New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Exam 3 Study Guide

by: Brittany Woody

Exam 3 Study Guide PSB4504

Marketplace > University of Florida > PSB4504 > Exam 3 Study Guide
Brittany Woody

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Contains lecture and PowerPoint notes for PowerPoints 10-13
Developmental Psychobiology
Dr. Donald J. Stehouwer
Study Guide
50 ?




Popular in Developmental Psychobiology

Popular in Department

This 12 page Study Guide was uploaded by Brittany Woody on Monday April 11, 2016. The Study Guide belongs to PSB4504 at University of Florida taught by Dr. Donald J. Stehouwer in Spring 2016. Since its upload, it has received 26 views.


Reviews for Exam 3 Study Guide


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 04/11/16
Tuesday, April 12, 2016 Exam 3 Ontogeny and Phylogeny - Development of animals vs. development of species - In biology, epigenesis has at least two distinct meanings: • the unfolding development of an organism, and in particular, the development of a plant or animal from an egg or spore through a sequence of steps in which cells differentiate and organs form • the theory that plants and animals develop in this way, in contrast to theories of preformation (small fetus only gets larger) - Epigenesis implies that, at every time point, development is a consequence of the confluence of genes and prior experience, which in turn alters the subsequent expression of genes and their interactions with the environment - Natural selection acts on phenotypes, not genotypes, and those phenotypes are a product of epigenesis. Thus, natural selection is, itself, a product of epigenesis - Canalization: choices lead to adult phenotype - Natural selection requires organism to be adapted during all stages of its life so that it can survive to reproducing age - Locke: Tabula rasa; blank slate upon which experience writes; it has been shown that males and females are different at birth, and not only as a result of their experiences - Rousseau: Preformationist; adult determined in egg, simply unfolds; preformationism was the answer to the difficult question of how a complex adult can arise from the simple gametes; the preformed embryo was complete and a direct result of evolution - Ontogeny recapitulates phylogeny: evolutionary past is reviled during development - Ernst Haeckel was principal advocate of the principle that evolution occurred through changes introduced into the adult at terminal stages - Ontogenies were simply the reflection of prior evolutionary change, which became compressed in time with evolution; thus, evolution was thought to be the mechanical cause of ontogeny; this served to curtail research into developmental biology 1 Tuesday, April 12, 2016 - Laws of von Baer: • During development, general characters appear before special characters; e.g., those of phylum before those of class (e.g. notochord before limbs) • From the more general characters develop the less general and finally the special characters (e.g., differentiation of wings and forelimbs from primitive limb buds) • Animals of different species become increasingly different as they develop. • Young stages do not resemble the adult stages of ancestors, but resemble the young of those ancestors - Eight ways altered ontogeny can produce phylogenetic changes: • Caenogenesis: addition of characters in youthful stages that do not persist into adulthood; amnion of vertebrates, attachment to mother by umbilical cord • Adult Variation: new characters expressed in adulthood; species-specific plumage in birds after final molt, don’t loose “baby feathers” until they are adults • Deviation: developmental alterations persist in adults; gill slits become gills in fish and eustachian tubes in mammals; our middle ear bones (ossicles) are earlier animal’s jaw bones • Reduction: developmental loss of a character; tails of tadpoles and human fetuses • Retardation: delay in the development of a character; wisdom teeth of humans • Neoteny: retention of immature characteristics; vertical face of humans, cephalic flexure in humans, plumage of flightless birds (ostrich, retain juvenile flightless feathers) • Acceleration: characters develop at earlier stages; development of heart in avian embryos, calluses on the knees of ostriches • Hypermorphosis: prolongation of developmental period; ontogeny gets longer as special characters are added during evolution - Heterochrony: change in relative time of development of a characteristic (acceleration and retardation) - Punctuated equilibrium: long periods of evolutionary stasis; little change; marked by environmental stasis; rapid evolutionary change is marked by great environmental change (asteroid causing mass extinction of dinosaurs) 2 Tuesday, April 12, 2016 - Homology: a character in two species is homologous if that same character is present in a common ancestor - Analogy: a character in two species is analogous if it serves a similar function but was not present in a common ancestor; can arise from parallel or convergent evolution • birds and bats do not have a common ancestor that had wings but they each developed wings (parallel evolution) - Forelimbs of human, dog, seal, and bat are homologous; bird and bat wings are not homologous as wings, they are homologous as forelimbs (common ancestor had forelimbs but not wings) - Evolutionary changes in