormones are released into the blood stream and can go to any part of the body
28
What is ectocrine mediation?
chemicals are released from the body and into the environment
- think of pheromones
29
Why is the hypothalamus so important for the endocrine system?
acts as the interface between brain and endocrine system
- work together to control and regulate the other endocrine glands in the body
- hypothalamus receives input from many higher brain regions
30
What does the anterior pituitary have that the PP doesn't?
has a portal that connects the hypothalamus to it
- closed blood circuits between hypothalamus and pituitary
- hormones are released from axons into the portal
releases trophic hormones into blood stream
31
What does the posterior pituitary have that the AP doesn't?
axons project directly onto the posterior pituitary
- this makes release much faster than AP
- releases vassopressin and oxytocin
32
Describe peptide hormones
```
made from proteins
largest class of hormones
do not need carriers, water soluble
structurally different across species
hypothalamic and pituitary hormones
released by exocytosis
```
33
Describe steroid hormones
```
all made from the precursor cholesterol
not soluble in water, require vesicles to travel within the blood
small, can diffuse through membranes
intracellular and membrane receptors
adrenal, gonads, brain
```
34
What governs [steroid hormone] in blood?
rate of synthesis
rate of inactivation/catabolism
affinity for binding to receptor
35
How are steroid hormones regulated?
they are never stored, once they are synthesized they are released
regulated by the enzymes that convert cholesterol into hormones
36
What is a prohormone?
a hormone that can act by itself or can continue to be synthesized into another hormone
37
What are androgens important for?
```
male secondary sexual development
spermatogenesis
muscle mass
courtship behavior
aggression
```
38
What do androgens do in women?
in the ovaries, there is an enzyme that converts androgens into estrogen
- rate depends on amount of enzyme available
39
What do estrogens do in women?
```
female secondary sexual development
stimulates formation of corpora lutea
bone mass
metabolism
sexual behavior
has a role in almost all tirrues
```
40
What is the difference between the hormones found in males and females?
have the same hormones, just the relative concentration of each is different
- driven by the different enzymes present in the organism
41
What are neurosteroids
steroid hormones produced by the brain
- produced by CNS glial cells from cholesterol
- modulates NT receptors
- synthesis independent of synthesis of other steroid hormones in peripheral glands
42
Where are steroid hormone receptors usually located?
intracellular: within the cytosol or the nucleus
| - complex with the hormone can stimulate gene transcription
43
What are the 3 domains of a hormone receptor?
1. c domain: binds to the hormone
2. center domain: where the hormone-receptor complex binds to the DNA - SPECIFIC
3, N domain: where DNA binding proteins can attach to
44
Why do we believe there are non-genomic actions of steroids?
```
there are some effects of steroid hormones that are much faster than genomic
can include:
modulating ion channels
interacting with NTs
membrane receptors
```
45
What evidence proves that there are non-genomic effects of steroid hormones?
injection of estradiol has immediate effects on action potential firing rates
10 min vs 30
46
How are hormones regulated?
positive feedback loop - stimulates hormone production
| negative feedback loop - slows/stops hormone production
47
What are the two types of hormone regulation of receptors?
homospecific priming: regulation of the receptors of the same hormone
heterospecific priming: regulation of the receptors of other hormones
48
What's the structure of a peptide hormone like?
region that spans the membrane
place to bind outside cell
region inside the cell
- can cause signaling cascade
49
What are the two types of signaling that peptide hormone receptors do?
intrinsic enzyme activity
- when hormone binds to the receptor, it changes the shape of the enzyme and allows for interaction with another protein and ATP, changes cell f(x)
secondary messenger
- when the hormone binds, it has a cascade that activates a messenger.
- messenger activates effector protein that amplifies synthesis
50
What is sexual differentiation and sex determination?
differentiation: process where an individual develops characteristic associated with sex
- 1st step at fertilization
determination: point at which an individual develops as either female or male
- many levels
51
What are the different types of sex?
chromosomal: xx vs xy
gametic: ovaries vs testes (determined by chromo)
hormonal: ratio of [hormone] (determined by gonads)
morphological: differences is physical appearance
behavioral: mating behaviors, etc.
52
What are the ultimate causes of sex difference?
sexual reproduction
- promotes genetic variability
- more resistant to environmental changes
amount of dimorphism determines mating behavior
- high dimorphism: polygamous, M larger, more aggressive, M compete, sexual selection, hippo larger than females
53
What are the proximate causes of sex differences?
sexually dimorphic behaviors
- different in courting, mating, parental load
- hormones can play a role in the development and control of these behaviors
54
What effects do gonadal steroid hormones have on guiding behavioral sex differences?
organizational - programming effects on the brain
- think puberty
activational - temporary, during adulthood
- activate areas that have already been developed
55
What is the geminal ridge?
fork in the development of embryos
- SRY gene: sex-determining region of the Y chromosome
- if present, testes determination factor protein is expressed and activates formation of testes
- if absent, ovary development, may need Wnt4
- releases hormones for further development
56
What are the accessory sex organs?
internal sex organs that connect the gonads to the external environment
- mullerian: female
- wolffian: male
both present during embryonic development
- MIH required for wolffian development
57
What determines the development of external genitalia?
genital tubercle
- when there is an absence of hormones, it becomes female
- if androgens present, male
58
What enzyme is important for converting T into DHT?
