Sensory and Motor Systems Flashcards
describe the general sensory information
- sensory receptors are specialized to transduce sensory energy into neural activity
- all sensory receptors connects to the cortex through a sequence of intervening relay neurons
- each sensory system receptors are specialized to filter a different form of energy
describe the receptive field
- all receptors has a receptive field which tells tells us the specific part of the world to which it responds
- helps us locate that sensory information
what are the 2 types of sensory receptors
- slowly adapting receptors
- rapidly adapting receptors
what is the difference between slowly adapting and rapidly adapting receptors
slowly adapting receptors - will continue to respond as long as the stimulus is present
rapidly adapting receptors - detect if something is present and are easy to activate, but response decreases if the stimulus is maintained
what is the difference between exteroceptive receptors and interoceptive receptors
exteroceptive receptors - tells us what is happening in the world around us
example: riding a bike, and noticing we are passing the trees really fast
interoceptive receptors - tells us what we are doing and what is happening internally
example: posture while moving, noticing our arms and limbs moving, within our body; internal organs
describe the term receptor density
- concentration of sensory receptors in that specific region or area of the body, that varies across the body
- how many receptors are present in that specific region
example: hand has way more receptors, making us more sensitive to what is touching it compared to our lower back which has lower receptor density and making us less sensitive to touch
what does the receptor density then does?
- these receptors then send information to the cortex through 3 or 4 intervening neurons
example: neural relays
what is a important thing to note about neural relays
it can either be amplified, modified or blocked
example: pain perception; in the moment of a sports injury, the pain is inhibited or gated, once after done playing and focusing on the location of injury, causes the pain levels to spike therefore, the neural relays are activating the localization of pain
describe the sensory messages
- can be modified at the neural relays
example: descending impulses from the cortex can block or amplify pain signals
- all signals are encoded by action potentials which travels along the peripheral nerves in the somatic nervous system until they get into the spinal cord and brain
what are the 7 visual subsystems and describe each
- suprachiasmatic nuclus - daily rhythms
- prectum - changes in pupil size in response to light
- pineal gland - long term circadian rhythms
- superior colliculus - head orienting
- accessory optic nucleus - eye movement to compensate for head movement
- visual cortex - pattern perception, depth perception, color vision
- frontal eye fields - eye movement s
what are the 5 cells that deals with sensory transmission that signals to the brain
- ganglion cells
- amacrine cell
- bipolar cells
- horizontal cells
- photoreceptors
sensory information subsystem
- within each sensory system there are many subsystems which are independent in the behaviours that are associated with that specific region
- some of these systems has a subsystem pathways that deals with the specific targeted areas within them
describe photoreceptors
- specialized receptors for light that are either sensitive to dim light (rods) or less sensitive to light and active in daylight conditions (cones)
what is the difference between rods and cones
cones - have higher distribution IN THE FOVEA region (highest visual acuity)
- daylight vision
colours: red, blue and yellow
rods - high distribution in the rest of the retina (NOT IN FOVEA)
- night vision
how does the vision work?
- light enters the eye through the cornea
- then through the lens
- is then bent towards the photoreceptors in the back of the eye
- after passing through all the nerves. The signal goes through the optic chiasm (point of crossing between hemispheres)
- right visual field goes to the LEFT hemisphere
- left visual field goes to the RIGHT hemisphere
list the 2 visual pathways
- geniculostriate pathway
- tectopulvinar pathway
what is the difference between geniculostriate pathway and the tectopulvinar pathway
geniculostriate pathway
1. pattern
2. color
3. motion recognition
- back of the cortex = central vision field
- front of the cortex = peripheral field
tectopulvinar pathway
1. detecting and
2. orienting visual stimulation
- provides information to the cortex about the absolute spatial locations of objects
what are the 3 ways to measure hearing and describe each
- frequency and pitch perception
- rate at which sound waves vibrate is measures as cycles per second (Hz) - amplitude and perception of loudness
- intensity of sound is usually measured in decibels (dB) - complexity and timbre; perception of sound quality
- pure tone of the sounds; mixture of frequencies
- sound’s complexities that determines its timbre
vision pathways between geniculostriate pathway and tectopulvinar pathway
geniculostriate
1. lateral geniculate nucleus
2. striate cortex
3. other visual cortical areas
tectopulvinar
1. superior colliculus
2. pulvinar
what is the difference between sound localization and echolocalization
sound localization
- identifying the source of air pressure waves
echolocalization
- identifying and locating objects by bouncing sound waves off them
- detecting the complexity of air pressure waves
what does the receptor cells in the inner ear detect
- detects differences in air pressure that then conveys them to the brain as action potential
what are the 3 structures of the ear and its components and describe each of the structures
- outer ear
- pinna: external part of the ear, catches air pressure waves and directs them into the ear canal
- external ear canal: amplifies the waves and directs them to the eardrum - middle ear
- ossicles: sends vibrations to the oval window - inner ear
- cochlea: contains auditory receptors which sends the action potential to the brain
where can you find high sound frequencies and low sound frequencies
high frequencies
- cochlear base
low frequencies
- apex
what happens when the wave peaks
- produces the maximal neural discharge
what role does inferior colliculus play
- role in orientation to sound location and is connected with the visual pathway
describe tonotopic representation