ontogenetic timing are capable of producing morphological evolution; by changing the timing of tissue induction, the number and quality of cells induced may be modified - Problem with determining homology of brains and parts of brains: no fossil record; minuteness of detail in similarities is important; continuance through species of intermediate classes • Similarity of nuclear groups: cell types • Physical resemblance: gross shape and position • Biochemical similarity: neurotransmitter use Similarity of connections: afferent and efferent • • Functional similarity • Similar ontogenetic development - Distinguish between primitive and derived characteristics: • primitive: of two characters, the one that has evolutionary precedence is the primitive character derived: of two characters, the one appearing later is the derived character • - Terminal addition: every evolutionary advance is added as a new stage by reducing the duration of older stages; adding a step at the end of previous ones; neoteny, heterochrony 3 Tuesday, April 12, 2016 - Paedomorphosis: the retention by adults of traits previously seen only in young; occurs by neoteny (the physiological (or somatic) development of an organism is slowed or delayed) or progenesis (sexual development occurs faster) - Evolution is a consequence of natural selection; selection acts on the phenotype, not the genotype, although transmission is primarily genetic; natural selection selects against characters, not for them - Natural selection acts principally on behavior, not directly on the brain - Two general mechanisms by which brains evolve: • invasion hypothesis: addition of new projections and targets • parcellation hypothesis: progressive differentiation of previously undifferentiated tissue - Constraints on evolution: traits must: • be adaptive (or neutral, carried along with adaptation) • be compatible with ontogeny • make use of existing materials and structures - Mammary glands are derived from an embryonic precursor tissue, the mammary ridge - Species that vie birth to litters have many mammaries, whereas humans only have two; however, the number of nipples is an epigenetic feature of development - Decussation: connections in the nervous system crossing the midline - Crossed connections result in escape from an aversive stimulus Neuroendocrinology - Exocrine glands: secrete via ducts and may be secreted externally (mammary glands and sweat glands); not controlled by pituitary gland or hypothalamus - Endocrine glands: secrete directly into the blood and thus are always internal - Atavism: the tendency to revert to ancestral type; an evolutionary throwback, such as traits reappearing which had disappeared generations before 4 Tuesday, April 12, 2016 - Hormones: released from endocrine cells; long latency, long duration of effect (minutes to days); delivered via blood; diffuse actions - Neurotransmitters: released from neurons; short latency, short duration of effect (milliseconds); released directly onto target cells; specific actions - This distinction has become blurred; peptide neurotransmitters/neuromodulators, axon varicosities, release of 5-HT into ventricles, etc. - Pituitary gland (hypophysis) contains anterior pituitary (adenohypophysis) and posterior pituitary (neurohypophysis) - Neuroendocrine cell bodies in the hypothalamus produce releasing and inhibiting hormones which are released from axon terminals that synapse on the primary plexus of the portal system. The hormones travel via the portal veins to the anterior pituitary. Hormone-producing cells in the anterior pituitary respond to the hypothalamic hormones by releasing or inhibiting the release of their own hormones, known as tropic hormones. Tropic hormones travel through the bloodstream and regulate endocrine glands throughout the body - Control of adenohypophysial hormones: all loops are negative feedback loops; increases in the amount of a substance inhibits further secretion of that substance - Indirect acting: neural inputs > hypothalamus > releasing factor > adenohypophysis > trophic hormone > endocrine gland > endocrine hormone > target tissues ACTH, TSH, LH, FSH • - Direct acting: hypothalamus > adenohypophysis > direct acting hormone > target tissues • GH, MSH, Prolactin - Adenohypophysial hormones: • Direct action: somatotropin (growth hormone, GH); prolactin; melanocyte- stimulating hormone (MSH) • Indirect actions: corticotrophin (ACTH); thyrotrophin (TSH); gonadotropins (luteinizing hormone (LH) and follicle-stimulating hormone (FH)) - Thyroxine is synthesized from tyrosine, whereas sex hormones and adrenocortical hormones are synthesized from cholesterol - Sites of hormone actions: 5 Tuesday, April 12, 2016 • nucleus: regulate transcription; epigenetic • ribosomes: regulate translation; protein synthesis • enzymes: turned on via second messengers much like neurotransmitter effects • membranes: alteration of membrane properties much like neurotransmitter effects; phosphorylation of receptor proteins - During development, hormones exert potent trophic effects on both neural and non- neural structures Thyroid Hormones - Growth refers to increase in the size of a tissue, organ, or organism - Maturation refers to emergence of a characteristic through growth or differentiation - Growth hormone excess causes giantism; deficiency results in dwarfism; maturation is not affected in