5 alpha reductase
- DHT drives development of male external genitalia
- if there is high [T] in females, it can be converted into DHT and male genitalia development
- if enzyme absent in males, they develop female genitalia
59
What happens when someone has congenital adrenal hyperplasia?
a girl has high [progesterone], which is a precursor for cortisol and androgens
- 21 hydrolase (enzyme) for converting to cortisol
- if missing or too much [progesterone], partial masculinization of genitalia
60
What happens when someone has complete androgen insensitivity syndrome (CAIS)?
chromosomally xy, but does not have functional androgen receptors
- important for development of male external genitalia
- MIH produced by testes, so no mullerian. no wolffian bc of AR genes
61
What are the effects of hormones on sexually dimorphic behaviors?
sexual dimorphic mating postures
- under control of gonadal steroid hormones
if you castrate males, no mounting
- T replacement: resume mounting
62
What happens when you give female guinea pigs T while developing?
high dose: partial male genitalia
low dose: no partial male genitalia
both showed that they mount instead of lordosis
63
How can utero relationship affect sexual differentiation?
position of rat pup in uterus
- differences in androgen exposure: if female around 2 male pups, less attractive, more aggressive
maternal stress
- if mother is chronically stressed, M offspring exhibit less rough and tumble play
- almost to point of F
- can affect [androgen] in adulthood
64
What are some endocrine disruptors and how can they affect us?
PBC - found in explosives
- mimics estrogens
Can affect reproductive f(x)
- DDT - caused bird populations to go down, banned, population normalized
- Altrazine - herbicide: affects reproductive development
65
What is parental investment theory?
The extent to which parents compromise their ability to produce more offspring in order to care for the young they have
66
When choosing a mate, who is going to be choosiest?
Whoever has a larger investment of caring for the offspring
| - the sex that contributes the least has to work the hardest to impress the other sex
67
What are the two parental behaviors?
Altricial - offspring born early in development
- often helpless, need more care to survive
- large number of immature young
Precocial - born later in development
- needs less parental care to survive
- smaller # of more developed offspring
68
How do hormones affect parental behavior?
initiates, maintains, develops, and terminates parental behavior
69
What is alloparenting?
caregiving from an individual that is not a genetic parent
| - typically occurs when resources are low and when the alloparent is a sibling
70
What is the hormone that activates parental behavior in animals?
prolactin
71
What is prolactin's relationship with parental behavior? Cortisol?
parental behavior: positively correlated
cortisol: negatively correlated
- inhibits prolactin, can cause parents to abandon babies
72
Why is marsupial development different that eutherian animals?
they typically live in an unreliable environment, and can end their pregnancy if harsh conditions occur
73
What is unique about eutherian development?
```
located in the placenta
more stable, longer gestation, more developed at birth
3 types of care:
- altricial - cares/shelter
- precicial - independent
- neither/semi-precocial
```
74
What did the rate concaveation show?
typically mice take 6 days to like foster pups
| - when a new mother sees foster, they act maternally immediately
75
What did the blood transfusion of a pregnant rat show?
when blood transfused into a rat that has need given birth before, she shows maternal behavior within 24 hours
76
What can trigger maternal aggression?
regulated by progesterone
- P treatments elevates aggression
- pregnancy termination reduces P and eliminates behavior
77
How do hormones play a role in paternal behavior in humans?
neither necessary nor sufficient for basic parental behavior
also triggered by oxytocin
78
How are fathers' hormone concentrations affected by childbirth?
prolactin, estradiol, oxytocin are elevated
| testosterone and cortisol are lowered
79
How does estrogen affect the brain?
promotes maternal behavior by enhancing MPOA (hypothalamus), BNST, septum
lesions to MPOA eliminates maternal behavior
- increased neural activity in MPOA in experiences rat mom exposed to pups
80
How does maternal care affect the offspring in rats?
```
high licking and grooming
- increased glucocorticoid receptors in the hippocampus
- more efficient HPA
low licking and grooming
- opposite
both adopt parental behavior
```
81
How are licking and grooming behaviors passed to offspring?
epigenetic mechanism
- methylation causes a decreased expression of estrogen receptors
- decreased maternal care
cross fostering studies
- if you take a litter from low L&G and switch with high, offspring adopts behavior of foster mom
82
How does pregnancy change the brain?
structural remodeling, similar to puberty
- pruning of areas associated with theory of mind
- becomes more efficient
