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B&B
Final
135
Biology
Undergraduate 1
12/09/2007

Additional Biology Flashcards

 


 

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Term

Chromosomal sex

Definition
- determines which gonads form in embryonic individual—females have ovaries; males have testes
Term

Gonadal sex

Definition
- determines the hormonal environment in which the fetus develops, and steers morphological development in a male or female direction
Term
Gametic sex
Definition
- female’s ovary produces ova (eggs), while the male’s testis produces sperm
Term

Hormonal sex

Definition
- female vertebrate species tend to have high estrogen-to-androgen ratios of circulating steroid hormone concentrations; males have the opposite pattern
Term

Morphological sex

Definition
- differences in body type between males and females
Term

Behavioral sex

Definition
- behavioral differences between males and females
Term

        Organizational effects

Definition
: differential exposure to hormones act early in development to organize the neural circuitry underlying sexually dimorphic behaviors
Term

        Activational effects

Definition
: differential exposure to sex steroid hormones later in life activate the neural circuits previously organized
Term
Describe the stages of sex determination.
Definition

         Hormonal secretions from the developing gonads determine whether the individual develops in the male or female direction

         The mammalian embryonic testes produce androgens, as well as peptide hormones, that steer the development of the body, central nervous system, and subsequent behavior in the male direction

         The mammalian embryonic ovaries do not secrete high concentrations of hormones

         In the presence of ovaries, morphological, neural, and subsequent behavior develops in the female direction

         The prevailing hypothesis about the initiation of sexual differentiation indicates that the gonads are differentiated by genetic influences (sry gene), and that all other sexual differentiation reflects hormonal mediation. However, it has been suggested that some sex differences in brain and behavior might be mediated directly by genes

Term

a.      First, describe the genetics involved (hint: there is a gene on a particular chromosome that determines whether development proceeds in the male direction)

 

Definition
sry
Term

a.      Second, the presence of this gene causes a structure to develop in the male direction. What is this structure? And what does it do? (hint: it secretes something that affects the developing nervous system and body)

 

Definition
Testes, testosterone
Term

a.      In the absence of the gene, the structure develops in the female direction. What is this structure and what does it do?

 

Definition
Ovaries, they make eggs.
Term

  Describe how the accessory sex organs develop in either the male or female direction. (hint: mention the Wolffian and Mullerian ducts, in addition to a protein hormone called MIH).

Definition
  • Accessory sex organs connect the gonads to the outside environment

The müllerian duct system develops into the female accessory organs; This occurs by default. MIH prevents the Müllerian duct from developing into female internal genitalia (this occurs in males)

The Wolffian duct system develops into the male accessory sex organs; this requires testosterone (T). In the absence of T, the Wolffian duct regresses (this occurs in females)

Because these two primordial systems are present early during ontogeny, it is possible for both systems to develop in a single individual

Term
Which area of the brain is extremely important for the expression of male sexual behavior?     
Definition
sexual dimorphic nucleus
Term

Where is the SDN located in the brain? 

Definition
Anterior Hypothalamus
Term

4.      How do steroid hormones affect behavior?

Definition

They do not cause behaviors to occur. Steroid hormones activate certain genes in neurons. Activation of genes can lead to: increase or decrease in the number of neurotransmitter receptors, changing the presence or amounts of enzymes that affect neurotransmitter production (these changes directly affect behavior)

Example: Estradiol facilitates male sexual behavior by promoting activity (e.g., dopamine neurotransmission) in various components of the neural circuits that regulates male sexual behavior

Term

Sexual behavior in female rodents is highly dependent on sex hormones. In fact, sexual behavior is restricted to a particular phase of the ovarian cycle. Females that are sexually active are said to be in behavior estrous. Describe behavioral estrous.

Definition

Seek out males

Initiate/permit copulation

Remain in close proximity to male

Term
Why isn’t the reproductive cycle of female humans and some primates considered an estrous cycle? 
Definition
Mating behavior is not confined to a particular phase of the ovarian cycle.
Term
What is the HPG axis? 
Definition
a way of referring to the combined effects of the hypothalamus, pituitary gland, and gonads as if these individual endocrine glands were a single entity.
Term
This (HPG) axis is made up of various structures; how do they communication with each other (is it paracrine or endocrine communication)? 
Definition
Endocrine
Term

Is the HPG axis active in males or females or both?

Definition
Both.
Term

4.   Which hormones are released by the anterior pituitary? Posterior pituitary? 

Definition

Follicle stimulating hormone.

 

Oxytocin and estradial prolactin.

