Quiz #3 A&P

What are the stages of sleep?

1, 2, 3, 4, REM

What are two things that make processing scents different than other senses?

1. Processing is ipsilateral -- R nostril is connected to R hemisphere 2. Sensory afferents synapse in the cortex before the thalamus

How much of the direct motor pathways are meant for the trunk?

10%

What is the process of first, second, and third order neurons of the posterior column-medial lemniscus pathway?

1st order: ascend via posterior column of spinal cord + synapse w/ gracile (lower body) or cuneate (upper body) nucleus in medulla 2nd order: decussate + travel via medial lemniscus + synapse within thalamus 3rd order: neurons from thalamus synapse within sensory cortex

What is the process of first, second, and third order neurons of the spinocerebellar pathway?

1st order: synapse at dorsal root. ganglion of spinal cord 2nd order: dorsal spinocerebellar tract is for muscle spindle signals. ventral spinocerebellar tract is mostly for golgi tendon organs. ipsilateral = no decussation 3rd order: no 3rd order neurons bc ipsilateral

What is the process of first, second, and third order neurons of the anterolateral (spinothalamic) pathway?

1st order: synapse w/ second order neurons within spinal cord at level of entry 2nd order: decussate within spinal cord + travel via anterior + lateral tracts to synapse within thalamus 3rd order: from thalamus synapse within sensory cortex

What is the process of first, second, and third order neurons of the trigeminothalamic pathway?

1st order: trigeminal nerve synapse with second order neurons in pons or brainstem 2nd order: decussate at level of synapse + travel via trigeminothalamic tract to synapse within thalamus 3rd order: from thalamus synapse with sensory cortex

How much of the direct motor pathways are meant for the limbs (arms & legs)?

90%

What is CPAP used for?

Continuous positive airway pressure therapy (CPAP ) uses a machine to help a person who has obstructive sleep apnea (OSA) breathe more easily during sleep. A CPAP machine increases air pressure in your throat so that your airway doesn't collapse when you breathe in.

What brings us into a conscious state?

Activation of RAS (also maintains alertness)

How is "bitter taste" detected?

Blockage of K+ channels or activation of G protein coupled receptors; bitter receptor agonists often alkaloid-type molecules

How is "sweet taste" detected?

By G(s) protein coupled receptors that generate cAMP that opens depolarizing ion channels. Artificial sweeteners also activate G(q) receptors similar to those of bitter taste cells

What does the basal nuclei circuit of the somatic motor pathways do?

Fine tune initiation and termination of voluntary movements.

Where does sensory perception begin?

First order neurons

What are the two types of paralysis? What are the differences?

Flaccid- failure of the muscle to contract Spastic- uncontrolled contraction

Where on the tongue does the Facial nerve innervate?

Fungiform & Filiform papilla

What are the three families of G protein? What do they do?

G(s)a - signals through cAMP G(i)a - inhibits cAMP signaling G(q)a - signals through Ca++

Where on the tongue does the Glossopharyngeal nerve innervate?

Lingual tonsil + vallate papilla

What is the role of interneurons of the cerebral cortex?

Link sensory + motor afferents, and associated areas of brain.

What are the four neural circuits of the somatic motor pathways?

Local circuit, upper motor neurons, basal nuclei, and cerebellar neurons

What does the local circuit of the somatic motor pathways do?

Located closest to lower motor neuron cell bodies; coordinate rhythmic movements

Where are photoreceptors of human eye located?

Located near rear of retina + pointed towards + attached to pigmented epithelium

What is olfactory adapatation?

Loss of receptor activation following prolonged exposure to a particular odorant

What are the two functions of tears?

Maintain moisture & provide immunological barrier

How is "umami taste" detected?

Savory flavor produced by amino acids (glutamate) detected by G protein coupled receptor. MSG activates umami receptor.

How does salt enhance flavors?

Selectively suppressing signals from bitter receptors

Where do second order neurons arise and terminate?

Sensory centers of the brain stem and terminate in the the thalamus

What is integration?

