BIOLOGICAL PSYCHOLOGY QUIZ 2

What are the functions of the spinal cord?

The spinal cord transmits signals between the brain and body, controls reflexes, and coordinates motor responses.

Why are root cells in the spinal cord important?

Root cells facilitate communication between sensory and motor neurons, essential for reflex actions and motor control.

How does the auditory system process sound?

Sound waves vibrate the eardrum, pass through the ossicles (malleus, incus, stapes), and ripple cochlear fluid, activating hair cells to send signals to the brain.

What is the role of the cochlea in hearing?

The cochlea converts sound vibrations into neural signals using its tonotopic organization, with high frequencies processed at the base and low frequencies at the apex.

What are basal ganglia, and what is their role in habit learning?

: Basal ganglia are brain structures involved in habit learning, showing intense activity during initial learning and minimal activity during automatic processes.

How do saliva and calories influence flavor perception?

Saliva breaks down food particles for taste receptors, while calories can impact perceived taste intensity and preference.

Why is pain considered psychologically mediated?

Pain is influenced by psychological factors like emotions and perception, beyond just physiological responses.

What are the types of pain receptors?

Pain receptors include nociceptors, A-delta fibers for sharp pain, and C-fibers for dull, aching pain

What is dysmetria, and which system does it affect?

Dysmetria is a cerebellar disorder that impairs the ability to judge distance and control movements.

What is qualitative sensory testing (QST)?

QST evaluates sensory responses to stimuli, highlighting individual variability and its implications for pain perception.

What is scanning speech?

Scanning speech, a cerebellar disorder symptom, involves slow, irregular speech with pauses between syllables.

What is the knee-jerk reflex?

A reflex where a tapped tendon sends signals to the spinal cord, causing the leg to extend automatically.

How do Golgi tendon organs protect muscles?

They detect muscle tension and trigger the autogenic inhibition reflex, causing muscle relaxation to prevent damage.

What are Meissner's corpuscles?

Skin receptors sensitive to light touch and movement, enabling texture perception.

What are Merkel cells?

Receptors providing information about sustained pressure and continuous touch.

What are receptive fields?

Specific areas in the visual field that a neuron responds to, important for detecting edges and contrasts.

How does the optic nerve transmit signals?

The optic nerve carries visual information from the retina to the brain, with fibers crossing at the optic chiasm for hemispheric integration.

What is tonotopic organization?

The arrangement in the cochlea where different sound frequencies stimulate specific locations.

What is interoception?

The "7th sense" that monitors internal states like hunger, heart rate, and breathing.

How does interoception maintain homeostasis?

It regulates vital functions like body temperature, blood pressure, and sugar levels.

What is proprioception?

The sense of body position, allowing us to coordinate movements without visual input.

Where are proprioceptors located?

Proprioceptors are in muscles, tendons, and joints, sending feedback on muscle length, tension, and joint angles.

What is cross-modal integration?

A process where one sense influences another, like sound triggering visual attention.

What causes synesthesia?

Unusual connections between sensory brain areas, leading to perceptions like seeing colors when hearing music.

What are sensory processing disorders?

Conditions causing difficulty in organizing sensory information, leading to overload and anxiety.

What are otolith organs, and what do they detect?

Located in the vestibular system, the utricle and saccule detect linear acceleration and head tilt.

What do semicircular canals detect? 

Angular acceleration, such as head rotation, using hair cells activated by fluid movement.

What is the vestibular system? 

A sensory system in the inner ear responsible for balance and spatial orientation.

How is the thalamus involved in sensory integration? 

The thalamus relays sensory input to specialized cortical areas for processing.

How do taste and smell interact? 

Smell significantly enhances taste perception; flavors are muted when smell is impaired, such as during a cold.

How do olfactory neurons detect smells? 

Odor molecules bind to receptors in the nasal cavity, triggering signals sent to the olfactory bulb and brain.

What is the role of the olfactory bulb? 

It processes signals from olfactory neurons, creating patterns of neural activity unique to each smell.

How is smell linked to emotions and memories? 

The olfactory bulb connects to the limbic system, evoking emotional and memory-related responses to odors.

hat is echolocation, and which animal uses it? 