Term

4.   Describe the hormonal correlates of the female cycle. (Note: describe how the brain controls the release of hormones from the ovaries; also discuss the process of negative and positive feedback)


Definition

Hypothalamus secretes pulses of releasing hormones

These hormones stimulate the release of gonadotropins from the anterior pituitary

Pulses of gonadotropins drive the release of sex steroid hormones by the gonads

As sex steroid hormone concentrations increase, secretion of gonadotropins is reduced (negative feedback), which results in decreases in gonadotropin-stimulated steroid hormone synthesis

Castration effect: removal of the ovaries (ovariectomy) results in sustained elevated gonadotropin concentrations, as well as elevated releasing hormone secretion (removal of negative feedback)

Term
High levels of Estrogen cause the release (surge) of a hormone from the anterior pituitary. What is the name of this hormone?

Definition
GnRH surge 
Term

Why is this surge (GnHP) important for female reproduction?

Definition
Stimulates ovulation.
Term

Which area of the brain is critical for female sexual behavior?

Definition
Hypothalamus and Pituitary gland.
Term

4.      Which area of the brain is critical for female sexual behavior?

Definition
Hypothalamus and Pituitary gland.
Term

Reproductive effort can be divided into mating effort and parental effort. Describe common mammalian sex differences in reproductive effort. (hint: organisms put more effort into the type of effort that maximizes their reproductive success)

      
Definition
    Men spend more time reproducing and Women spend more time raising children
Term

Which area of the brain is important for the expression of parental behavior?

 

Definition
MPOA, amygdala, nucleus accumbens, limbic system
Term

 Estrogen facilitates maternal behavior, in part, by enhancing activity of three hormones. Name these hormones. 

Definition
Oxytocin, prolactin, and estradial.
Term
  1. Which brain system in the brain is involved in maternal behavior—it’s important for motivation and maternal memory?
Definition
(hint: it is involved in all motivated behaviors) Mesolimbic dopamine system.
Term
What exactly do hormones do?

Definition
They alter the activity in various brain areas to change the way they respond to various stimuli.
Term
How do hormones affect behavior?
Do they cause behavior? 
Definition

They influence behavior.

 

no 

Term
  1. Feelings are associated with physiological arousal. What does this mean? (hint: think stress/emotional response)
Definition
People who experience feelings associated with physiological arousal experience emotions more intensely, and they experience aspects of emotions beyond cognitive definition.
Term
  1. What is the James-Lange theory? (Note: discuss how you get from a stimulus to arousal and subjective emotional experience; describe the series of events)

Definition
Autonomic arousal and skeletal actions come before feeling

“I experience fear because I run away, i.e., my feelings are aroused by my actions.”

Cognitive awareness is separate

brain can categorize events as pleasant or unpleasant as quickly as 120 ms

Series of events:

Individual responds to stimulus

Perception leads to action & autonomic activation

Arousal and actions lead to feeling aspect of emotion

Term
  1. Which system in the brain is important for emotions? (hint: this system is made up of multiple subcortical structures; we’ve discussed it in class numerous times)
Definition
Limbic System
Term
  1. Is emotional information processes differently by each hemisphere?
Definition
Yes
Term
  1. What is the behavioral activation system? Behavioral inhibition system?

Definition
Behavioral Activation System (BAS): associated with activity of the left hemisphere (frontal & temporal regions)

Low autonomic arousal

Stimulates approach behaviors (happiness or anger)

Behavioral Inhibition System (BIS): associated with activity of the right hemisphere (frontal & temporal regions)

Increases attention and arousal

Inhibits actions

Stimulates fear and disgust

Term
  1. Which neurotransmitter is involved in aggressive behavior? Describe its role in aggression. (Note: mention how different levels of serotonin affect aggressive behavior)
Definition
Serotonin, when levels are decreased, it can increase aggression
Term
  1. What is fear? Anxiety?

Definition
Fear is associated with a tendency to escape from a threat

Anxiety is a general sense that something dangerous might occur

Term
  1. Which area of the brain is involved in generating a fear response?
Definition
Amgydala
Term
  1. What are the effects on behavior of amygdala damage in monkeys?
Definition
they are tame and placid
Term
  1. What are the effects on social judgment of amygdala damage in humans? What are some other effects of amygdala damage on processing emotional information?
Definition
They regarded all faces as equally trustworthy. They have trouble recognizing emotions.
Term
  1. What is stress according to Hans Selye?
Definition
stress is the nonspecific response of the body to any demand made upon it
Term
  1. How does the body respond to stress? What did Selye call the body’s response to stress?
Definition
Any threat to the body activates a generalized response to stress called the general adaptation syndrome
Term
  1. Describe the three stages of this response.

