Physiology Exam Study guide #2 (ch 9, 10, 12)

What are sensory receptors?

Cells that receive sensory information from the environment and transduce different energy forms into graded potentials.

What type of stimuli do mechanoreceptors respond to?

Mechanical stimuli, such as touch or pressure.

What do thermoreceptors detect?

Changes in temperature, responding to cold and warmth.

What is the function of photoreceptors?

They respond to light.

Which sensory receptors respond to painful stimuli?

Nociceptors.

What is a receptor potential?

A graded potential in a sensory receptor in response to an environmental stimulus.

What happens if depolarization at the initial segment of an axon reaches threshold?

Gated ion channels open and an action potential (AP) is generated.

What is sensory adaptation?

A decrease in receptor sensitivity during maintained stimulation.

What are phasic receptors?

Receptors that respond briefly at the start of stimulation and quickly adapt.

What are tonic receptors?

Receptors that maintain a high firing rate as long as stimulation is applied.

What types of sensations are included in somatic sensation?

Touch, pressure, pain, temperature, and proprioception.

What do chemoreceptors respond to?

Chemical stimuli.

What is gustation?

The sense of taste.

What are the specialized cells in taste buds called?

Taste cells.

How does salty taste engage sensory receptors?

Na+ enters through ion channels.

How does sour taste engage sensory receptors?

H+ enters through ion channels.

What is olfaction?

The sense of smell.

What do odorants do?

Stimulate olfactory sensory neurons by binding to membrane receptors.

What are the otolith organs?

Saccule and utricle, which sense linear acceleration with respect to gravity.

How do semicircular canals detect angular acceleration?

They measure head movement in three dimensions.

What are the three components of the auditory system?

Sound waves, transduction, and perception.

What does the intensity of sound correspond to?

The amplitude of the sound wave, which determines loudness.

What does the frequency of sound correspond to?

The number of cycles per second of the sound wave, which determines pitch.

What part of the ear transmits sound vibrations to the cochlea?

The oval window.

What is the function of the organ of Corti?

Where auditory transduction occurs in the cochlea.

What are rods responsible for?

Black and white vision and vision in dim light.

What are cones responsible for?

Color vision and high-resolution vision.

What is the visual pathway responsible for?

Processing visual information in the visual cortex of the brain.

What do skeletal muscle fibers typically contain?

Myofibrils, which are packed with myofilaments.

What is the neuromuscular junction?

The point of synaptic contact between a motor neuron and muscle fibers.

What defines a motor unit?

A motor neuron and all the muscle fibers it controls.

What is muscle recruitment?

Increasing the number of motor units active to increase muscle tension.

What causes a twitch in a muscle fiber?

A single action potential (AP) leads to contraction.

What is the sliding filament mechanism?

The process where thick and thin filaments slide past each other during muscle contraction.

What happens during muscle relaxation?

Calcium moves back into the sarcoplasmic reticulum and tropomyosin covers the binding sites.

How does cardiac muscle differ from skeletal muscle?

Cardiac muscle is involuntary, has a pacemaker, and is striated due to sarcomeres.

What triggers contraction in cardiac muscle cells?

Calcium influx through voltage-gated channels.

What is smooth muscle characterized by?

It lacks striations, has small single-nucleus cells and is involuntary.

How do calcium ions affect smooth muscle contraction?

They activate cross-bridge activity by binding to calmodulin.

What are the key functions of sensory receptors?

They detect environmental changes and convert them into signals for the nervous system.

What is the role of proprioceptors?

To provide information about body position and movement.

What is the difference between general senses and special senses?

General senses (like touch) are distributed throughout the body, while special senses (like vision) are localized in specific organs.

How do olfactory receptors detect smells?

By binding to specific odorant molecules in the air.

What is the role of hair cells in the auditory system?

They transduce sound waves into electrical signals.

What structure helps to equalize pressure in the ear?

The Eustachian tube.

What is the function of the cochlea?

To convert sound vibrations into neural signals.

How does the vestibular system contribute to balance?

It detects changes in head position and motion.

What are the types of taste buds found in the tongue?

Fungiform, foliate, and circumvallate papillae.

What is the physiological role of taste?

To evaluate the quality of food and detect potential toxins.

What is the main difference between fast-twitch and slow-twitch muscle

What are sensory receptors?

