Lecture 10

Question 1

gender –

Answer 1

the behaviors and attitudes that a given culture considers to be
masculine, feminine, or an alternative

Question 2

sex

Answer 2

a trait that determines whether a sexually reproducing organism produces male or female gametes

Question 2

Gonadal hormones -

Answer 2

(e.g., testosterone and estradiol) mediate early changes in the developing brain to assure that activation of the same
circuits by the same hormones in adulthood will produce the
appropriate reproductive behaviors

Question 3

Evolutionary perspective of gender:

Answer 3

gender variability could optimize adaptation for us as a species by allowing us to maximize our exploitation of available resources, and reproductive/ rearing success at the overall population level

Question 3

Reproductive behavior is a broad term encompassing:

Answer 3

– Behaviors for attracting and finding a mate
– Copulation for exchange of gametes, or reproductive cells (i.e., sperm, ovum)
– Care and nurturing of offspring after they are born

Question 4

Sex hormones are secreted by _______ and they have a _______ structure,

Answer 4

gonads (testes, ovaries), steroid
hence they are called gonadal steroids or
gonadal hormones

Question 4

Androgens –

Answer 4

gonadal steroids synthesized in
testes
– Testosterone is an important androgen

Question 5

23 chromosome pairs in humans; 22
_______ and 1 ___ chromosome

Answer 5

autosomes, sex chromosomes
— X or Y
– XY pair = male
– XX pair = female

Question 6

Testosterone

Answer 6

is an important androgen

Question 7

Estrogens –

Answer 7

gonadal steroids in females synthesized in ovaries
– Estradiol is an important estrogen

Question 8

Estradiol is

Answer 8

an important estrogen

Question 9

Sex determination –

Answer 9

process by which the decision is made for a fetus to
develop as a male or a female

• If the sperm that enters the egg has a Y chromosome, the offspring is male; if an X chromosome, the offspring is female

Question 10

There is a single gene on the Y chromosome called ________

Answer 10

Sry, which stands for
sex-determining region of the Y chromosome
* Sry directs the formation of testes from the “bipotential” gonad (gonadal
precursor to either testes or ovaries)
* Everything else follows from this initial step

Question 10

Sexual differentiation –

Answer 10

process by which individuals develop either
male or female bodies and behaviors

Question 11

After sex determination……

Answer 11

, hormones secreted by gonads, mainly the
testes, direct sexual differentiation
(remember if no testes form, then
one becomes female)

Question 11

The ______ and the _______ ducts
connect the indifferent gonads to the
body wall

Answer 11

wolffian and müllerian

Question 12

In females,________ ducts develop into the female
reproductive organs (oviducts, uterus, vagina)

Answer 12

müllerian

Question 13

In males, ________ ducts develop into the male
reproductive organs
(epididymis, vas deferens, seminal vesicles)

Answer 13

wolffian

Question 13

Steroids have an organizational effect only when present during a _________ in early development

Answer 13

sensitive period
* Depending on the species and the behavior, it may be before birth or just afterwards, in the neonatal period

Question 14

Organization/ Activational hypothesis
(OAH)

Answer 14

William Young

Organizational”
– During gestation, the onset of testosterone secretion in males defines
the sensitive period for sexual differentiation in the brain start of
masculinization
– The end of this first sensitive period is defined as when females are
no longer sensitive to the effects of androgens
* “Activational”
– Later surge of gonadal hormones in puberty and beyond serves to
activate the previously organized brain networks

Question 15

OAH - Rodent sex

Answer 15

The female displays proceptive behaviors,
and adopts an arched-back posture called
lordosis, allowing the male to mount the
female to engage in intromission (i.e., active
process of inserting the penis into the vagina)

Question 16

one steroid signal——masculinizes the body, the brain, and
behavior, all during gestation

Answer 16

testosterone

Question 17

The term ___________ means that
males and females have marked sex
differences in appearance

Answer 17

sexual dimorphism

• Sexual dimorphism also occurs in the brain

Question 18

In rats, a subregion in the_________ is larger in
many males relative to females

Answer 18

preoptic area
(POA) of the hypothalamus

Question 18

Called the ----—lesions in this area disrupt ovulatory and copulatory behaviors in females and males, respectively

Answer 18

sexually dimorphic nucleus of the POA (SDN-POA)

Question 19

_________ and __________ show some differences that affect: – Emotionality – Aspects of learning and memory – Stress responsiveness – Affiliative behaviors

Answer 19

Hippocampus and amygdala

Question 19

There are 4 Key CNS structures altered by organizing effects of gonadal steroids

Answer 19

1. Sexually dimorphic nucleus of the preoptic area (SDN–POA) 2. Anteroventral periventricular nucleus of the preoptic area (AVPV–POA) 3. Principal nucleus of the bed nuclei of the stria terminalis (pBST) 4. Spinal cord, nucleus bulbocavernosus (SNB)

Question 20

The ___________________ is in the POA

Answer 20

third interstitial nucleus of the anterior hypothalamus (INAH-3), * INAH-3 was larger in men than in women, and larger in heterosexual men than in homosexual me

Question 21

Homeostasis -

Answer 21

regulation of biological processes that keep certain body variables within a fixed range

Question 22

set point -

Answer 22

refers to a single value that the body works to maintain – Examples: Levels of water, oxygen, glucose, sodium chloride, protein, fat and acidity in the body

Question 23

Processes that reduce discrepancies from the set point are known as

Answer 23

negative feedback

Question 24

2 pancreatic hormones:

Answer 24

– Insulin – promotes glucose uptake into cells; promotes conversion of glucose to glycogen - a more storage-friendly carbohydrate – Glucagon – increases blood levels of glucose; mediates breakdown of glycogen back to glucose

Question 25

In people with____________, insulin levels remain constantly low, so blood glucose levels stay elevated

Answer 25

diabetes mellitus – People eat more than normal, but excrete the glucose unused and lose weight * Type 1 – juvenile onset diabetes; pancreas stops producing insulin * Type 2 – adult onset; assoc. with obesity; consequence of reduced sensitivity to insulin

Question 26

Bilateral lesions of the _____________could cause obesity in rats (i.e., hyperphagia)

Answer 26

ventromedial hypothalamus (VMH)

Question 27

Bilateral lesions in the_____________ caused rats to lose weight (i.e., aphagia)

Answer 27

lateral hypothalamus (LH)

Question 28

Arcuate nucleus (of the hypothalamus) –

Answer 28

appetite control center that is governed by a variety of circulating hormones in the periphery (e.g., insulin, leptin, ghrelin, cholecystokinin.

Question 29

Leptin –

Answer 29

produced by the body’s fat cells when amount of fat stored reaches a certain level when levels are low it signals to the Arcuate to increase appetite