Exam 3 Psychobiology

Turner’s syndrome

missing a chromosome on the 23rd pair, marked as XO

• characteristic features of webbed neck, abnormal elbows, etc.

Konrad Lorenz

a German etholist who won a Nobel prize, focused on the final form/goal, where things go to

Daniel Lehrman

an American researcher and founder of Animal Behavior at Rutgers, wrote a chapter critiquing Lorenz’s theory

what was the debate between Lorenz and Lehrman over?

a difference in emphasis

• Lorenz: where things go to

• Lehrman: where things came from

“binaryness”

if you view everything through a binary lens, but things like development aren’t always binary

• development is crucial to understanding sex

brain differences between sexes

• parts of frontal cortex and limbic systems larger in women

• parts of parietal cortex and amygdala larger in men

• greater neuronal density in temporal lobe (language processing and comprehension) in women

macroanatomy between male and female

• larger brain volume and weight in males

• some cortical areas larger for both

• women have more grey matter than men when corrected for brain size

• larger grey:white ratio in women

what is an issue with emphasizing sex brain differences?

they are “overhyped” and have no huge differences

• men’s brains are bigger in relation to what? more cells, strength, myelin, or something else?

what do dendritic spine graphs tell us about stress?

females respond more dramatically to stress

• stress leads to learning in males but a reduction in females

Celia Moore’s framework

studied effects of male hormones on male brains and maternal behavior

• mother rats lick male pups 6x more than female pups

why do mother rats lick their male pups more than females?

the male pups became masculinized through testosterone, which affects their urine and the mother’s behavior

• mother prefers the testosterone

examples of categorization

• naming brain structures

• assigning functions to structures

• naming and categorizing genes

• categorizing sex binary (male and female)

Alice Dreger

wrote about “The Age of Gonads” and the medical invention of sex

• histology in 19th century had a quest to find out “true” sex

The Age of Gonads

a time of classifying gonads in order to maximize binary categorizations of sex

• ended by Blair-Bell

what was the result of ending “the age of gonads”?

each body was allowed only one “true” sex, which was determined and even created by the medical doctor

Crouch claims that the birth of an infant with ambiguous genitalia is a…

medical and psychosocial emergency

Crouch ideas

• earlier doctors concerned with discovery of sex, while modern idea is the creation of sex

• intersexed children are invested with negative meaning through naming

John Money and Anke Ehrhardt

describe newborns as “psychosexually neutral”

• different types of men and women

Dr. Harry Benjamin

a German medical endocrinologist who performed sex change surgery in the U.S.

• supported Christine Jorgensen’s transition

• consulted with Kinsey about a transgender kid

Christine Jorgensen

a high profile trans woman from the 1950s

• denied a marriage license

• entertainer, author, lecturer, leader in sex-alignment surgery in US

endocrine

relating to or denoting glands which secrete hormones or other products directly into the blood

exocrine

relating to or denoting glands that secrete their products through ducts opening onto an epithelium rather than directly into the bloodstream.

hypothalamus

a collection of nuclei at the base of the brain

• Cells at the base are specialized neurosecretory cells that function primarily as glands

Terminals release ________ in response to nerve impulses (like transmitters) but the neurohormones are released into ______ of the pituitary, rather than into synaptic space.

neurohormones; portal system

anterior pituitary secretions

TSH, ACTH, LH, FSH, GH, and prolactin (tropic hormones)

posterior pituitary secretions

oxytocin and vasopressin

hypophysis

two glands, fused into one (another name for pituitary gland)

GH (growth hormone) targets…

bones and tissue

prolactin targets…

mammary glands

FSH and LH target…

ovaries, testes

ACTH targets…

adrenal cortex

TSH targets…

thyroid

oxytocin targets…

mammary glands, smooth muscle in uterus

anti-diuretic hormone (ADH) targets…

kidney tubules

magnocellular neurons

oxytocin and vasopressin (posterior pituitary) are manufactured here

oxytocin and vasopressin are…

manufactured in magnocellular bodies and transported down axons

• stored in vesicles at cell terminals in the posterior pituitary

• released in response to neural impulses, classic NT

adrenal medulla

inner adrenal gland that releases EP, NE, and DA into general circulation

• also releases enkephalins

adrenal cortex

outer adrenal gland that three divided hormonal zones that belong to a class of steroid hormones

aldosterone

a steroid hormone that regulates sodium levels in the blood; its secretion is controlled angiotensin II

two functions of the gonads

1. gamete production

2. hormone production

gonad function is regulated by…

tropic hormones of the anterior pituitary

seminiferous tubules

site of spermatogenesis

• long, convoluted tubules

• can identify sperm at various stages of maturation

leydig cells

produce the steroid hormones, primarily androgens, under the influence of the anterior pituitary

ovaries

produce gametes and hormones

• cyclic in both functions

• fetal ovaries contain ½ million immature follicles

testes vs ovaries function

testes are tonic in gamete production and secretory activities, while ovaries have cyclic changes

5 kinds of sex (male vs female, you filthy pervert)

1. chromosomal: chromosomes, genes, proteins

2. gonadal: testes/ovaries

3. hormonal: testosterone, estrogen, androgen

4. morphological: form of external body

5. behavioral: characterizations of “pure” roles

gender role

what we present in society

gender identity

much more personal, how we perceive ourselves

fertilization

two cells interacting, rather than sperm “drilling” into the egg

• when a sperm reaches an egg, it “spoons” with it, membranes melt and they merge into one

mutual activation by sperm and egg

before sperm activates egg, female reproductive tract and egg activate the sperm.

