Chapter 44 - Sensory Systems Flashcards
Provide information from our environments that is crucial for survival
Sensory receptors
Sene external stimuli
Exteroceptors
Sense internal stimuli
Interoceptors
Three groups of receptors
- Mechanoreceptors
- Chemoreceptors
- Energy-detecting receptors
Are stimulated by mechanical forces such as pressure
Mechanoreceptors
Detect chemicals or chemical changes
Chemoreceptors
React to electromagnetic and thermal energy
Energy-detecting receptors
Sensory information is perceived in a four step process
- Stimulation
- Transduction
- Transmission
- Interpreting
Receptor potential in sensory cell created
Transduction
Action potential in sensory neuron
Transmission
CNS processing
Interpretation
Sensory cells respond to stimuli via ___________ in their membranes
Stimulus-gated Ion Channels
Stimulus-gated ion channels are open or close depending on the ____________
sensory system involved
Depolarization of receptor cell occurs
Receptor potential
What will respond to a specific kind of stimulus
Receptor Potential
Six different kinds of Mechanoreceptors
- Nociceptors
- Thermoreceptors
- Detect touch
- Proprioceptors
- Baroreceptors
- Hair Cells
- Transmits impulses based on cell damage
- Perceived as pain
- Most consist of free nerve endings located throughout the body (especially where damage is most likely to occur)
Nociceptors
- Naked dendritic endings of sensory neurons
- Sensitive to changes in temperature
- Contain ion channels that are receptive to hot and cold
Thermoreceptors
________ located higher in the skin, and are much more numerous, than _____
- Cold receptors
2. Warm receptors
Contain sensory cells with ion channels that open in response to membrane distortions
Types detected by touch
- Monitor muscle length and tension
- Provide information about the relative position or movement of animal’s body parts
Proprioceptors
Where are proprioceptors?
- Muscle spindles
- Golgi tendon organs
- Monitor blood pressure
- Detect tension or stretch in the walls of those blood vessels (When blood pressure decreases, the frequency of impulses decreases)
Baroreceptors
In baroreceptors, branched network of afferent neurons are in the _____ or_______
- Carotid sinus
2. Aortic arch
- When stereocillia bend they send an action potential to a sensory neuron
Hair Cells
Speciaized cells with cytoplasmic extensions called ______
Stereocillia
Three senses in hair cells
- Water current
- Hearing
- Balance
Consists of canals running the length of the firsh’s body beneath the skin surface
Lateral Line
The lateral line contains _______ in a gelatinous _______
- Hair cells
2. Cupula
How does the lateral line system work?
- Innervated by sensory neurons that transmit impulses
2. Bending of sterecilia detects currents
The detection of vibrations
Hearing
The process of detection of vibrations
- Perceived as sound
2. Involves the bending of stereocillia in hair cells
Two advantages the involve with the bending of stereocillia in hair cells
- Auditory stimuli travel farther and more quickly than chemical ones
- Auditory receptors provide better directional information than chemoreceptors
- Inner ear
- Has three chambers filled with fluid
- Wrapped in a coil
- Vibration travel down these canals
Cochlea
The cochlea contains what organ?
Organ of Corti
How does the organ of corti work?
- Has a basilar membrane with hair cells
- Vibrations of the basilar membrane’s hair cells press the stereocilia against the tectorial membrane
- Send nerve impulses to brain, where they are interpreted as sound
Key words with the cochlea
- Organ of Corti
- Basilar membrane
- Tectorial membrane
Mammals that have the ability to perceive presence and distance of objects by sound
Echolocation
Who uses echolocation?
- Bats
- Shrews
- Whales
- Dolphins
How does echolocation work?
Animals emit sounds and then determine the time it takes these sounds to return
How does balance work in vertebrates and what are the parts used?
In vertebrates, the gravity receptors consist of two chambers in the membranous labyrinth
What are in the utricle and saccule?
Hair Cells
Hair cells are embedded in a calcium rich _______
Otolith membrane
_______ causes the ________ to move and ______ to bend
- Head movement
- Otolithic membrane
- Stereocilia
Detect angular acceleration in any direction
Semicircular canals
Semicircular canals have swollen chambers called ____
Ampullae
In semicircular canals have hair cell stereocilia. Within a gelatinous _____ protrude into them.