Definition
Alarm stage: increased activity of sympathetic nervous system (SNS)

Resistance stage: SNS activity decreases,; adrenal cortex secretes cortisol and other

Exhaustion stage: individual is tired, inactive, and vulnerable because the nervous system and immune systems have little energy

Term
  1. What is the HPA axis? This axis is made up of various structures; how do they communication with each other (is it paracrine or endocrine communication)? What activates this axis?

Definition
Comprises the Hypothalamus, pituitary gland, adrenal cortex

Hypothalamus makes CRH à Pituitary makes ACTH adrenal secretes cortisol à increase in blood sugar & metabolism

Activated w/ prolonged stressors

Beneficial in the short-term; detrimental in the long-term

Endocrine system.


 

Term
  1. Is activation of this axis beneficial or detrimental to our health? Which hormones are released during the stress response? Describe the effects of a prolonged activation of this axis? (Note: make sure to describe the effects of a prolonged increase in the major stress hormone)
Definition
Beneficial in the short-term; detrimental in the long-term
Flashbacks and nightmares about event

Avoidance of reminders of event

Exaggerated arousal in response to noises, other stimuli

Term
  1. Which area of the brain is responsive to cortisol? In fact, high levels of cortisol can damage neurons in this structure. (hint: it is involved in memory and it is smaller in people who suffer from PTSD)
Definition
hippocampus
Term
What are cytokines?
Definition
Cytokines: chemicals released from T-cells to fight infection & to communicate w/ brain à alter behavior
Term
Which cells produce and release cytokines?
Definition
T-cells
Term
What are the physiological effects of increased cytokine levels in the brain?
Definition
alters behaviors
Term

1.      What is learning? Memory?

Definition
Learning: acquisition of information

Memory: storage and retrieval of information

Term
Working memory?
Definition
the way we store information while we are working with or attending to it
Term
Declarative Memory:
Definition
ability to state a memory in words
Term

Episodic memory:

Definition
memories of single events
Term

 Procedural memory:

Definition
development of motor skills and responses
Term
Explicit memory:
Definition
deliberate recall of information that one recognizes as a memory
Term

 

Implicit memory:

Definition
influence of a recent experience on behavior, without necessarily realizing that one is using memory
Term

Priming?

Definition
Priming: a type of implicit memory; seeing or hearing words temporarily increases one’s probability of using them
Term

Consolidation:

Definition
short-term memories à long-term memories
Term
Anterograde amnesia?
Definition
memory loss for events that happened after brain damage
Term
retrograde amnesia  
Definition
inability to recall memories from the past.
Term

1.      Which area of the brain is important for working memory?

Definition
Prefrontal cortex
Term

1.      Describe the role of the hippocampus in learning and memory? Where is this structure located? (Note: describe the role of the hippocampus in the different types of memory—e.g., declarative, explicit, spatial, configural, implicit, and any others mentioned in the textbook; also go over the effects of hippocampal damage on patient HM)

 

Definition
Some support for critical role in declarative, explicit memory

true for H.M.

monkeys with damage are impaired in delayed matching (or non-matching) to sample task

but performs well if task always uses same objects

rats with damage have difficulty in learning correct temporal sequence for reward

Term

1.      What is a Hebbian synapse?

Definition
D.O. Hebb proposed that when an axon successfully stimulates a cell it will be even more successful in the future
Term
What is long-term potentiation? 
Definition
- Learning depends on some change at the synaptic level
Term
Specificity? -
Definition
only active synapses become strengthened
Term
Cooperativity?
Definition
- nearly simultaneous stimulation by two or more axons results in LTP
Term
Associativity?
Definition
- pairing a weak input with a strong input enhances later response to the weak input
Term
Long-term depression? -
Definition
prolonged decrease in response to a synaptic input where two or more axons have been active together at 1-4 times per second (low frequency stimulation)
Term

1.      Describe LTP in the hippocampus. LTP depends on changes at synapses. Describe these changes. (Note: define/describe AMPA receptors and NMDA receptors)

Definition
a burst of stimulation from axons, e.g., 100 excitations per second for 1-4 seconds onto dendrites results in potentiated synapses for minutes, days or weeks
Term

1.      Most of the changes associated with LTP take place in the postsynaptic neuron. Does that mean that there are no changes at the presynaptic level? (hint: what is a retrograde transmitter?)

