psy 260 exam 2 Flashcards
types of muscles
- skeletal
- smooth
- cardiac
skeletal muscles
voluntary muscles - motor
smooth muscles
glands and organ muscles
cardiac muscles
heart
where do motor neurons send axons to ?
out of the ventral root
Proprioceptors
Awareness of the in muscles and joints ; sensory receptors in the muscle and joints
Golgi tendon
senses muscle tension thus relaxing the muscle
do reflexes require the brain to activate? And they travel through the?
Reflexes do not require the brain as it first travels through the spinal cord to move from “danger” and then it goes to the brain to process as pain “ow”
how do reflexes thus occur?
Muscle spindle senses stretch, causing the muscle to contract
Myasthenia Gravis
(severe muscle weakness) immune system attacks cholinergic receptors in the muscle
how is Myasthenia Gravis treated?
Treated with drugs that block AChE (AChE breaks down acetylcholine) meaning more acetylcholine in the synapse to be therapeutic with this condition
the action of blocking AChE to allow more acetylcholine in the synapse ; is it an agonist or antagonist action?
Antagonist
what are the most common spinal cord injuries ?
vehicular crashes and falls
can we heal from spinal cord injuries?
yes, the time window to do surgery for a spinal cord injury’s is essential for recovery
other ways to supplement healing would be by our own body and efforts :
- Schwann cells create a physical bridge for reconnecting to the target issue
- astrocytes create scar tissue around injury
- Transplantation of schwann cells or olfactory ensheathing cells; transplanting fetal tissue or stem cells to heal injury
- physical therapy
The cortex
- Motor planning in the prefrontal cortex
- Movement selection and initiation
The cerebellum
- Controls Ballistic movements are movements that, once triggered, cannot be stopped
- Sequence and timing of movement
what happens when the cerebellum is damaged?
leads to problems with balance, difficulty with motor learning and challenges with timing and sequencing of movements
basal ganglia
- Made of the caudate (striatum), putamen, and globus pallidus
- Connections to the motor cortical areas
- Manages motor function
- Can excite or inhibit movement
a disorder in the basal ganglia would be?
Huntington’s and Parkinson’s disease
The somatotopic organization controls what side of the body?
The contralateral body ;opposite side
What is Huntington’s disease ?
The degeneration of the basal ganglia due to a genetic mutation of the dominant gene on chromosome 4
Why are some signs of Huntington’s disease appear early on some individuals and some later?
Excessive number of trinucleotide repeats (CAG) ; meaning the greater number of repeats, the earlier the onset of symptoms will appear
What do you see in a patient with Huntington’s disease?
Eventual slowness of movement, chorea (jerking/excessive movements) immobility, and death
Nancy Wexler
Founded the genetic test to determine if the individual is a carrier for the Huntington’s disease mutation
What is Parkinson’s Disease ?
Degeneration of striatum (basal ganglia)causing a loss of dopamine leading to the reduction and slowness in movement
How does Parkinson’s Disease look in a patient?
Difficulty and slowness of movement
Resting tremor
Muscle rigidity
Loss of facial muscle tone
cognitive impairments
Depression
Treatments for Parkinson’s disease?
- L-dopa → precursor of dopamine
- Fetal tissue transplantation
- Stem cell transplantation
- Surgeries to destroy certain parts of the basal ganglia that - are inhibitory versus excitatory
- Changing the activity of the basal ganglia by giving deep brain stimulation
Why is L-dopa a controversial treatment?
Can stop working or leads to excessive movements; too much or too little dopamine is bad
Circadian rhythms
(daily rhythm) ; The suprachiasmatic nucleus (SCN) of the hypothalamus has intrinsic rhythms that allow them to have the ability to keep time
free running clock
about a 24.5 - 25 hour cycle
why would we be out of sync ?
- jet lag
- shift workers
- time changes
Adolescents and sleep
Circadian rhythm from people shifts from childhood to adolescence, meaning they tend to sleep later
Seasonal Affective Disorder (SAD)
Depression during periods with long dark cycles
Treatment : bright, full spectrum light
how to get back into sync?
- taking melatonin
- Reduce light (zeitgebers) when sleeping, including phone’s blue light
EGG ; Electroencephalogram
Brain waves, desynchronized and synchronized waves
Desynchronized waves
Small amplitude waves meaning lots of messages are being processed in the brain
Synchronized waves
Large amplitude waves, meaning not a lot of messages are being processed in the brain
EMG ; electromyography
Muscle tone
EOG : Electro-oculogram
Eye movements
Awake and REM sleep
- Desynchronized EGG
- Rapid eye movement
- Paralysis
- Penile erection/vaginal secretions
- Frequently associated with vivid narrative-like dreams
- PGO activity (Pons geniculate occipital)
how long is the sleep cycle?
90 minutes
which stage do we spend the most time in ?
More time it spent in Sleep Stage 4 (sleep wave ; early in the night)
while later in the night we spend the rest of majority of time in REM sleep (early morning)
Insomia
Inadequate sleep ; mainly the cause of insomnia is drug dependency ; having to take more and more medication to fall asleep
Sleep Apnea
Abstraction in the airway, gasping for air during the night
Narcolepsy
Abnormalities in the neurochemical orexin (hypocretin)
; characterized by REM Sleep
Catalepsy
Losing all muscle tone and paralyze for a couple of minutes due to a trigger (laughing, crying, exitement,etc.)
Sleep paralysis
paralyzed when they wake up or when they’re about to fall asleep may include hallucinations
in most animals, NOT HUMANS, pheromones are detected by the
vemeronasal organ
in humans , the “pheromones” we smell would be perceived through?