Process by which brain processes multiple sensory inputs to produce a response. It is basis of learning and decision-making

What muscles are responsible for pupil dilation? What causes pupils to dilate?

Radial muscles of iris contract; dim light

What characterizes REM sleep?

Rapid eye movement; where most dreams occur

How are gustatory receptor cells distinct from the associated sensory afferent?

Receptor potential leads to neurotransmitter release from the receptor cell

What involuntary centers of the brain activate balancing motions to ensure successful movement?

Red nucleus, vestibular nuclei, and reticular formation

What does the reticulospinal tract do?

Regulate posture + muscle tone

How do cephalopod retinas differ fro humans?

Retinas are configured in opposite orientation w/ photoreceptors pointed towards incoming light

What are the effects of sleep deprivation on the pancreas?

Risk of T2 diabetes

What are the four indirect motor pathways?

Rubrospinal tract, vestibulospinal tract, reticulospinal tract, and tectospinal tract

What happens to vision when you have a detached retina?

Vision becomes distorted with the ruffles of the retina

What is the composition of human tears?

Water, electrolytes, proteins, lipids, mucins, defensins, collectins, other small molecules

What is proprioception?

awareness of ones position in space and the relative position of the limbs

What characterizes deeper sleep?

brain activity occasionally increases; most of sleep is in this phase

How is "salty taste" detected?

by Na+ channel; depolarizes the receptor cells

What do third order neurons do?

carries the sensory signal the rest of the way from the thalamus to the sensory region of the cerebral cortex

What does the muscle spindle detect?

changes in muscle lengthening

What are cataracts?

clouding of the lens of the eye

what are joint kinesthetic receptors? What information do they provide?

collection of mechanoreceptors associated with joint issues; provide information on joint angle

What is a circadian rhythm?

cycle of sleeping and waking governed, in part, by melatonin

What causes flaccid paralysis?

damage to lower motor neurons

What damage results in an ulnar claw?

damage to motor neuron of ulnar nerve. 4th/5th digits can't be extended

What causes spastic paralysis?

damage to upper motor neurons

What is macular degeneration?

death of pigmented cells

How do we create new connections between neurons?

deliberate practice

What characterizes light sleep?

easy arousal by external stimuli

What does the hyaloid canal do in the eye?

expand + contract for pressure changes

What does it mean to say an odorant is stochastic?

for a molecule to be detected, it must hit the receptor that recognizes it, which is random

What papillae contain taste buds?

fungiform, vallate, foliate

What is the vitreous humor?

gel-like substance behind the lens in the posterior cavity; it presses against the retina and keeps it attached to pigment epithelium of choroid

What are other effects of sleep deprivation?

growth suppression, risk of obesity, decreased temperature

What are dreams?

imagined experiences produced by the brain mainly during REM sleep

What are the 3 types of memory?

immediate, short term, long term

What is insomnia?

inability to enter or remain in a state of sleep

What is anterograde amnesia?

inability to form new memories for long term. (damage to mammillary bodies)

What are the effects of sleep deprivation on the heart?

increased HR variability, Risk of heart disease

What does the presence of white blood cells in tears indicate?

infection

What systems are involved in proprioception?

inner ear organs, eyes, and mechanoreceptors of muscles, joints, and tendons are integrated in the cerebellum + motor centers of the cerebrum + brainstem

What is obstructive sleep apnea? What are common causes?

interruption of breathing during sleep caused by blocked airways; excess body weight, deviated nasal septum, allergies, and large tonsils or tongue

What is central sleep apnea?

interruption of breathing during sleep caused by problems in the Respiratory control centers of the brain stem.