either case; puberty and other milestones are met correctly - Larval stages of bull frogs (tadpole, stage 5- 17) growth is independent of thyroid hormones; get bigger but do not change much, some growth of hind limbs - At stage 17, there is a surge in thyroid hormones and limbs grow; limbs grow inside tadpole then are released in later stages; apoptosis of tail tissues - Thyroxine dependent changes in bull frog: mitosis, protein synthesis in limbs, CNS neurogenesis and apoptosis, teeth grow, eyes move laterally, intestines shorten (adult frogs are carnivores, tadpoles eat vegetation) • frogs do not eat during transition from tadpole to frog because mouth and intestines are changing; they absorb their tail and use the protein as energy; thyroxine triggers apoptosis of tail; frog tail in a beaker with thyroxine will disappear due to apoptosis - Thyroidectomy of frog would result in a tadpole getting larger but never metamorphosing into a frog - Gills degenerate and lungs form; putting thyroxine in tadpole’s environment would result in death because the gills would degenerate before lungs were formed; normally lungs differentiate before gills degenerate, reliant on concentration of thyroxine - If food is scarce, tadpoles will develop faster so that they can leave the water 6 Tuesday, April 12, 2016 - Iodine is sequestered in the thyroid gland by a Na-I pump, whose activity in controlled by TSH - T4 is converted to T3 through de-iodination (removal of iodine) by tissue - Causes of hypothyroidism: • dietary deficiency (iodine): iodized salt in USA • pituitary defect • enzyme deficiency: do not produce thyroid peroxidase, which is necessary to produce thyroxine • thyroid autoimmunity • exposure to I 131: released by nuclear power pants; potassium iodide will counteract effects - Thyroid hormone actions: • direct effects on gene expression and protein synthesis indirect effects via receptor-activated second messenger systems • • products affected during sensitive period for thyroid hormones include neurotrophins and their receptors (BDNF) • NGF, NT family, BDNF, Trk receptors, P75 receptor are all modulated by TH during the sensitive period - Cerebellum of hypothyroid rats: • retarded, prolonged proliferation of granule cells • normal number finally attained but is 25% below normal # on day 14 • shorter parallel fibers; thus, contacts with fewer Purkinje cells; greater cell death during proliferation; secondary migration retarded • proliferation and growth of stellate and basket cells is also retarded • retarded maturation of Purkinje cells: reduced number; reduced dendritic growth; fewer targets for parallel fibers; could be factor in greater death of granule cells along with shorter parallel fibers (“ripple effects”) 7 Tuesday, April 12, 2016 - In rats, proliferation after birth accounts for • 50% of forebrain cells (mostly glia) • 80% of olfactory bulb • 97% of cerebellum - granule cells : birth-15 days postnatal; secondary migration day 15-30 - microneurons: 4-15 days postnatal - basket cells: 4-7 days postnatal - stellate cells: 8-15 days postnatal - Sensitive period for thyroid hormones: birth to day 10 to 12 in the rat; first trimester through 6 month postnatally in humans - Humans: • T4 release begins 10-12 weeks gestation • Increases from 20 weeks to term; a period of development normally associated with: - proliferation - apoptosis - rapid myelination - growth of neuronal processes - synaptogenesis - proliferation in cerebellum (prolonged by hypothyroidism) - Neocortex of Hypothyroid Rats • pyramidal cells: small, densely packed (fewer glia, less neuropil), concentric ring analysis reveals shorter dendrites with fewer high-order branches, fewer dendritic spines • number of potential synaptic contacts reduced by 85%; less spatial summation and neural integration; reliability of processing reduced; range of effective stimuli reduced 8 Tuesday, April 12, 2016 • axons: myelination greatly reduced; slower conduction velocity; with low metabolic rate, accounts for behavioral; sluggishness • these are same features that distinguish the mature from the immature brain; thus, it is as though development is arrested, much like that of the a-thyroid tadpole - Gross characteristics of a “cretinoid” rat: face foreshortened (brachycephaly), lethargic, hair is thin, learning and memory impaired, brain weight reduced, growth retarded after 12 to 15 days of age (after several months in humans; apparent by 18 months, but by then CNS damage has occurred), O consump2ion (metabolism) lowered, cold intolerance, deafness • delayed somatic maturation as indicated by delayed eye, ear, vaginal opening; delayed endochondral ossification - Behavior of “cretinoid” rat: fits of activity when stimulated; susceptible to seizures; startle response, righting reflex, placing responses retarded; persistence of mass- action wriggling to noxious stimulus; deficits in both learning and memory  - Human development of cretin: “The mental capacity varies within narrow limits; an intelligent adult cretin may reach the intellectual development of a child 3-4 years of age, though more often the standard attained is even below this. The child cretin learns neither to walk nor talk at the usual time. Often it is unable even to sit without support. Some years later a certain power of movement is acquired, but the gait is waddling and clumsy. Speech