Bats use echolocation by emitting high-frequency sounds and analyzing echoes to create a 3D map of surroundings.

What sensory system gives sharks their extraordinary hunting ability? 

Sharks use their acute sense of smell to detect tiny amounts of blood in water from miles away.

How do snakes use infrared vision? 

Infrared vision detects heat signatures, enabling snakes to hunt warm-blooded prey in darkness.

What is magnetoreception? 

The ability to sense Earth's magnetic field, used by birds for navigation during migration.

How have fish inspired underwater technology? 

Fish electrosensory systems have led to innovations in underwater exploration and communication.

How do rod cells function in vision? 

Rod cells are sensitive to low light, enabling night vision but not color detection.

How do cone cells function in vision? 

Cone cells detect color and function best in bright light, concentrated in the fovea for sharp vision.

What is the fovea's role in vision? 

It is the retinal area with a high density of cones, responsible for detailed and sharp vision.

What happens at the optic chiasm? 

Some optic nerve fibers cross to the opposite brain hemisphere, integrating visual information from both eyes.

What role does saliva play in taste? 

Saliva dissolves food particles, allowing them to interact with taste receptors on the tongue.

How do taste buds detect flavors? 

Taste buds have receptor cells that detect sweet, sour, salty, bitter, and umami flavors, transmitting signals to the brain.

How do Meissner's corpuscles and Merkel cells differ? 

Meissner's corpuscles detect light touch and movement, while Merkel cells sense sustained pressure and continuous touch.

What is alpha-gamma coactivation? 

A feedback system ensuring muscle spindles maintain the correct tension for quick responsiveness.

How do Golgi tendon organs prevent muscle damage? 

They detect tension and activate a reflex that relaxes muscles under excessive strain.

What is a receptive field in vision? 

It is the specific area of visual input a neuron responds to, crucial for detecting edges and contrasts.

What neurological condition involves unusual sensory integration? 

Synesthesia, where stimulation of one sense triggers perception in another, such as seeing colors when hearing sounds.

What are interoceptive signals? 

Signals from the body about internal states like hunger, heart rate, and breathing, influencing emotions and behavior.

What is the function of the retina? 

The retina contains photoreceptors (rods and cones) that convert light into neural signals, which are sent to the brain for visual processing.

How do rod cells contribute to vision? 

Rod cells are highly sensitive to dim light and enable vision in low-light conditions, but they do not detect color.

How do cone cells contribute to vision? 

Cone cells function in bright light and provide color vision. They are concentrated in the fovea for high visual acuity.

What is the role of the fovea in the eye? 

The fovea, located in the center of the retina, has a high density of cone cells, enabling sharp, detailed central vision.

What happens when light enters the eye? 

Light passes through the cornea, pupil, and lens before focusing on the retina, where it is converted into neural signals.

What is the function of the iris? 

The iris controls the size of the pupil, regulating how much light enters the eye.

How does the lens focus light on the retina? 

The lens changes shape (accommodation) to focus light on the retina, thickening for nearby objects and flattening for distant ones.

What happens at the optic chiasm? 

At the optic chiasm, some optic nerve fibers cross to the opposite hemisphere of the brain, integrating visual information from both eyes.

What is the relationship between photoreceptors, bipolar cells, and ganglion cells? 

Photoreceptors (rods and cones) detect light, bipolar cells transmit signals, and ganglion cells send the processed signals via the optic nerve to the brain.

What does the visual cortex do? 

The visual cortex processes and interprets signals from the retina, creating the perception of images

Auditory System

Location and Function of Hair Cells

• Respond to sound in the Organ of Corti (cochlea) • Respond to angular acceleration in the cristae ampullares (semicircular ducts) • Respond to linear acceleration (gravity) in the maculae of the saccule and utricle

• Endolymph

• Fluid surrounding hair cells

• Rich in potassium

• Crucial for maintaining ionic imbalance that triggers action potentials

• Sound Perception

• Measured in decibels (dB) and Hertz (Hz) • Human hearing range: 20 Hz to 20,000 Hz