- spatial arrangement of where sounds of different frequencies are processed in the brain
what ventral and dorsal pathway identify
ventral pathway
- auditory
- identifies the sound
dorsal pathway
- auditory
- identifies the spatial source
example: you are crossing the street and hear a car coming, you orient your head to the sound and where it is. based on that information, you move to prevent from being hit by a car
what are the 3 groups that divides the 20 receptors in the somatosensory system (touch)
describe each
- nociception
- pain, temperature, and itch
- when damaged? nerves secrete chemicals to produce action potentials
- organs have pain receptors that causes referred pain - hapsis
- fine touch and pressure
- identifies the objects that we touch and grasp
- when touch is lost, influences our movements - proprioception
- body location + body movement = body awareness
- damage to this area, results in trouble or inability to perform daily activities
describe the term referred pain
- where the location of pain is different from the targeted region of cause
example: heart blood clots; normally this is caused by blocked arteries within the hearts itself; but location of pain is away from the heart (chest pains or numbness of the arm)
what are the 2 main somatosensory pathways
- posterior spinothalamic tract
- anterior spinathalamic tract
what is the difference between posterior and anterior spinothalamic tract
posterior spinothalamic tract
- projects to the primary somatosensory cortex AND the primary motor cortex
- apsis and proprioception
anterior spinothalamic tract
- projects ONLY to the primary somatosensory cortex
- nociception
what are the 4 subregions and describe each, that are each dominated by responses to one type of body receptor
3a - position and movement of muscles
3b - slowly and rapidly adapting skin receptors
1 - rapidly adapting skin receptors
2 - deep pressure and join sensation
true or false - the density of somatosensory receptors varies greatly from one place to another on the body surface
true
define taste
- chemicals in food that dissolves and disperses through our mouth to taste buds (taste buds = receptors)
what are the 5 types of taste and describe each
- sweet
- sensitive to calories rich foods - sour
- sensitive to acidity - salty
- related to chemicals necessary for water balance - bitter
- sensitive to some vegetables
- wide variety of toxic substances - savoury (umami)
- sensitive to protein and sessile to food addictive monosodium glutamate (MSG)
what are the 3 types of cells
- receptor hair cells
- supporting cells
- underlying layer of basal cells
what is the difference between taste and smell and describe the nerves or neurons
taste
- 3 nerves that carries information from the tongue
1. entirely to taste
2. tactile stimuli, responsible for localizing tastes on the tongue
3. related to feeding
smell
- 2 classes of neurons
1. specific odours
2. broader set of odours
define pheromones
- are biochemicals that affects the physiology or behaviour of another animal
describe the vestibular system
- contains interoceptive receptors in the inner eat
ear contains 3 semicircular canals oriented in the three places - otolith organs detects the heads position in space
(REWORD THIS to make it my own words and understanding:)
- provides the sense of balance and the information about body position that allows rapid compensatory movements in response to both self-induced and externally generated forces.
describe the motor system
- wide range of behaviours
- all aspects of the nervous system
- motor cortex
- motor information
- posterior or anterior tract
- spinal nerves
- sensory cortex
describe the 4 steps that determines how we move and describe each of them
- posterior cortex
- provides sensory information to the frontal cortex - prefrontal cortex
- plans movements - premotor cortex
- organizes movement sequences - motor cortex
- produces specific movements
what does the brainstem control and how does it relate to movement
- 26 pathways from the brainstem to the spinal cord that relays information about posture and balance
- controls movements used in
1. eating
2. drinking
3. sexual behaviours - involved with:
1. posture - ability to stand upright
2. make coordinated movements of the limbs
3. swimming and walking
4. movements in grooming
describe the basal ganglia and how it associates with behaviour
- connects the midbrain and the sensory regions with the motor cortex
- basal ganglia sends projects back to both the motor cortex and substantial nigra
- simultaneously inhibits unwanted air unnecessary movements while initiating desired movements
describe the cerebellum and how it associated with movements
- involved in acquiring and maintaining motor skills
- divided into several regions that each specialize in a different aspect of motor control
- contributes to maintaining movement accuracy and seamless motions that combines two movements
able to determine
1. the error of that action
2. where and what should have happened
3. what we can do to fix the error
list and describe the 2 spinal cord pathways
- corticobulbar tracts which goes to the brainstem
- take part in controlling facial movements - corticospinal tracts which goes to the spinal cord - takes part in controlling limb, digit. and body movements
what are the 4 spinal motor neurons and describe each of them
- motor neurons
- connect to all of the muscles
- final common path - lateral motor nuerons
- projects to muscles that control hands and fingers - intermediate motor neurons
- project to the muscles that controls the arms and soldiers - medial motor neuron
- projects to muscles that controls the trunk
vision
- light energy is converted into chemical energy in the photoreceptors of the retina
- chemical is then converted into action potentials
auditory
- air pressure waves are converted to mechanical energy
- energy activates the auditory receptors that produces action potentials
somatosensory energy
- mechanical energy activates the receptor cells
- receptors generate action potentials
taste and olfaction
- chemical molecules fit into receptors and activates action potential
- motor cortex
- brainstem
- cortical regions
- neural circuits
- motor cortex represents the way in which we make movements
- brainstem controls the whole body movements
- cortical regions are involved with movements that requires decisions or planning (skilled movement)
- neural circuits for completing these movements are represented in the spinal cord