Olfactory receptors
Rem Sleep Disorder
Physically acting out dreams due to this disorder, when the individual is sleeping because it won’t lose muscle tone
Slow-wave sleep disorder
includes bed-wetting, night terrors, sleepwalking
Sleep beauty syndrome (Kleine-Levin) Syndrome
sleeping for hours, days, weeks, or even months; rare disorder as it affects 1 in a million due to a dysfunction of the thalamus and/or hypothalamus
- most common in teenage boys
- no treatment
why do we sleep?
- Energy conservation
- Predator avoidance
- Body Restoration
- Memory consolidation
- Removal of “garbage” and toxins
What is one of the things the brain does when asleep and, in a way, prevents Alzheimer’s disease?
The cerebral spinal fluid will clear out the brain from toxins as the brain does not have a lymphatic system to clear it out like the rest of the body ; this is called the Glymphatic system ; main thing cleared out during this process is Amyloid beta → excessive buildup causes amyloid plaque in the brain
Effects of sleep deprivation
Can affect mood, cognitive abilities, poor memory, increased impulsiveness, poor judgment
Can lead to hallucinations
Sleep longer the next night, but not catching up (more REM and stage 4 sleep)
Chronic sleep deprivation is associated with
Increased weight
Type 2 diabetes
Cardiovascular diseases
Reduced immune function
Mental health disorders often have disruptions in their sleep
REM sleep?
Probably involved memory consolidation, but not really understood
Deprived of REM, the sleep cycle will jump right into REM, so it’s shortened
Gonads
Testes / ovaries
Internal sex organs
seminal vesicles/uterus, fallopian tubes
External sex organs
Penis, scrotum/clitoris
the importance of the Y chromosome
The Y chromosome contains a gene (SRY) that causes the gonads to become testes
Mechanoreceptors
Sensitive to mechanical or physical movement
ex. free nerve ending in hair follicles
thermoreceptors
Sensitive to temperature
nociceptors
sensitive to pain
dermatoma
skin segment
how is sensory information processed?
sensory information is received from the dermatome, which travels via the spinal nerve, into the dorsal root into the spinal cord
from there it travels over the contralateral side and to the thalamus
from the thalamus, the sensory information travels to the primary somatosensory cortex on the postcentral gyrus
where is the most devotion in the cortical area?
most devotion is to the hands and face = sensitive
is the cortex plastic?
yes! It changes based on experience aka injury
how does the cortex change when an injury occurs?
When sensory input is lost, like an amputation, the area of the cortex that received sensory input from that missing limb gets taken over by adjacent inputs
Phantom limb
The sensation that an amputated limb is still present, ; often painful
Damage to the somatosensory cortical areas in the parietal cortex leads to
Astereognosia
Astereognosia
Inability to recognize objects by touch
ex. confuses wife’s head with a shirt
More damage to posterior regions in the parietal cortex where somatosensory and visual information blend it causes
Neglect syndrome
Neglect syndrome
Neglect half of their body or neglect half of their visual world
How is pain sensed?
Nociceptors releases neurotransmitter substance P, into the spinal cord
the pain message travels up to the contralateral hemisphere, ending up in both the somatosensory cortex and limbic system
Why is the limbic system aware of pain?
Limbic system is important for emotion and learning, thus pain is associated with an emotional response like sadness or anger
gate theory was coined by?
Melzack and Wall
gate theory
Believed that stimuli can shut the gate, or stop the flow of pain messages
how is analgesia produced ?
Produced by some factors that are mediated by the release of endorphins that bind into opioid receptors thus reducing pain sensitivity
analgesia
reduction of pain sensetivity
How do we test for analgesia?
Naloxone, an antagonist to endorphins (blocks opioid receptors) stops the analgesia effect = meaning that the analgesia was due to the activation of opioid receptors
How do we know analgesia did not occur?
If you inject a person with naloxone and the factor maintains its analgesic effect meaning the pain was reduced by another mechanism
what do motor neurons release?
acetycholine
Why is proprioception important
Because individuals who lose their proprioception will often not move even if their motor system is intact
what are two major proprietors
muscle spindle and golgi tendon organs
Monosynaptic stretch reflex
hammer to the knee test, stretching the muscle spindle
central pattern generators
Circuits that control coordinated movements like walking
is motor control contralateral or ipsilateral?
Contralateral
Amyotrophic Lateral Sclerosis (ALS)
Motor weakness, which progresses in losing all motor functioning, however with cognitive abilities intact
zeitebergs
Environmental cues like light and other stimuli that entertain our circadian rhythm
what is sleep?
a behaivor
what do we taste?
sweet
sour
salty
bitter
umami
how do we sense flavor?
taste and smell
papillae
Bumps in our tongue that have taste buds
Each taste buds contains how many taste receptors
50-150
taste receptors go through a cycle of growth
Once every 2 weeks
is taste information contralateral or ipsilateral?
ipsilateral
ageusia
loss of taste perception
who is a super taster?
Sensitive in taste ; taste PTC or PROP
Olfactory receptors go through a cycle of growth
once a month
Gender differences in smell?
Women are better at detecting orders; mainly during child bearing years
damage to the olfactory system leads to
ansomia
ansomia
losing sense of smell
specific anosmias
Genetic differences = not sensitive to particular smells
50% of the population has this
hyperosmia
Drug exposure or something other than damage leading to oversensitive to smells
Synesthesia
Stimulation of one sensory modality (color blue) is experience when another is simultaneously (hearing the word truck)
what is nature’s impulse?
to create a female !
Y chromosome, the SRY gene is expressed
leads to the development of testes
2 X chromosomes leads to
the development of ovaries
how is intersex occurring in humans?
Congenital adrenal hyperplasia ; adrenal glands are overgrown at birth and lead to an unusual amounts of adrenal hormones leading to sec organs to be ambiguous
the testes release 2 hormones?
- anti-mullerian hormone
- testerone