• Auditory System

Hair Cells

Location and Function of Hair Cells

• Fundamental mechanoreceptors in

auditory and vestibular systems

• Respond to movements in the inner ear fluid

• Evolutionary Origin

• Initially evolved in fish

• Used to sense water movement

Sound Perception

Sound Detection

• Organ of Corti (cochlea) • Angular Acceleration

• Cristae ampullares (semicircular ducts) • Linear Acceleration (Gravity) • Maculae of the saccule and utricle

• Endolymph

• Rich in potassium

• Maintains ionic imbalance

• Triggers action potentials when hair cells are moved

• Sound Perception

• Decibels (dB): Logarithmic scale, each 6 dB increase doubles intensity

Basal Ganglia

Habit Learning and the Striatum

• The striatum, part of the basal ganglia, is essential for habit learning. • Striatal neurons initially fire widely across the maze during task learning. • Early Training Phase

• Striatal neurons fire at various locations, especially at choice points. • Late Training Phase

• Activity becomes restricted to the start and end points of the maze. • Example: Rats learning a T-shaped maze show this pattern.

Habit Learning

• Initial Phase of Task Learning

• Striatal neurons fire widely across the maze

• High activity at choice points

• Mastery Phase of Task Learning

• Activity becomes restricted

• Neurons fire only at start and end points

• Example observed in rats learning a

T-shaped maze

Chemical Senses: Olfaction and Gustation

• Flavor Perception

• Involves taste, smell, and tactile, thermal, and nociceptive input • Saliva acts as a solvent, transports solutes, buffers acids, and repairs the lingual epithelium

• Taste Buds

• Located on papillae on the tongue, palate, and epiglottis

• Each bud is pear-shaped with approximately 80 cells around a central taste pore

• Taste Receptor Cells

• Spindle-shaped, modified neuroepithelial cells with voltage-gated channels for Na+, K+, and Ca2+

• Microvilli project into the taste pore

• Taste Transduction

• Signal Transmission

• Olfactory System

Flavor Perception

Complex Process of

Flavor Perception

• Involves taste, smell, and tactile inputs• Includes thermal and nociceptive input from oral mucosa

Role of Saliva in Flavor Perception

• Acts as a solvent and transports solutes• Buffers acids and repairs lingual epithelium

Sensory Systems Interaction

• Several sensory systems interact to appreciate food flavors

Taste Buds and

Receptor Cells

Taste Buds Location

• Found on papillae on the tongue, palate, and epiglottis

• Each bud is pear-shaped

• Contains approximately 80 cells around a central taste pore

• Taste Receptor Cells

• Spindle-shaped, modified neuroepithelial cells

• Have voltage-gated channels for Na+, K+, and Ca2+

• Microvilli project into the taste pore

• Replaced every 9-10 days

Taste Transduction

Salts

• Na+ ions diffuse through channels

• Causes depolarization

• Acids (Sour) • H+ protons influx through Na+ channels

• Via proton transport membrane protein

• Causes depolarization

• Some acids block K+ efflux

• Sweet • Sweet solutes bind to membrane receptors

• Bitter • Umami

Olfactory System

• Sensitivity of Olfactory System

• Distinguishes between 1,000 to 4,000 odors

• Odors classified into floral, fruit, spicy, resin, burnt, and putrid

• Transduction Process

• Odorant molecules bind to membrane receptors

• Activates adenylyl cyclase and causes depolarization

• Olfactory Bulb Function

• Neurons converge onto glomeruli • Synapse with mitral and tufted cells

• Lateral inhibition via periglomerular cells

• Neural Coding

• Second Order Sensory Neurons

NeuronsDisorders of the Motor System

• Spasticity

• Velocity-dependent resistance to passive limb movement • Characterized by a 'spastic catch' and 'clasp-knife reflex' • Involves altered firing of gamma motor neurons and increased alpha motor neuron activity

• Basal Ganglia Disorders

• Dyskinesias: Abnormal, involuntary movements

• Examples: resting tremors in Parkinson's, athetosis, chorea in Huntington's, ballismus, tardive dyskinesia

• Akinesias: Abnormal, involuntary postures or lack of movement • Examples: rigidity, dystonia, bradykinesia