Definition
stimulation of the postsynaptic cell releases a retrograde transmitter that feeds back to presynaptic cell

increases presynaptic release of neurotransmitter and production of GAP-43, facilitating growth of axons

Term
What happens if you block LTP with a drug? 
What happens if you facilitate LTP with a drug? 
Definition

learning is decreased

learning is facilitated 

Term
What is a commissure?
Definition
– smaller axons that connect the two hemispheres
Term
The corpus callosum?
Definition
- very thick bundle of nerve fibers containing both myelinated and unmyelinated axons; connects the right and left hemispheres
Term
Anterior commissure?
Definition
- a bundle of white fibers, connecting the two cerebral hemispheres across the middle line, and placed in front of the columns of the fornix
Term

1.      What is a split-brain procedure? Describe some of the behaviors displayed by a split-brain patient shortly after the procedure.

Definition
When the corpus callosum of an individual is severed, leaving a split brain, the two hemispheres cannot communicate
Term

1.      What is epilepsy? What causes epilepsy? What is a focus?

Definition
a common chronic neurological disorder that is characterized by recurrent unprovoked seizures. These seizures are transient signs and/or symptoms due to abnormal, excessive or synchronous neuronal activity in the brain. A focus is a place where the seizure originates.
Term

1.      Describe hemispheric specializations. What is lateralization? Which hemisphere is dominant for recognizing emotions in others? Which hemisphere is important for language?

Definition
Left controls right side/ Right controls left
The left hemisphere is specialized for language from the start in most people.

Right hemisphere is dominant for recognizing emotions in others

Term

1.      What is the planum temporale and where is it located?

Definition
Area of the temporal cortex that for most people is larger in the left hemisphere than in the right hemisphere.
Term

1.      What is Broca’s Aphasia? Wernicke’s Aphasia?

Definition
Loss of fluent speech and impaired use and understanding of prepositions, word endings, and other grammatical devices. Wernicke’s Aphasia? Poor language comprehension and great difficulty remembering the names of objects
Term

1.      Kinetic energy:

Definition
motion, capacity of doing work directly
Term

Potential energy:

Definition
the energy an object posesses because of it’s position, condition,     or composition
Term
Electric current:
Definition
represents transfer of
Term

Ion:

Definition
an atom or group of atoms that carry a charge
Term

Cations:

Definition
ions that have a positive charge
Term
Anions:
Definition
ions that have a negative charge
Term
What is a membrane potential?

Definition
electrical potential, or voltage, across the membrane
Term
Resting potential?

Definition
the resting potential is the result of negatively charged proteins in the cell, around -70mV.
Term
How and why does a neuron expend energy to maintain the resting potential?

Definition
A neuron stays at resting potential so it does not depolarize. The membrane is selectively permeable, and only allows large, charged particles through the potassium membrane/potassium sodium pump. The cell cannot depolarize because it prepares the neuron to respond rapidly to a stimulus (bow and arrow)
Term

1.      What causes the massive depolarization that occurs during an action potential?

Definition
an increased charge inside the cell.
Term
What happens at the peak of the action potential?

Definition
At the peak of the action potential, the potassium is released through ion channels that open once the ToE is reached.
Term

1.      During an action potential, what must occur to hyperpolarize the cell and bring it back to its resting potential?

Definition
the number of sodium ions must increase
Term
What is a concentration gradient?

         
Definition
the difference in distribution of ions across the membrane
Term
Electrical gradient?

Definition
A difference in electrical charge between the inside and outside of a cell
Term

1.      Describe the forces acting on sodium (Na+) and potassium (K+) ions.

              

Definition
Na+ is 10x greater outside

                K+ is 20x greater inside

Term
  1. What is a synapse? What is the name of a cell that transmits a signal to another cell? What is the name of the cell that receives information?
Definition
The gap between two neurons. Presynaptic cell. Postsynaptic cell
Term
Where are smaller neurotransmitters synthesized? 
Definition
Presynaptic terminal
Term
Larger neurotransmitters (peptides)? 
Definition
Endoplasmic reticulum
Term
Which ion is required for the release of neurotransmitter from the terminals and into the synaptic cleft?
Definition
calcium
Term
What are ionotropic effects?
Definition
ionotropic effect: gate opens and permits entry of an ion within a few ms; rapid effect; short lived (last only about 20 ms)
Term
Metabotropic effects?
Definition
metabotropic effect: initiates a sequence of metabolic reactions; slower effect (may take 30 ms or more to observe intracellular effects); long lasting (seconds, hours, or longer)
Term
Compare and contrast these effects (ionotropic vs. metatropic). For example, do both effects involve neurotransmitters and receptors? 
Definition
Yes, the only difference is how fast the permission is granted for a neurotransmitter, and how long the effects last
Term
  1. What is bulimia nervosa?
Definition
condition in which people alternate between extreme dieting and binges of overeating
Term
  1. How is bulimia similar to drug addiction?
Definition
Eating tasty foods activates the mesolimbic dopamine system, the same system involved in drug use. Drug addicts who cannot get drugs sometimes overeat as a substitute. A cycle of food deprivation and overeating stimulates brain’s reinforcement areas in much the same way that drug deprivation followed by drug use does.
Term
  1. In one experiment, rats were food deprived for 12 hours a day and then offered a solution of glucose. How did food deprivation affect feeding behavior in these rats?
Definition
The rats would do nearly anything for the glucose solution
Term
Is it possible for rats to develop a sugar addiction?
Definition
  yes
Term
Define substance abuse : 
Definition
a maladaptive pattern of substance use leading to clinically significant impairment or distress. (DSM IV)
Term
drug addiction:

Definition
when a substance of abuse dominates the person’s life. It is also known as substance dependence.
Term
Where in the brain does addiction happen?
Definition
Mesolimbic Dopamine System
Term
Which neurotransmitter is involved in addiction?
Definition
Dopamine
Term
  1. Is dopamine involved in other behaviors?
Definition
Yes
Term
  1. What do all addictive substances have in common 
Definition
(hint: think dopamine)? They stimulate the Mesolimbic Dopamine System
Term
  1. Olds and Milner conducted a few experiments showing that rats will press a lever for electrical stimulation of various areas of the brain. What do all of these areas have in common?
    Why would a rat press the lever as often as 2000 times per hour?
Definition

– they release dopamine in the nucleus accumbens

 

 

– to stimulate the release of dopamine in the brain, it is very rewarding

Term
What are some of the behavioral effects of stimulants?
Definition
hallucinations and delusions
Term
Why are psychostimulants (and most drugs of abuse) so addictive
Definition
– they stimulate the reward system, and people develop a wanting for that release of dopamine
Term
Do drugs of abuse elicit the same response after repeated use? -
Definition
no
Term
What is sensitization?
Definition
An increase in drug effect with repeated administration
Term
If someone repeatedly uses a drug like cocaine, how does that affect the brain’s reaction to the drug in the future? 
Definition
– it will react quicker
Term
  1. What is tolerance? -
Definition
A decrease in drug effect with repeated administration
Term
  1. Although many motivated behaviors that are pleasurable activate dopamine systems in the brain, other behaviors that do not provide joy also activate these same dopamine systems. What accounts for the fact that drug addicts continue to engage in drug seeking behavior even though the drug no longer provides pleasure? 
Definition
(hint: Berridge and Robinson proposed a hypothesis regarding this phenomenon) a physiological addiction
Term
What is depression? 
Definition
A mood disorder characterized by sadness, lack of energy, suicidal thoughts, sleep deprivation, and feelings of hopelessness
Term
What are SSRIs and how do they alter synaptic activity (identify the neurotransmitter involved)?
Definition
Selective Serontonin Reuptake Inhibitors. They keep dopamine in the synapse, and no not pick them back up
Term
Are the effects of SSRIs on synaptic activity quick or do they take weeks to occur?
Definition
Very quick
Term
Are the effects of SSRIs on behavior quick or do they take weeks to occur? 
Definition
It takes weeks
Term
Which hormone may be involved in triggering a depressive episode?
Definition
Cortisol
Term
What is Schizophrenia?
Definition
disorder characterized by deteriorating ability to function in everyday life and some combination of the following: hallucinations, delusions, thought disorder, alogia, affective flattening
Term
Describe the dopamine hypothesis of schizophrenia.
Definition
suggests that schizophrenia results from excess activity at dopamine synapses in certain areas of the brain.
Term
Is there evidence supporting this hypothesis?
Definition
Yes, prolonged activity of dopamine at the synapse
Term
Is it accurate to say that dopamine is the only neurotransmitter involved in schizophrenia?
Definition
no
Term
Is there another neurotransmitter that may be involved in schizophrenia?
Definition
glutamate
Term
  1. Can stress have an effect on a rat’s response to cocaine?
Definition
increased sensitivity
Term
  1. Corticosterone is a type of glucocorticoid (stress hormone) in rats. Humans have another type of glucocorticoid called cortisol. In one experiment, researchers treated rats with an injection of corticosterone. Describe the effects of corticosterone on self administration to cocaine in rats.
Definition
It mimicked the effects of uncontrollable stress
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