What is the flow of tears?

lacrimal gland --> lacrimal ducts --> superior/inferior lacrimal canal --> lacrimal sac --> nasolacrimal duct --> nasal cavity

What is amnesia?

loss of memory

What is retrograde amnesia?

memories formed prior to injury are lost; when memory returns, memories formed closest to accident are recovered later

What is an odor threshold?

minimum concentration required to detect a molecule

Where does voluntary movement originate?

motor cortex with guidance of premotor cortex

How do they eyes process so much sensory information?

multiple layers of cells + synaptic layers to process information as it comes in; some being processed as new info is taken in

What is the structure of a taste bud?

multiple taste/gustatory receptor cells that align in a pit with a single opening (taste pore)

What does the golgi tendon organ detect?

muscle tension

What is the agonist muscle?

muscle that contracts to produce a movement

What is the antagonist muscle?

muscle that relaxes to produce a movement

Loss of sensation in any of the proprioception organs can cause what?

negatively impact balance and movement

Where are olfactory receptors expressed?

neurons

What is the posterior column-medial lemniscus pathway?

non-painful pathway for touch, pressure, vibration, & conscious proprioception

What is retinal neovascularization?

overgrowth of blood vessels

What is the anterolateral (spinothalamic) pathway?

painful pathway for pain, temperature, itch, and tickle

What is REM sleep also referred to as?

paradoxical sleep

What is deliberate practice?

practicing with intention, motivation, repetition, and improvement

What is memory?

process of storing information. memories are encoded in the physical connections between neurons in the brain

What does olfactory stimulation do?

produces receptor potential that leads to action potentials directly

What is immediate memory?

recall ongoing experiences -- lasts a few seconds

What is short term memory?

recall specific, recently acquired information. without repetition, information may be discarded

What is the primary mechanism for olfactory adaptation?

receptor internalization

What does it mean to say that the cortex is plastic?

relative size of each region can be changed by numbers of inputs. ex: ppl who read braille

What is a simple scent?

singular compound that makes one scent

Where do first order neurons synapse?

spinal cord or brainstem

What is consciousness?

state of being responsive to external stimuli

What are the basal cells?

stem cells that replace taste cells every 7 to 10 days

What is long term memory?

storage of information for days and years. repetition of information enters into long term memory via the process of memory consolidation

How is cataracts treated?

surgery

What do filiform papillae have in place of taste buds?

tactile receptors

What is learning?

the acquisition of new knowledge/skills

What is the aqueous humor?

the clear fluid filling the space in the front of the eyeball between the lens and the cornea (anterior cavity); has similar composition to blood plasma

Where is the retina located?

the retina extends from the posterior surface of the eyeball to about 3/4 of the eyeballs inner surface

How is spicy "taste" detected?

thermally gated nociceptors in the tongue. Signals conveyed via trigeminal nerve to pain, not taste, centers in the brain

What does the vestibulospinal tract do?

uses positional information from vestibular organs to maintain balance

How many functional/nonfunctional OR genes do humans have?

~400 functional and at least that many nonfunctional

What does the tectospinal tract do?

Turns head, eyes, and trunk towards novel auditory/visual stimuli

What is narcolepsy?

A sleep disorder characterized by uncontrollable sleep attacks and day-time drowsiness. (Can also be paired with cataplexy -- sudden loss of skeletal muscle tone).

What is the golgi tendon organ?

A stretch receptor found in tendons and ligaments

What is the muscle spindle?

A type of stretch receptor embedded in skeletal muscle

What does the cerebellar neuron circuit of the somatic motor pathways do?

Assess differences between intended and actual movements and provide adjustments

What part of they eye controls the shape of the lens?

Ciliary body (ciliary muscle + ciliary process)

What muscles are responsible for pupil constriction? What causes pupils to constrict?

Circular muscles of iris contract; bright light

What are treatments for insomnia?

Cognitive behavioral therapy (relaxation, sleep restriction, light exposure therapy), prescription & OTC sleep aids, melatonin

What system is responsible for pupil dilation? Parasympathetic or sympathetic? via what?

Sympathetic; sympathetic chain via superior cervical ganglion

What is the function of the RAS system?

Taking sensory input and making output

What are the most common forms of narcolepsy caused by?

Death of neurons that produce neurotransmitter hypocretin (orexin)

What are psychological causes of insomnia?

Depression, anxiety, emotional trauma

How is "sour taste" detected?