• Cerebellar Disorders

• Dysmetria: inappropriate force and distance with movements

• Dysdiadochokinesia: Inability to perform rapidly alternating movements

movementsMotor Units and Muscle Receptors

• Alpha Motor Neurons

• Lower motor neurons that innervate skeletal muscle

• Release acetylcholine at the neuromuscular junction

• Initiate muscle contractions

• Rate Code

• Muscle force controlled by motor neuron firing rate

• Higher firing rates lead to greater force generation

• Summation of twitches can lead to tetanus

• Gamma Motor Neurons

• Innervate intrafusal fibers within muscle spindles

• Do not provide force

• Maintain spindle sensitivity to stretch

Ocular Motor

Control

• Purpose of Ocular Motor Systems

• Control eye position and movement • Focus images onto the retinas

• Coordinate eye movement for aligned binocular fields

• Extraocular Muscles

• Medial/Lateral Rectus: Horizontal movement • Superior/Inferior Rectus: Vertical movement and minor rotations

• Superior/Inferior Oblique: Vertical movement and minor rotations

• Muscle Synergies

• Types of Eye Movements

• Vestibulo-ocular Reflex

• Nerve Damage

Purpose and

Extraocular

Muscles

• Purpose of Ocular Motor Systems

• Control eye position and movement • Focus images onto the retinas

• Accommodation for focusing objects on the foveae

• Coordinate eye movement for aligned binocular fields

• Extraocular Muscles

• Medial/Lateral Rectus: horizontal movement • Superior/Inferior Rectus: vertical movement and minor rotations

• Superior/Inferior Oblique: vertical movement and minor rotations

• Muscle Synergies

• Upward movement: superior rectus and inferior oblique contract, inferior rectus and superior oblique relax

• Downward movement: inferior rectus and superior oblique contract, superior rectus and inferior oblique relax

Types of Eye

Movements

Vestibulo-ocular • Compensates for head movements

• Initiated by vestibular mechanisms

• Optokinetic

• Initiated by visual mechanisms

• Occurs during slow head movements

• Vestigial in humans

• Vergence

• Adjusts for different viewing distances

• Smooth Pursuit • Follows a moving visual target • Saccade

Visual Processing:

Cortical Pathways

• Visual Field Defects

• Areas of vision loss

• Detected through perimetry testing

• Determines ability to detect small

objects

• Identifies presence of deficits in visual field

Visual

Processing:

Eye and

Retina

• Visual Perception

• Processes form, visual acuity, visual field representation, binocular fusion, and depth perception

• Central vs. Peripheral Vision

• Visual Field

• Monocular and Binocular Fields

• Visual Acuity

• Color Vision

• Binocular Fusion

• Lens Accommodation

• Myopia

• Diabetic Retinopathy

• Retina

Visual

Perception

and Central

vs. Peripheral

Vision

• Visual Perception

• Processes form

• Handles visual acuity

• Represents visual field

• Manages binocular fusion

• Enables depth perception

• Central Vision

• Color-sensitive

• High acuity

• Operates at high light levels

• Peripheral Vision

• More sensitive at low light levels

Visual Field

and Acuity

• Visual Field

• Area of space perceived when eyes are fixed

• Described as a hemisphere

• Obscured by brow, nose, and cheekbones

• Monocular Visual Field

• Visual field of one eye

• Binocular Field

• Area of overlap between fields of both eyes

• Visual Acuity

• Ability to detect and recognize small objects

Color Vision

and

Binocular

Fusion

• Color Vision

• Ability to detect differences in wavelengths of light • Trichromatic vision includes red, green, and blue

• Red-green color blindness results from missing red or green photopigments

• Binocular Fusion

• Combines images from both eyes into a single perception

• Allows depth perception

• Strabismus can cause loss of binocular fusion

• Amblyopia may result from long-term strabismus, leading to functional blindness in one eye

Lens Accommodation

and Myopia

• Lens Accommodation

• Eye's ability to adjust refractive properties

• Focuses on both near and far objects

• Lens curvature increases during accommodation

• Increases refractive power of the eye

• Focuses image on the retina

• Myopia (Near-sightedness) • Eye cannot focus on objects more than 30 ft. away

• Corrected with concave lenses

Diabetic Retinopathy

and Retina

• Diabetic Retinopathy

• Damage to receptor cells and retinal neurons

• Caused by swollen blood vessels and/or bleeding in the choroid

• Can result in blindness

• Retina Function

• Image projected onto photoreceptor cells on the retina's inner surface

• Signals sent to bipolar cells and then retinal ganglion cells

• Retina output is independent, parallel information streams regarding visual stimuli

