red terms exam 3

the process by which the body acheives a stable, balanced internal environment. occurs through the maintenance of optimal set points

homeostasis

point at which a given physiological system functions best; maintain homeostasis

set point

the range within which a physiological system can function within the set zone

the range within which a physiological system can function

set zone

works like a thermostat – if a space is too cold, a thermostat will try to make it hotter and vice versa

homeostasis

Whatever is happening in a physiological system to cause it to deviate from the set point, homeostasis counteracts it by doing the opposite in order to find the set point again. This is called

negative feedback.

the process by which the body maintains an ideal temperature; can be behavioral (especially in reptiles since they have a low metabolism)

thermoregulation

For mammals, body temperature is maintained physiologically by utilizing the heat produced through

metabolism

temperature receptors can be found on

skin surfaces (externally) and brain (internally)

takes care of the physiological responses that raise body temp in response to cold, such as shivering and constriction of blood vessels; required by hypovelmic and osmotic thirst

preoptic area (POA) of the hypothalamus

heat generated through metabolic burn required for motion

shivering

reduced blood flow makes skin and fat more effective as insulation

Constriction of blood vessels in body’s exterior

is crucial for the behavioral regulation of temperature, such as seeking out sources of heat, increasing the surface area of the body that gets heat exposure (basking in the sun), etc

lateral hypothalamus

is evolutionarily ancient and seems to regulate similar homeostatic functions in multiple species

hypothalamus

is the motivational response to the fluid loss that is required by normal processes such as breathing, sweating, and urination; comes in two forms - osmotic and hypovelmic

thirst

This kind of thirst is triggered by an upswing in salt levels via urination (the kidneys retain salts) or salt consumption

Osmotic thirst

This kind of thirst is triggered even if salt concentrations do not change (caused by sweating)

Hypovolemic thirst

contain osmosensory neurons that detect changes in the concentration of salt in the cerebrospinal fluid of the ventricular system

circumventricular organs

When the fluid around the osmosensory neurons is too salty, they ____. When it is not salty enough, they ____.

shrink; swell

Shrinking opens mechanically-gated ion channels in the membranes of osmosensory neurons, swelling closes them; causes a generator potential that makes the osmosensory neuron more likely to fire an action potential

shrinking of osmosensory neurons

located in blood vessels of kidney and heart; monitor changes in blood volume by detecting when the walls of the blood vessels stretch or contract

baroreceptors

osmosensory neurons and baroreceptors reach the POA and activate it, causing _______

increased drinking behavior

triggers physiological responses by causing the release of the hormone vasopressin from the pituitary gland, telling the kidneys to retain water

POA

are those that the body cannot manufacture and must be obtained from diet. These include: glucose, tryptophan, omega-3, certain vitamins and minerals

essential nutrients

the primary sugar that your body uses for energy

glucose

hormone for when glucose levels in the blood rise; allows glucose to enter muscles and liver cells for use or to be converted into glycogen for short-term storage

Insulin

hormone that converts glycogen back into glucose when glucose levels fall

glucagon

for long-term storage; where glucose goes if the body has more than needed

adipose tissue

(inc/dec) in glycogen causes the body to convert fats back into glucose

decrease

a disease that results from a failure of insulin to allow glucose to be taken into cells

diabetes

Type-I diabetes is ‘juvenile-onset’ and occurs when the pancreas ____ making insulin; Type-II is ‘adult-onset’ and occurs when cells no longer respond to _____.

stop; insulin

too much glucose in the blood; can lead to HBP

hyperglycemia

your level of energy use when you are at rest. This energy goes to: heat production, maintenance of ion gradients (esp. in brain), life-sustaining cellular processes

basal metabolism

basal metabolism will decrease when energy intake decreases

metabolic adaptation

Hormones interact either directly or indirectly with the hypothalamus to produce

hunger

the motivational drive to eat

hunger

the feeling of being full/the absence of hunger

satiety

monitors the levels of various hunger and satiety-relevant hormones, which can activate one of two different types of neuron in the arcuate: POMC neurons, NPY neurons

arcuate nucleus

signal satiety when they are activated and thus inhibit hunger and feeding

POMC neurons

signal hunger when they are activated and thus promote feeding

NPY neurons

released from digestive organs in the absence of food in the gut; levels drop after eating; High levels activate NPY neurons and stimulate hunger

Ghrelin

released from the pancreas in response to food. High insulin levels inhibit NPY neurons, reducing hunger.