is long delayed, or in bad cases may be almost entirely lacking. The voice is usually harsh and unpleasant. Of the senses, smell and taste are but slightly developed, more or less deafness is generally present, and only the sight is fairly normal. In the adult the genital organs remain undeveloped. If the cretin is untreated he rarely has a long life, thirty years being an exceptional age. Death results from some intercurrent disease.” - Effects of thyroid hormones: organizational effects: structural, sensitive period, irreversible in adulthood • • activational effects: metabolic, no sensitive period, reversible throughout life Sex Hormones - Definitions of sex (gender) can be genetic, gonadal, hormonal, morphological, behavioral (gender role behavior), identity 9 Tuesday, April 12, 2016 - Sexual dimorphism: phenotypic differences between males and females; can be anatomical, physiological, behavioral, cognitive; qualitative or quantitative - Effects of sex hormones: • organizational: structural, sensitive period, irreversible, masculinization/ defeminization • activational Effects: act on existing structure, no sensitive period, reversible - Bipotential tissues: undifferentiated tissue that can differentiate into either a male or female form - Castrate male hamster at birth: before period of brain differentiation, test in adulthood • inject with testosterone, place with receptive female: male-typical behavior low mounting, intromission (ejaculation not possible) • inject with estrogen and progesterone, place with male: female-typical behavior high; darting, ear-wiggling, lordosis (arching of back) - Neuter female hamster at birth and inject with testosterone: before period of brain differentiation, test in adulthood inject with testosterone, place with receptive female: male typical behavior high • (mounting) • inject with estrogen and progesterone, place with male: female-typical behavior low (ear-wiggling, darting, lordosis) - Differentiation of the brain: two processes, both dependent on fetal androgens • masculinization: induction of male characteristics • defeminization: suppression of female characteristics - Estradiol is the sex hormone primarily responsible for the masculinization of the brain. - alpha-fetoprotein binds to estradiol extracellularly and prevents entry into the cell in females - In rats, a female embryo that develops between two male embryos is exposed to more testosterone than is a female embryo that develops between two female embryos 10 Tuesday, April 12, 2016 - High concentrations of estradiol receptors are found in the pituitary and hypothalamus, including the pre-optic area of the anterior hypothalamus; these areas are involved in sexual and reproductive behaviors - HPA axis (AKA LHPA axis): the limbic–hypothalamic–pituitary–adrenal axis is a complex set of direct influences and feedback interactions among three endocrine glands: the hypothalamus, the pituitary gland, and the adrenal glands; controls reactions to stress and regulates many body processes, including digestion, the immune system, mood and emotions, sexuality, and energy storage and expenditure - Congenital adrenal hyperplasia (CAH): are any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of mineralocorticoids, glucocorticoids, or sex steroids from cholesterol by the adrenal glands - Newborn girls with CAH: genitalia masculinized; gender role masculinized; cognition higher than female norm; orientation is heterosexual with an increased prevalence of lesbianism - SAT given to 7th and 8th graders; boys= girls on verbal section; boys do better than girls on math; highest score every year is a male • measure of ability not achievement: students were tested on concepts not yet covered in school differences cannot be attributed to differential courses, social conditioning, or math • anxiety • fewer girls accepted an offer of accelerated training and more girls dropped out; afraid to different, did not like boys in the program • studies only used top 3% of students - Left half of brain controls: right hand, logical thinking, language ability, writing, science and math work - Right half controls: left hand, musical and artistic ability, perception of space, imagination and fantasizing, body control and awareness - Geschwind’s theory of cerebral lateralization: differences in maturation rates between the cerebral hemispheres are mediated by circulating testosterone levels, and sexual maturation acts to fix the hemispheres at different relative stages of development after puberty; male brains mature later than females, and the left hemisphere matures later than the right 11 Tuesday, April 12, 2016 - During flow phase of menstrual cycle: perform well on verbal skills and motor tasks but poorly on spatial tasks - During ovulation: perform well on spatial tasks but poorly on motor and verbal tasks - Size of central subdivision of the bed nucleus of the stria terminals (BNST) is related to sexual identity but not to sexual orientation 12


Buy Material

Are you sure you want to buy this material for

50 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Allison Fischer University of Alabama

"I signed up to be an Elite Notetaker with 2 of my sorority sisters this semester. We just posted our notes weekly and were each making over $600 per month. I LOVE StudySoup!"

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.