Ocular Motor

System

• Function of Ocular Motor System

• Controls eyelid closure

• Regulates light entry into the eye

• Manages eye's refractive properties

• Controls eye movements

• Muscles Involved

• Ocular reflexes and voluntary motor responses

• Intraocular and extraocular muscles

• Muscles of the eyelid

• Iris Control • Iris Sphincter: Parasympathetic system (decreases pupil size) • Cranial Nerves

Cranial

Nerves

• Oculomotor Nerve (III) • Controls a subset of extraocular muscles

• Trochlear Nerve (IV) • Controls a subset of extraocular muscles

• Abducens Nerve (VI) • Controls a subset of extraocular muscles

• Trigeminal Nerve (V) • Innervates first somatosensory afferents for the face

• Facial Nerve (VII) • Motor neurons to facial muscles

• Gustatory afferents to anterior tongue

• Parasympathetic fibers to lachrymal and salivary glands

Pain

Modulation

and

Mechanisms

• Pain Perception

• Interpreted in the brain

• Modulated by drugs like analgesics and anesthetics

• Endogenous Opioids

• Body's own pain-relieving system

• Involves opioid receptors (mu, delta, kappa) and peptides (beta-endorphins, enkephalins, dynorphins) • Modulate nociceptive input by inhibiting neurotransmitter release or opening potassium channels

• Opioid Release

• Released in response to stress

• Inhibit pain by activating the midbrain descending system

• Stress-Induced Analgesia (SIA) • Both opiate and non-opiate forms exist

Pain

Principles

• Pain Intensity Measurement • Measured by Just Noticeable Differences (JND) • Approximately 22 JNDs for heat-induced pain

• Nociceptors

• Increase discharge frequency with increased stimulus intensity

• Encode stimulus intensity and location

• Types of Pain

• Pricking Pain: Sharp, localized, short-duration pain carried by A-delta fibers

• Burning/Soreness Pain: Diffuse, slow onset, longer duration pain carried by C fibers

• Aching Pain: Sore, diffuse pain from viscera and deep structures, carried by C fibers

• A Delta Fibers

• Pain Receptors

Pain Tracts

and Sources

• Fibromyalgia

• Characterized by widespread chronic pain

• Includes fatigue, anxiety, and depression

• Has a genetic component • Headaches

• Poorly understood type of pain

• Numerous potential causes

• Causes include structural, infectious, vascular, metabolic, toxic, trauma related, and others

• Visceral Pain

• Carried by paleospinothalamic, sympathetic nerves, and archispinothalamic tracts

• Transmitted to the CNS

Somatosensory

Processes

• Receptive Fields

• Each somatosensory neuron responds to specific stimuli within a specific body region

• Size of receptive field is related to the body area it represents

• Smaller receptive fields for fine motor control • Smallest receptive fields: finger pads, lips, and tongue

• Largest receptive fields: shoulders, back, and legs

• Spinothalamic Pathways

• Pain sensations with a segmental pattern

Somatosensory

Systems

• Modality Specificity

• Neurons respond to specific somatic sensations

• Discriminative touch includes touch, pressure, flutter, and vibration

• Tactile Stimuli • Touch senses minimal force

• Pressure senses greater force

• Object movement or flutter (20-50 Hz) and vibration (100-300 Hz) • Somatosensory Receptors

• Most receptors are formed from 1° afferent axon endings

• Merkel cells are an exception

• Adaptation of Afferents

• Cutaneous Receptors

Functions of the Somatosensory System

Provides accurate information about touch

• Involves proprioception for body position awareness

• Includes nociception for pain detection

Vestibular

System

• Membranous Labyrinth Components

• Semicircular ducts: Detect angular acceleration

• Otolith organs: Saccule and utricle detect linear acceleration

• Cochlea: Part of the auditory system

• Semicircular Ducts Function

• Respond to angular acceleration

• Contain ampulla with crista and hair cells

• Work in pairs to detect head movements

• Kinocilia Orientation

• Oriented ampullofugally in semicircular canals

• Otolith Organs Function

• Caloric Response