Insulin

released from fat cells; high levels both inhibit NPY neurons AND activates POMC neurons, reducing hunger and promoting satiety

leptin

released from digestive organs in the presence of food in the gut; stimulates insulin release from the pancreas. It also activates POMC neurons

glucagon-like peptide 1 (GLP-1)

is a GLP-1 receptor agonist. Marketed under the trade name Ozempic, it is a treatment for Type-II diabetes administered as a once-weekly injection. It is also being used as a weight-loss drug. It reduces appetite directly (by activating POMC neurons) and indirectly (via the effect of insulin on NPY cells)

Semaglutide

are processes in the brain that regulate pleasure and reward, influencing eating behavior and food preferences.

hedonic mechanisms

is a part of the basal ganglia that is involved in motivation in both humans and rats

nucleus accumbens (NAcc)

achieved through food engineering; the amount of an ingredient needed to make a food maximally delicious

bliss point

the more you eat of a specific food, the less you want it; you would probably refuse more savory food following your entrée, but you may be willing to have dessert

sensory specific satiety

Are fluctuations that occur over a roughly 24hour period

examples: sleep and wakefulness, hormonal concentrations in the blood; feeding

circadian rhythms

sleep ‘debt’ builds up the longer you’re awake and is alleviated by adequate sleep

process S, homeostatic need for sleep

multiple cognitive deficits, emotional instability, impaired motor coordination and reaction times comparable to intoxication

Immediate effects of sleep deprivation

depressed immune function, increased vulnerability to disease liability, neurological decline

Long-term sleep deprivation

sleep is governed by the 24-hour body clock, ensuring that sleep debt is paid on a regular basis and that sleep is timed in an adaptive way

Process C, circadian pacemaker

external cues that regulate the circadian rhythms, such as light and temperature.

zeitgebers

contains the circadian clock (which is a ~24 hour long molecular process that occurs within neurons in that structure)

suprachiasmatic nucleus of the hypothalamus (SCN)

releases the hormone melatonin at night in order to facilitate sleep

pineal gland

hormone released at night that facilitates sleep

melatonin

two proteins made by SCN that form a dimer

clock and cycle

Within ____ cells, Clock and Cycle proteins bind together to form a regulatory ___ that directly activates the transcription of period and cryptochrome genes. This activation initiates a self-sustaining feedback loop where the resulting gene products eventually inhibit their own production, driving the body's master ______.

is a technique that measures the combined activity of many neurons (i.e. brain waves) and can be used to differentiate the distinct stages of waking and sleep

EEG

Waking brain waves tend to be (high/low) frequency and (high/low) amplitude

high frequency and low amplitude

comes first and is divided into 3 phases with distinct brain-wave patterns.

Early stage: the heart rate slows and muscles relax

When awakened: people often deny that they were sleeping

Final stage (slow-wave sleep): involves high amplitude brain waves and (non-seizure) synchronization of activity across the cortex

non-REM sleep

brain wave activity is highly similar to activity observed during waking; darting movement of the eyes; complete loss of muscle tension; like to report dreaming

REM sleep

7-8 hours, 80% non-REM / 20% REM

healthy sleep

tends to occur earlier in the night; most restful and restorative; deepest phase of non-REM sleep; when growth hormones are released; memory storage from previous day

slow-wave sleep

allows migratory birds to remain partially conscious while also being partially asleep midflight

