NSB Final Exam

movements

contractions of our muscles that provide our primary means of interacting with the world

reflex

Descartes coined this term when someone immediately pulls their hand away from a fire

simple reflex arc

sensory neurons from our muscle spindles enters the spinal cord via the dorsal root ganglion and synapses directly onto a motor neuron which in turns synapses on to a muscle causing it to contract

electromyography (EMG)

shows that muscles in the legs adjust before making a lever press thus suggesting a motor plan

skeletal muscles

muscles that control the movement of the skeleton (core of the motor system)

proprioception

our brain/body’s ability to know about the position and movement of itself

muscle spindles

muscle receptors containing an intrafusal fiber that lie parallel to a muscle and tell the CNS when a muscle is stretched

Golgi tendon organ

a proprioceptor found in the tendon that alerts the CNS when the muscle is under tension

motor plan

a plan of action generated in the cortex in advance of the execution of a movement and relayed to our muscles via the spinal cord

primary motor cortex (M1)

organized proportionally by representation of the contralateral side of the body

paralysis

damage to pyramidal motor system

plegia

paralysis of major muscles (quadriplegia is paralysis of all four limbs)

paresis

weakening of muscles caused by damage to motor cortices (monoparesis is weakness in one limb)

apraxia

difficulty carrying out complex motor sequences despite no paresis or paralysis

extrapyramidal system

consists of several smaller motor systems that include the basal ganglia, red nucleus, subthalamic nucleus, substantia nigra and cerebellum

movement disorders

often impact extrapyramidal motor systems and alter the patients’ abilities to initiate or control movements

direct pathway

dopamine from the substantia nigra promotes movement by activating D1 receptors in the striatum

indirect pathway

dopamine from the substantia nigra blocks the ability of the indirect pathway to inhibit movement by activating D2 receptors in the striatum thus promoting movementand facilitating the direct pathway's effects.

dopamine acts as a

gate keeper to promote movement which is ultimately why its input to the basal ganglia is so important

Parkinson’s disease

neurodegenerative disease characterized by tremors at rest, bradykinesia, blank facial expression and abnormal movement due to the loss of dopaminergic neurons in the substantia nigra, leading to impaired movement control.

Huntington’s Disease

a neurodegenerative disease that produces hyperkinesia (excessive movement) along with coordination issues and eventually cognitive deficits that usually develops around midlife

pheromones

olfactory cues that

1. bodily secreted

2. detected by another individual

3. affect the neuroendocrine system

4. affect behavior

neuroendocrine system

a collection of glands, largely controlled by the hypothalamus to maintain homeostasis

hormones

chemical signals that travel in the blood and can impact neurons as well as other organs

peptide hormones

small proteins made up of strings of amino acids that typically bind a receptor

amine hormones

hormones composed from a single amino acid that typically bind a receptor

oxytocin and vasopressin

a small peptide hormone that is associated with numerous complex behaviors

oxytocin receptors (OTRS)

enhance the rewarding aspects of social interaction in prairie voles

activational effect

their presence transiently promotes certain behaviors

testosterone

modulates male mating behaviors via androgen receptors in mPOA

estrogen and progesterone

regulate female mating behaviors via VMH and PAG

general adaptation syndrome

describes how a body reacts to a stressor. has 3 stages

alarm stage

comprised of a shock phase and an antishock phase where norepinephrine and adrenaline signal the sympathetic nervous system

resistance stage

stress hormones flood the body mobilizing energy stores

recovery stage

once the stressor is eliminated the parasympathetic nervous system engages to promote recovery

stress

a physiological and psychological response to a change in the environment that often produces an elevated sense to tension or anxiety

autonomic nervous system is divided into

1. sympathetic nervous system - prepares body for action (fight or flight)

2. parasympathetic nervous system - prepared body to relax and recuperate (rest and digest)

adrenal gland

sits on top of the kidney and works in conjunction with the brain to coordinate the stress response

adrenal gland is divided into

• adrenal medulla- central portion of the adrenal gland, responsible for adrenaline release

• adrenal cortex- outer portion of the gland and further subdivided into

  • zona glomerulosa- outermost layer responsible for production of aldosterone

  • zona fasciculata- medial layer that produces glococorticoids like cortisol

  • zona reticularis- intermost layer that produces androgens, including dehydroepiandrosterone (DHEA) and androstenedione

corticotropin-relasing hormone (CRH)

chemical that is released after the hypothalamus receives input from various brain areas

cortisol

a steroid hormone and type of glucocorticoid that plays numerous roles in our physiology. primarily responsible for

1. gluconeogenesis- the production of glucose

2. suppressing bone growth

3. suppressing the immune system

4. regulating blood flow

   1. shaping the stress response

homeostasis

a concept that implies there is a single optimal value or set level by which an organism functions

allostasis

describes how your body adapts to varying demands. addendum to homeostasis hypothesis pioneered by Bruce McEwen

allostatic load

the difference between what your body is doing to adapt and the time it needs to fully recover

acute stress promotes

• faster heartbeat

• increased respiration

• eliminates urge to sleep

chronic stress promotes

• heart attack

• stroke

• diabetes

• chronic fatigue

• miscarriage

circadian rhythms

the most common biological rhythms lasting approximately 24 hours

• hormone levels

• body temp

• drug sensitivity

infradian rhythm

a rhythm that repeats less than once per day, i.e. menstrual cycle

ultradian rhythm

a rhythm that repeats multiple times in a 24 hr period, i.e. activity levels

zeitgebers

external cues like light. help entrain a biological rhythm to a particular event

free-running rhythm

in the absence of environmental cues like sun rise/set, the period drifts but the time spent awake and active stays roughly the same

REM sleep

appear awake, rapid eye movement but muscles stay relaxed

stage 3 sleep (slow wave sleep)

characterized by slow 1-4 Hz waves of brain activity called delta waves, generated by the basal forebrain

stage 2 sleep

defined by periodic bursts of activity called sleep spindles and K complexes

Sleep spindles

12-14 Hz bursts in activity

K complexes

sharp negative EEG potentials

stage 1

begin to nod off the rhythm of your neural activity changes adopting a regular oscillation of about 8-12 Hz known as an alpha rhythm

vertex spike

sharp-wave EEG pattern unique to Stage 1 sleep

pons

triggers REM sleep