Behavioral Exam 1
Why did the single testis implanted into the chicken's abdominal cavity grow to be twice as large as a normal testis (i.e. what is the mechanism of compensatory hypertrophy)?
A biological factor that regulates testis growth varies depending on the presence of 1 or 2 testes.
What is the adenohypophysis?
Anterior pituitary lobe (aka pars interior) developmentally originates from roof of mouth
What is "extirpation" and why is it a useful method for studying the effects of hormones on the body?
Extirpation" is the removal of an endocrine gland; it is useful because it allows researchers to experimentally determine the effects that the hormone had on subject behavior.
Why is it important for researchers to determine whether hormone concentrations and the behaviors that may be regulated by that hormone are covariant?
For hormone concentrations and behaviors to be covariant it means that as the hormone levels increase so do the behavioral activity levels. Important for discriminating between the physiological vs pharmacological relevance of a replacement substance.
Why is it often important to include "hormone replacement" treatment groups along with extirpation treatment groups in order to identify the function of a particular hormone?
Hormone replacement therapy is treating an individual who lacks a particular hormone with that hormone or a drug substitute for that hormone; restoration of the hormone should reinstate or normalize the behavior
What are the differences between an intracrine factor, autocrine factor, a paracrine factor, an endocrine factor, an exocrine factor, and an ectocrine factor?
Intracrine substances regulate intracellular events: autocrine substances are feedback to influence the cell: paracrine secretes to affect adjacent cells: endocrine secrete into the blood stream: ectocrine are released into the environment
What is meant by the phrase that a hormone is an "intercellular signal"?
It is a chemical substance, a molecule that is secreted by one cell of the body and modifies the function of another cell of the body.
Can the hypothalamus be divided into subnuclei?
It is divided into subnuclei: e.g. suprachiasmatic nucleus, PVN
What is the group of hormones that we have discussed this unit that are not systemic hormones, and why are they not systemic?
Most releasing hormones are not systemic. This is because they are part of 2nd and 3rd order arrangements. Which means there is only enough to send a signal for
What are some physical and behavioral consequences of castration of an immature male chicken?
No comb or wattle; less tail feathers; no crowing or fighting with other males; no sex drive
Developmentally, where do cells of the adenohypophysis and the neurohypophysis originate from?
Posterior pituitary lobe (aka pars nervosa) developmentally originates from the brain
What is the neurohypophysis?
Posterior pituitary lobe (aka pars nervosa) developmentally originates from the brain
What are the Wolfian duct and the Mullerian duct?
The Müllerian duct gives rise to female reproductive organs. The Wolffian duct, which generates male reproductive organs and the kidney
Why can the hypothalamus be considered the MASTER Master Gland of the endocrine system?
The Pituitary Gland is considered the Master Gland and the hypothalamus is considered the Master of the master gland.
What determines whether or not a particular cell in the body is a target for a systemic hormone?
These target cells should express specific receptors
Can a particular type of molecule be both a hormone and a neurotransmitter?
asopressin and oxytocin, two peptide hormones that are released into the circulation from the posterior pituitary, neurotransmitters at central synapses. both hormones and neurotransmitters.
Where is the hypothalamus located?
below thalamus, base of forebrain, surrounds third ventricle
What is the difference between endocrine glands and exocrine glands?
exocrine glands secrete substances outside/ ductal system to an epithelial surface, endocrine glands secrete products directly into the bloodstream
What are two examples of tissues that contain endocrine cells which are not "clumped" together into an endocrine gland?
gut, liver, lung, heart, adipose tissue, muscle
What are some physical and behavioral consequences of removing the testes (castration) of a person after they have reached puberty? effects reflect organizational or activational effects of gonadal steroids?
in humans often little effect; in some, but not all cases, reduces sex drive"; in non-humans, usually abolishes sexual behavior
What are the different classes of chemical structures of which most hormones are members? What are their characteristics?
peptides (proteins) and steroid hormones
What are some physical and behavioral consequences of removing the testes (castration) of a person before they have reached puberty? Effects?
short stature, long arms, no beard, no lowering of voice. These reflect organizational effects of gonadal steroids.
In A. A. Berthold's experiments, why did re-implantation of a testis into the abdominal cavity of a castrated chicken allow the chicken to develop into a "normal" rooster, even though no neural connection was established with the implanted testis?
something released from the testis into blood stream could affect the entire body
