A&P week of feburary 2 (receptors/the ear anatomy/reflex arc)

What is a reflex?

An involuntary response to a stimulus.

What are some examples of reflex actions?

Muscle contractions, heart and breathing rates, blood pressure, coughing, sneezing, vomiting.

What is the first step in a reflex arc?

A stimulus triggers a receptor.

What role does the sensory neuron play in a reflex arc?

It carries information to the spinal cord.

What is the function of interneurons in a reflex arc?

They act as a reflex center in the spinal cord, connecting sensory and motor neurons.

What is the final step of a reflex arc?

The effector, usually skeletal muscle, responds to the motor neuron signal.

What is the difference between sensation and perception?

Sensation is the sending of the signal; perception is the brain assigning meaning to that signal.

What is sensation?

Sending the signal

What is perception

The brain assigning a meaning to a signal

What are the structural classifications of receptors

Free nerve endings (dendrites), Encapsulated nerve endings, and specialized receptor cells

What are the Receptor classifications by location

Exterorecptor (Touch), Interoceptor (internal organs) and Proprioceptor (stretch receptor)

What are exteroreceptors?

Receptors that detect external stimuli such as touch, pain, and temperature.

What are interoceptors?

Detect internal body sensation. Examples: from the organs, solute levels, and blood pressure

What are proprioceptors?

Stretch receptors located in muscles and tendons that provide information about body position.

What are the functional classifications of receptors?

Chemoreceptors, Osmoreceptors, Nociceptors, Mechanoreceptors, Thermoceptors, and Photoreceptors

What do chemoreceptors detect?

Chemicals in the environment or body fluids.

What do noiciceptors detect?

pain and are often free nerve endings.

What do mechanoreceptors detect?

Physical changes in the structure, such as pressure or stretch.

What do thermoceptors detect?

Temperature

What do photo receptors detect?

Light

Where are general senses/somatosenation found?

Spread throughout the body (exteroreceptors, interioceptors, proprioceptors)

Where are special senses found?

Dedicated, specialized organs (taste, vision, hearing, etc)

What is gustation?

The sense of taste.

What are the four types of papillae involved in taste?

Taste buds, taste pores, gustatory cells, and taste hairs.

What chemical is associated with the taste of salty?

Sodium ions (Na+).

What Chemical is associated with the taste of sour?

Hydrogen (H+)

What is associated with the taste of sweet?

Glucose

What is associated with the taste of bitter?

Alkaloids

What is associated with the taste of umami

Amino Acid L-glutamate

What is the role of olfactory epithelium?

It contains bipolar neurons with cilia that detect smell.

(EXAM) Olefactory neuronrons are _____

chemoreceptors

What is the limbic system?

A part of the brain that is involved with memory, plays into nostalgic smell

What are the parts of the external ear?

Auricle, External auditory meatus (ear canal) and Tympanic Membrane

What is the tympanic membrane?

A thin membrane that separates the external ear from the middle ear and vibrates in response to sound.

What are the three ossicles in the middle ear?

Malleus, incus, and stapes.

What is the function of the ossicles?

They transfer and amplify sound vibrations.

Audition

Inner Ear: Receives vibration from the stapes

Cochlea

Snail shaped spiral structure, vibration from the stapes goes into the cochlea

Organ of Corti

Two fluid filled chambers in the cochlea, and between them is the organ of Corti

Hair Cells

In contact with the organ of Corti; send signals to the brain when vibrated

Frequency

Determines the pitch of the sound

Equilibrium

Inner Ear structures that help maintain balance

Vestibule

Part of the inner ear involved in balance

Utricle and Saccule

Structures in the vestibule that detect linear acceleration

Macula

Hair cells embedded in a protein goo in the utricle and saccule

Otoliths

Calcium carbonate crystals that give the protein goo added mass

Semicircular Canals

Three loops oriented 90 degrees from each other, detect motion in 3 dimensions

Ampulla

Structure where semicircular canals attach to the vestibule

Copula

Protein goo inside the ampulla where hair cells are embedded

Vision

Process of detecting light through the eye

Fibrous Tunic

Outer layer of the eye made up of sclera

Sclera

White part of the eye

Cornea

Clear part on the front of the eye

Vascular Tunic

Middle layer of the eye containing blood vessels

Choroid

Mostly black layer that absorbs light

Ciliary Body

Contains muscles that pull on the lens to focus

Iris

Gives color to the eye

Nervous Tunic

Innermost layer of the eye containing the retina

Retina

Detects light and contains rods and cones

Rods

Detect dim light and do not detect color

Cones

Detect color and work only in bright light

Lens

Focuses light on the retina

Anterior Cavity

Filled with aqueous humor

Posterior Cavity

Behind the lens, filled with vitreous humor

Vitreous Humor

Jelly-like substance filling the posterior cavity

What are the steps of the reflex arc?

1) Stimulus triggers receptor. 2) Sensory neuron. 3) Interneurons - reflex center 4) Motor Neuron. 5) Effector

(EXAM 1) What are photoreceptors?

specialized receptor cells

(EXAM 1) Which of the following modalities uses a mechanoreceptor to transducer the stimulus

sound