Cupula
What does acceleration do?
- Moves fluid in the canals
- Bends the cupulla
- Bends the stereocilia
- Can bind to particular chemicals in extracellular fluid
- Membrane of sensory neuron becomes depolarized and produces action potentials
- Senses
Chemoreceptors
Three senses from chemoreceptors
- Taste
- Blood
- Blood composition
Two parts of gustation
- Taste
2. Taste buds
Taste is broken down into what five receptor types?
- Sweet
- Sour
- Salty
- Bitter
- Umami
Collection of chemosensitive cells associated with afferent neurons
Taste buds
Where do arthropods have taste chemoreceptors?
Flies have them in sensory hairs located on their feet
Involves neurons located in the upper portion of the nasal passages
Smell
Olfaction transmits impulses directly to the brain via _____
The olfactory nerve
Humans have over ____ receptors and can discern thousands of different smells
50
- Found in the aortic and carotid bodies
- Sensitivity primarily to the pH of plasma
Peripheral chemoreceptors
- Found in the medulla oblongata of the brain
- Sensitive to the pH of cerebrospinal fluid
Central chemoreceptors
Vision begins with the capture of light energy by ______
Photoreceptors
Many invertebrates have photoreceptors clustered in an ________
Eyespot
______ can perceive the direction of light but cannot construct a visual image
Flatworms
Four different phyla have evolved well-developed, image forming eyes
- Annelids
- Mollusks
- Arthropods
- Chordates
Vision in different phyla is similar in structure but evolved independently. This is an example of _______
Convergent evolution
Two components in the vertebrate retina
- Rods
2. Cones
Black and white vision when illumination is dim
Rods
- Color vision and high visual acuity (sharpness)
- Most are located in the central region of the retina
Cones
- In rods
- Broad ranging pigment that detects values
Rhodopsin
Cones have _____
Photopsins
Each rhodopsin and photopsin has a different ________
Amino acid sequence
What do the amino acid sequences do in the rhodopsin and photopsins?
- Can each register a different range of the EMS
2. The more you have the more color you see
Carnivores have two types of cones called _____
Dichromats
Humans have three kinds of cones called ______
Trichomats
Color blind humans are usually _____
Dichromats
Birds have four cones called _____
Tetrachromats
Birds are special because they can see what humans see and _____
Ultraviolet
_____ is a transparent structure that completes focusing light on the _______
- Lens
2. Retina
People who are nearsighted or farsighted do not properly focus the image on the _____
Retina
The retina consists of three layers of cells
- Photoreceptors
- Bipolar layer
- Ganglion cells
External layer of retina contains
Photoreceptors
Middle layer of retina contains
Bipolar layers
Layer closest to the eye cavity in the retina contains
Ganglion cells
________ stimulate ______ which stimulate _____ in the eye
- Photoreceptors
- Bipolar cells
- Ganglion cells
Transmit impulses to the brain via optic nerve
Ganglion cells
First three steps in visual processing
- Action potentials in the optic nerves are relayed from the retina to the thalamus
- They are then projected to the occipital lobes of the cerebral cortex
- Each hemisphere of the cerebrum receives input from both eyes
Vision that give the ability to perceive 3-D images and depth
- Two fields of vision overlap
Binocular vision
Primates and predators have two eyes, one located on each side of the face called what kind of vision?
Binocular Vision
Prey animals generally have eyes located where?
On the sides of their head
Eyes on the sides of an animals head produces two things
- Reduces binocular vision
2. Enlarges the overall field
The only vertebrates that can sense infrared radiation are ___
Snakes
Snakes have a pair of ____ on either side of their head
Pit organs
These locate heat sources in the environment, including prey in darkness
Pit organs
The elasmobrachs (sharks, rays, and skates) have ______
Electroreceptors
Can sense electrical currents generated by the muscle contraction of their prey
Ampullae of Lorenzini
- Eels, sharks, bees and many birds
- Navigate along the magnetic field lines of the Earth
Magnetoception