Detection of H+ because it can enter cells through passive channels but does not typically produce sufficient depolarization. Instead, decreased pH closes acid sensitive K+ channels + reduced potassium outflow depolarizes cells

What is the corticobulbar pathway?

Direct motor pathway responsible for the head of the body that travels from the motor cortex --> upper motor neuron --> corticobulbar tract --> lower motor neuron (pons) to skeletal muscles of facial expression OR lower motor neuron to skeletal muscles of tongue

What is the lateral corticospinal pathway? Where does it decussate?

Direct motor pathway that is responsible for the limbs that travels from the motor cortex --> upper motor nueron --> medullary pyramids --> lateral corticospinal tract of spinal cord; it decussates at the medullary pyramids

What is the anterior corticospinal pathway? Where does it decussate?

Direct motor pathway that is responsible for the trunk of the body that travels from the motor cortex --> upper motor neuron --> anterior corticospinal tract --> lower motor neuron; Decussates at level of exit

What can help estimate sleep stage?

EEG, HR variability, + movement detection

Where on the tongue does the vagus nerve innervate?

Epiglottis

T/F: Each OR can be activated by many molecules

False; Each OR is activated by a single molecule or a few very similar molecules **Molecules that activate same receptor perceived as same odor**

T/F: They eye forms as a part of the PNS.

False; the eye forms as a part of the CNS

What are the effects of sleep deprivation on the immune system?

Impaired immune system

What are the effects of sleep deprivation on the muscular system?

Increased reaction time, decreased accuracy, tremors, aches

What are indirect motor pathways responsible for?

Involuntary and unconscious motor functions

What are the effects of sleep deprivation on the brain?

Irritability, cognitive impairment, memory lapses or loss, impaired moral judgement, severe yawning, hallucinations, ADHD symptoms

What part of the eye is responsible for mucus formation?

Lacrimal caruncle

What characterizes deep sleep?

Largely unresponsive to external stimuli. Highly disoriented if awoken during this phase

What are the 3 direct motor pathways?

Lateral corticospinal pathway, anterior corticospinal pathway, and the corticobulbar pathway

What part of the early eyes forms the lens?

Lens placode

What is a complex scent?

Multiple compounds of combined odorants to make one scent of multiple scents.

How does mucus secretion contribute to olfaction?

Olfaction relies on moisture to function, dry olfactory cells cant smell. Mucin glycoproteins pull in water to turn into thicker gel; mucus should be watery

What is the olfactory pathway?

Olfactory receptors, olfactory bulb, primary olfactory cortex (amygdala and hippocampus), thalamus, secondary olfactory cortex (orbitofrontal region)

What part of the eye contains the vessels + nerves?

Optic stalk

What system is responsible for pupil constriction? Parasympathetic or sympathetic? By what nerve?

Parasympathetic; oculomotor nerve via ciliary ganglion

What is the spinocerebellar pathway?

Pathway for proprioception involved in unconscious motor coordination

What is the trigeminothalamic pathway?

Pathway responsible for sensation from face, teeth, & tongue (except taste)

What is caused by the lack of photoreceptors in the optic disc?

Physiological blindspot

Where does the posterior column-medial lemniscus pathway crossover?

The brainstem

What causes the red pupil in people with albinism?

The lack of melanin pigment in the choroid + retina

Where is the entry point for the optic nerve + supporting blood vessels?

The optic disc

Where is the primary olfaction area?

The uncus

How do first order neurons detect the stimulus?

They're detected directly or activated by signals from a separate receptor cell

What does the upper motor neurons circuit of the somatic motor pathways do?

Those in cortex initiate voluntary movement; those in brainstem regulate muscle tone

What is the trade off for loss in olfaction?

Tri-color vision

Are normal circadian rhythms essential to health?

Yes

Do neuron regenerate at the olfactory level?

Yes; only here

What is sleep apnea?

a sleep disorder characterized by interruption of breathing during sleep

What does the rubrospinal tract do?

adjusts voluntary motor signals

What are somatic causes of insomnia?

allergies, infections, acid reflux, and chronic pain