Hormones 3

define Kisspeptin, is it the only factor or whether GnRH or GnIR, what is the other

a peptide in hypothalamus which stimulates gonadotropin releasing factor in hypothalamus. (triggering HPG axis) so its key in causing puberty onset

factor that infleunced whether GnRH or GnIH. biologcal effect will also tell the hypothalamus whether to produce more or less

Gonads

Ovaries and the Testes

two functions:

Produce hormones

testosterone, estrogen, progestin

Produce Gametes:

sperm (testes), eggs (ovaries)

Ovaries produce which hormones

after signaled by GnTR factor, it will produce

Lutenizing hormone → estrogen, progestin

FSH → helps to develop folicle, and make estrogen

Testes produce which hormones

LH → testerone

FSH → promotes spem mato genesis

Egg/Ovum Gametes

eggs produced by ovaries

How do Ovaries produce hormones what is hormones function

hormones (estrogen, progestin) produced in cycles depends on species

estrogen:

shapes female tissues, breast dev, matures reproductive organs

(have organizational effects)

progesterone: regulates reproductive cycles, prepare uterus for pregnancy

Sertoli cells

cells in testes which produce sperm. is regulated by FSH

Testes: how do they produce gametes, and hormone. what is the function of hormone produced

FSH from pit. regulates sperm produciton →

Sertoli cells - make sperm

LH from pit stimulates →

Leydig cells - make testerone (androgen)

testerone has organizational effect before birth

male reproductive organs, brain dev

later in puberty matures body: body hair, deep voice, genital grows

what is meant by steroid conversion, describe proportion of sex hormones in sexes and why this is

hormones can be changed into another hormone so we contain both

progestins can become androgens and androgens can be come estrogens

males and females just differ in proportion of their sex hormones depending on what gonad they have. still both:

ovaries → aromatase will convert most testerone, androgens into estrogen

testes → if less aromatase small amt of estrogen will be made

Posterior Pituitary (structure, hormones, process with axon)

made of Magnocellular neurosecretory cells: large and resides in

SON nuclei and PVN nuclei hypothalamus

stores hormones: oxytocin and vasopressin from hypothalamus, and eventually release them into bloodstream

Magnocellular cells have long axons that go from hypothalamus to posterior pituitary (along pituitary stalk)and release its hormones into the blood

axons also go into the brain and letting these hormones in so they act as NT/ neuromodulators

Oxytocin as hormone and neuropeptide

function as hormone: reproductive and parenting behavior

promotes lactation, uterine contractions

neuropeptide / NT:

modulates: social bonding, trust, maternal behavior,

stress, anxiety, social recognition

from hypothalamus

Milk letdown reflex (describe process)

1. baby stimulates nipple

2. activate hypothalamus neurons to release oxytocin

3. triggers mammary cells to contract releasing milk

crying can also trigger this process

Vassopressin

also called antidiuretic hormone

works with kidney to regulate amt of blood and salt

increases blood pressure (so little blood left can move)

when water levels down this hormone signals kidneys to conserve water, make less urine. 

modulates:

pair bonding, aggresion

stress, anxiety, depression

is a hormones role in behaviour always going to be the same

(ex. testosterone always = aggression)

no the behaviour from a hormone highly depends on the context the same hormone that can promote agression can promote social bonding

Does Testosterone cause aggression

no. testerone has different behaviour depending on the context

no hormone will create a behaviour thats not already there.

hormones amplify preexisting social tendencies, patterns

ex.

reduce refractory period of neurons: neurons fires more (amplify behaviour)

testerone can be release due to psychological factors

seeing your team winning → increase

people who thought they had more testerone behaved how they thought it would work: more selfish, confident

Experience modulates effects of testerone

if you have more prioir agressive experiences you act agressive testerone or not

basal testoerine levels ppor predictor of agression individual comparisons

what is the challenge hypothesis

high testerone levels will only increase aggressive behavior when there is a social challenge

testerone doesn’t increase when theres a challenge but when they need to maintain status (can be fighting or being nice)

what are pro social effects of oxytocin

recognition of people in your species (conspecifics)

ingroup preference, social cohesion

pair bonding (pref for your mate)

emotional recognition

increase trust, empathy, cooperation

responsive to social reinforcement (smile, frowns)

why is oxytocin not universally prosocial

increased maternal aggression

aggression and biases to outgroups

how is Vassopressin related to pairbonding

Prairie voles which are monogamous and pair for life, when studying the brain they fond theres lots of vesopressin receptrs expressed (different from meadow voles)

How do neural systems interact to produce responses

(neuro-endorine coordination)

environmental stimuli trigger sensory input in brain

actions modify sensory input

trigger hormone release

Neural-Neural

neuron communicates with neuron using NT

(ex. sensory input activates motor circuit)

Neural-Endocrine

Neurons trigger endocrine cells to release hormones

(hypothalamus nuclei → anterior pit.)

Endocrine-Endocrine

hormones from one endocrine gland affects another endocrine gland

ACTH from pit gland stimulates cortisol release from Adrenal gland

Endocrine to neural

when hormones acts on the brain and change brain activity

Oxytocin influencing social behaviour