Cells that receive sensory information from the environment and transduce different energy forms into graded potentials.

What type of stimuli do mechanoreceptors respond to?

Mechanical stimuli, such as touch or pressure.

What do thermoreceptors detect?

Changes in temperature, responding to cold and warmth.

What is the function of photoreceptors?

They respond to light.

Which sensory receptors respond to painful stimuli?

Nociceptors.

What is a receptor potential?

A graded potential in a sensory receptor in response to an environmental stimulus.

What happens if depolarization at the initial segment of an axon reaches threshold?

Gated ion channels open and an action potential (AP) is generated.

What is sensory adaptation?

A decrease in receptor sensitivity during maintained stimulation.

What are phasic receptors?

Receptors that respond briefly at the start of stimulation and quickly adapt.

What are tonic receptors?

Receptors that maintain a high firing rate as long as stimulation is applied.

What types of sensations are included in somatic sensation?

Touch, pressure, pain, temperature, and proprioception.

What do chemoreceptors respond to?

Chemical stimuli.

What is gustation?

The sense of taste.

What are the specialized cells in taste buds called?

Taste cells.

How does salty taste engage sensory receptors?

Na+ enters through ion channels.

How does sour taste engage sensory receptors?

H+ enters through ion channels.

What is olfaction?

The sense of smell.

What do odorants do?

Stimulate olfactory sensory neurons by binding to membrane receptors.

What are the otolith organs?

Saccule and utricle, which sense linear acceleration with respect to gravity.

How do semicircular canals detect angular acceleration?

They measure head movement in three dimensions.

What are the three components of the auditory system?

Sound waves, transduction, and perception.

What does the intensity of sound correspond to?

The amplitude of the sound wave, which determines loudness.

What does the frequency of sound correspond to?

The number of cycles per second of the sound wave, which determines pitch.

What part of the ear transmits sound vibrations to the cochlea?

The oval window.

What is the function of the organ of Corti?

Where auditory transduction occurs in the cochlea.

What are rods responsible for?

Black and white vision and vision in dim light.

What are cones responsible for?

Color vision and high-resolution vision.

What is the visual pathway responsible for?

Processing visual information in the visual cortex of the brain.

What do skeletal muscle fibers typically contain?

Myofibrils, which are packed with myofilaments.

What is the neuromuscular junction?

The point of synaptic contact between a motor neuron and muscle fibers.

What defines a motor unit?

A motor neuron and all the muscle fibers it controls.

What is muscle recruitment?

Increasing the number of motor units active to increase muscle tension.

What causes a twitch in a muscle fiber?

A single action potential (AP) leads to contraction.

What is the sliding filament mechanism?

The process where thick and thin filaments slide past each other during muscle contraction.

What happens during muscle relaxation?

Calcium moves back into the sarcoplasmic reticulum and tropomyosin covers the binding sites.

How does cardiac muscle differ from skeletal muscle?

Cardiac muscle is involuntary, has a pacemaker, and is striated due to sarcomeres.

What triggers contraction in cardiac muscle cells?

Calcium influx through voltage-gated channels.

What is smooth muscle characterized by?

It lacks striations, has small single-nucleus cells and is involuntary.

How do calcium ions affect smooth muscle contraction?

They activate cross-bridge activity by binding to calmodulin.

What are the key functions of sensory receptors?

They detect environmental changes and convert them into signals for the nervous system.

What is the role of proprioceptors?

To provide information about body position and movement.

What is the difference between general senses and special senses?

General senses (like touch) are distributed throughout the body, while special senses (like vision) are localized in specific organs.

How do olfactory receptors detect smells?

By binding to specific odorant molecules in the air.

What is the role of hair cells in the auditory system?

They transduce sound waves into electrical signals.

What structure helps to equalize pressure in the ear?

The Eustachian tube.

What is the function of the cochlea?

To convert sound vibrations into neural signals.

How does the vestibular system contribute to balance?

It detects changes in head position and motion.

What are the types of taste buds found in the tongue?

Fungiform, foliate, and circumvallate papillae.

What is the physiological role of taste?

To evaluate the quality of food and detect potential toxins.

What are the three types of muscle tissue?

Skeletal muscle, cardiac muscle, and smooth muscle.