Some animals have developed the ability to sleep one brain hemisphere at a time

where orexin neurons project; located in hindbrain (pons); made up primarily of neurons that produce the neurotransmitter norepinephrine that mediates arousal; small in size but have widely-projected neurons

locus coeruleus

contains acetylcholine neurons—very important for attention

basal forebrain

neurons in this region do the opposite of orexin neurons – they release GABA onto neurons in the reticular formation, thus inhibiting it and decreasing wakefulness

ventrolateral preoptic area (VLPO)

is a disorder in which overwhelming sleepiness occurs very suddenly and unpredictably. Humans have been shown to possess reduced numbers of orexin neurons

Narcolepsy

is a brief inability to move after waking

sleep paralysis

is responsible for the loss of muscle tension that occurs during sleep

dorsal pons

opposite problem of sleep paralysis; no loss of muscle tension during REM sleep. Individuals with this issue can act out there dreams in the real world while remaining asleep

REM behavior disorder

locationist definition of emotion

A perspective suggesting that specific emotions are associated with distinct locations or regions in the brain, indicating that emotions arise from particular neural circuits.

removal of the monkey amygdala causes a series of bizarre emotional and motivational responses

o Reduced fear and aggression – monkeys became strangely docile

o Strange food consumption behavior – non-food items consumed

Klüver-Bucy Syndrome

has a rare disease that destroyed her amygdala; startle response is extremely limited; overly trusting (doesn’t show suspicion or fear)

Patient SM

Evidence from studies of _____ demonstrates that a rat with lesions of the auditory cortex can still show fear in response to a tone that predicts a mild electrical shock

fear conditioning

can produce a disorder called abulia if damaged

anterior cingulate cortex (ACC)

create subtle movements in the skin of the face •(such as wrinkling your nose)

Superficial facial muscles

create larger movements (such as opening your mouth)

Deep facial muscles

cranial nerves that control facial muscles

facial nerve and trigeminal nerve

breakdown of expressions that result from the contraction of a specific pattern of facial muscles

action units

the physiological response to aversive or threatening stimuli

stress

Stress has a strong hormonal component that is regulated by the; controls the release of cortisol

hypothalamus-pituitary-adrenal axis (HPA)

stress-hormone; partial metabolic hormone that inc. glucose levels in the blood

cortisol

hypothalamic neurosecretory cells

cells in the hypothalamus that synthesize and secrete hormones into the bloodstream, regulating various physiological responses.

released by neurosecretary cells into the portal vein; travels a short distance to the pituitary gland, causing the release of the adrenocorticotropic hormone (ACTH) into the blood stream

corticotropin-releasing factor (CRF)

released by CRF/pituitary gland; travels to adrenal gland and stimulates cortisol release

adrenocorticotropic hormone (ACTH)

a regulatory mechanism that controls the release of cortisol by inhibiting further secretion of CRF and ACTH when cortisol levels are sufficient.

HPA Axis negative feedback loop

activated by stress; increases the availability of glucose while also increasing utilization of that energy by muscles (fight-or-flight); causes release of epinephrine (adrenaline) from the adrenal gland

sympathetic NS

rest and digest; inhibited by the activation of sympathetic NS

parasympathetic NS

acute stress

A short-term response to perceived threats that activates the body's stress response system

chronic stress

A long-term response to ongoing stressors that can lead to adverse health effects, including anxiety, depression, and physical health issues.

Subjects (such as rats) are paired so that one, the master, controls what happens to both itself and its partner, the yoke. In a common variation of this, the master turns a wheel to determine the duration of shock for itself and its yoked partner

yoked control design

A behavioral phenomenon where an individual learns to feel powerless and stop trying to escape from stressful situations after repeated failures to do so. This often results from exposure to uncontrollable and adverse events.

learned helplessness

activated by control over stressors; can inhibit activity in regions like the amygdala and thus dial down the stress response

medial prefrontal cortex (mPFC)

baseline affective/emotional state that persist across situations

mood

disruptions or distortions in mood that significantly impair normal life activity

Mood disorders

symptoms include persistent feelings of despair, anhedonia (inability to take pleasure in previously pleasurable things), disruptions in sleep and weight, extreme pessimism and suicidality

depression