• once two are together, sperm can activate maturation of egg, enabling it to finish meiotic cell division

capacitation

oviduct cells interact with sperm cell’s membrane

• sperm are immature and cannot fertilize the egg, requires capacitation

chromosomal sex determination

said to occur when an ovum is fertilized by a sperm bearing X or Y chromosome (male delivers sex-determining factor)

germinal ridge

thickened ridge of tissue that forms on ventromedial surface of each protokidney

• can develop into a testis or an ovary

gonadal sex differentation

bipotential

embryonic gonad is “indifferent” and can become one sex or the other

TDF

testes determining factor; if cells in germinal ridge contain Y → genes will express TDF protein

in the presence of TDF…

the medulla of the ridge develops further into a testis

in the absence of TDF…

outer cortex of ridge develops to form an ovary

two types of developmental pattern

1. single, bipotential (embryonic gonad becomes either testis or ovary

2. dual anlagen (presence of TDF or not)

Wolffian duct system

develops into male accessory sex organs, connecting testes to outside

• seminal vesicles and vas deferens develop from this

Mullerian duct system

becomes female accessory sex organs, connecting ovaries to outside

• develops into fallopian tubes, uterus and cervix

genital folds

ridges that flank urogenital sinus during embryonic development

genital tubercle

the meeting of genital folds at the front end of the urogenital opening

androgens

responsible for masculinizing the external genitalia, more “variation”

• each direction is mutually exclusive

in the absence of androgen…

female morphology develops

female clitoris and labia develop from…

genital tubercle and folds (respectively)

male penis and scrotal sac develop from…

tubercle and fusing of genital folds, respectively

5a-reductase and DHT functions

testosterone is converted to DHT by 5a-reductase, present in both male and female

• man with less 5a have incomplete external genitalia

• if women have high levels of androgens, she can convert to male external genitalia

congenital adrenal hyperplasia (CAH)

a group of genetic disorders that affects the adrenal glands, may not produce enough hormones

turner’s syndrome

disorder where you’re missing a second sex chromosome, represented as XO or just X

• characteristic features: short, infertility, webbed neck, long arms, irregular elbows

testicular feminization mutation (TFM)

now called androgen insensitivity, occurs when a male has XY but is resistant to hormones (androgens) producing a male appearance

• some female physical traits, yet genetic makeup of a man

freemartinism

when cows birthed opposite sexed twins, the female twin was sterile and had masculine traits

• masculinized behavior and non-functioning ovaries

Crews’ (1994) ideas

• expresses amazement that we don’t know why sex evolved

• emphasizes a comparative perspective, and that it is less universal that previously assumed

two roles of sex steroids

1. organizational: the initial role

2. activational: exerted later in life

whiptail lizards

parthenogenic whiptail lizards
take turns displaying male sexual behavior, thereby improving ovulation

parthanogenesis

a natural form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization

effects of embryos on each other

prenatal hormone environment has more effect than sex organs

• females with males on both sides are exposed to more testosterone

temperature-dependent sex determination

low vs high temperatures can produce a male vs female

behavioral sex determination

most cases in hermaphroditic species

• sex change can be triggered by alterations in social environment

differences in sexual development (DSD)

a group of rare conditions involving genes, hormones and reproductive organs, including genitals

body identity integrity disorder (BIID)

an extremely rare condition whereby an able-bodied and apparently
normal individual describes a long standing desire to have a limb amputated

Carl Elliott’s “The Perfect Voice” takeaways

• asks how exactly our voice is identity

• Stephen Hawking identified more with American computer voice than a British version, despite being British

• tension between natural and artificial (given vs created)

• Hawking’s example shows flexibility of identity

primum non nocere

“above all, or first, do no harm”

• argument surrounding BIID

• however is too vague, as surgeons have to cut a healthy abdominal wall to remove a damaged appendix

Tiers of ethical rules

1. Particular judgments and actions

2. Rules

3. Principles

4. Ethical theories

moral dilemmas

arise when either of two opposing views can be taken on the basis of moral considerations

• happens during moral deliberations

judgment

expresses a decision, verdict or conclusion about a particular action

rules

state the actions of a certain kind ought (or ought not) to be done because they are right (or wrong)

principles

more general and fundamental than moral rules and serve as the foundation or source of justification

theories

bodies of related principles and rules

utilitarianism

gauge the worth of actions by their ends or consequences (focuses on outcomes)

• value is said to be nonmoral because such activities
  are not fulfilling a moral obligation, but have more
  general goals

deontological theories

some features of acts other than their consequences make them right or wrong

principle of autonomy

a guide on how to treat self-determining rights

principle of nonmaleficence

one ought not to inflict evil or harm (what is bad)

principle of beneficence

one ought to prevent and remove evil, and do or promote good