Nervous system- the five senses

All sensory organs contain..?

Sensory receptors-dendrites that react to a certain external or internal stimulus

What are the five major types of sensory receptors?

1.Mechanoreceptors (touch)

2. Thermoreceptors (temp variations)

3. Pain receptors (non receptors)

4. Chemoreceptors (chemicals)

5.photoreceptors (light)

Each sensory organ has..?

One or more of these receptors

The impulses produced in the skin are called?

cutaneous sensations

Cutaneous sensations include what five things?

Touch, heat, cold pressure and pain

These receptors are not equally _______ throughout the body.

Distributed

Some body parts are more _______ than others.

Sensitive

What are free nerve endings?

Sense pain, temp, touch and pressure

What is Meissner's corpuscles?

Encapsulated nerves endings found in hairless skin that detect light touch

What are Markel's disk?

Detect light touch and pressure within epidermis

What are hair follicle receptors?

The tech movement of hair

What are Ruffini's corpuscles?

Detect depress and stretching of the skin

What are Pacinian corpuscle?

Encapsulated nerve endings that detect depress and vibrations

The remaining senses- site hearing smell and taste are..?

Special senses

Why are they special senses?

Because the receptors are clustered and specialized organs example or in a small area area

What is an additional special sense that has receptors housed in the ear?

Balance

Balance is an additional special sense that has receptors house in?

The ear

The highest is covered with an..?

Eyelid

And I meet the corners of the eye at the..?

Medial commissure and the lateral commissure

Eyelid is lined with

Eyelashes

A thin membrane called the..?

Conjunctiva covers the surface of the eyeball and the inner layer of the eyelid

The Conjunctiva covers what of the eyeball?

The surface of the eyeball and the inner layer of the eyelid

The Conjunctiva secrete mucus to..?

Lubricate the eyeball

The lacrimal apparatus is a..?

A group of structures that also lubricate the eye

Lacrimal glands above the eyes constantly release tears to..?

To cleanse and moisten the eye

Tears contain what three things

Mucus, antibodies, and lysozyme (an anti-bacterial enzyme)

The tears drain into ducks called the?

Lacrimal canaliculi

Where do tears go after they drain into the lacrimal canaliculi?

The lacrimal sac

Where to tears go after they drain into the lacrimal sac?

Into the nasal cavity through the nasolaceimal duct

What are the three tissue layers of the eye?

sclera, choroid, retina

What is sclera?

White of the eye; made of fibrous connective tissue protects and shapes the eye

What is choroid ?

Pigmented, vascular membrane that includes the iris and pupil

What is Retina?

Contains photo receptors that turn light energy into nerve impulses

What is made of thick transparent tissue that allows light into the eye?

The cornea

The cornea is made out of what?

Of thick, transparent tissue

The cornea allows what into the eye?

Light

What is the colored part of the eye that is located behind the cornea?

The iris

The iris is..?

The color part of the eye that is located behind the cornea

The iris works with the?

Pupil to regulate light entering the eye

What works with the pupil to regulate light entering the eye?

Iris

What works with the Iris to regulate light and turn the eye?

The pupil

The pupil is the..?

Opening in the center of the iris through which light enters

What does light and through?

The pupil

Low light makes your pupil be what?

Wide open

Highlight makes your pupil be what?

Nearly closed

what is a semi solid disc that detect light waves towards the retina?

The lens

The lens is a semi solid disk that enters light waves towards the?

Retina

The lens is controlled by what two things?

It is controlled by capillary muscles and suspensory ligaments

The capillary muscle and the suspensory ligaments help to do what to the lens?

Help bend or flatten the land based on the distance of the image being viewed

What is in front of the lens that is a fluid?

Aqueous humor

The Aqueous humor does what to the cornea?

Nourishes the cornea

What is behind the lens?

The vitreous humor

What is a thick jelly like fluid that refracts light and fill the spaces between the lens and the retina?

Vitreous humor

The retina contains thousands of what?

Photo receptors

What are two kinds of photo receptors??

Rods and cones

The photo receptors of rods do what?

Distributed all over the retina, responsible for vision and low light extremely sensitive

The photo receptors of cones do what?

Concentrated in center of retina, responsible for protection of color, less sensitive

How does the eye perceive images?

In order to see an image at light passes through the eye, and hit the retinal pigment epithelium(RPE) on the back of the eye

Like causes what type of changes that begin an impulse?

Causes molecular changes that begin an impulse

The light causes molecular changes that begin what?

Impulse

The impulse travels through two things first?

Rods and cones

After impulses travel through the rods and cones, it goes where?

Bipolar neurons

Where is the third place that impulses travel through?

Ganglion cells

After impulses travel through the ganglion cells where do they travel to?

travel to the brain

How do impulses travel through the brain what is used?

Impulses travel to the brain via the optic nerve

What is a tiny pit that contains only cones?

Fovea central is

The fovea centralis are what?

The point that provides the sharpest image

What isn’t there of ,where the optic nerve meets the eye?

No photo receptors

Where is there? No photo receptors

No receptors or the optic nerve meets the eye

The place that has no photo receptors where the optic nerve meets the eye is called what?

Called a Blindspot

Because the Blindspot affects different parts of each eye, it is not regularly noticed so the brain does what?

The brain ”fills in” the missing images

How can the shape of the eye effect vision?

in some people that I is too long or too short causing nearsightedness or far-sightedness

What is another name for near-sightedness?

Myopia

What is another name for far-sightedness?

Hyperopia

What helps with vision problems caused by the eye being too long or too short?

Corrective lenses

How do corrective lenses help with vision problems?

Hope to refract the lights, so it accurately coverages on the retina

The structures of the ear all work together to do what?

To collect and transfer sound vibrations to the auditory nerve

What does the ear use to transfer sound vibrations to the auditory nerve?

Mechanoreceptors

How are soundwaves collected?

Sound waves are collected by the auricle (outer ear)

After sound waves are collected by the outer ear they are passed through what?

Our past through the external auditory canal

What does the sound waves vibrate?

The tympanic membrane( eardrum)

After sound waves vibrates the tympanic panic membrane the sound wave travels through what section of the ear?

sound waves travel through the middle ear

The middle ear is a set of what three tiny things?

Three tiny jointed bones (Ossicles)

What are the three tiny jointed bones of the middle ear?

Malleus, incus, and stapes

The malleus, incus, and stapes are more commonly known as what other three names?

Hammer, the anvil, and the stirrup

What do the hammer the anvil and the stirrup do?

They amplify the sound waves to the inner ear(the back/last part of the ear)

The three bones of the middle ear amplify the sound through a membrane called the?

Oval window

What does the inner ear contain that is like a bony snail shaped structure?

Cochlea

The cochlea (snail shaped structure) contains a membrane filled with what?

Filled with fluid (perilymph)

What is the name of the tiny portion of the cochlea that creates an impulse?

Impulse is called the organ of corti

The sound of the ossicle vibrates what?

Perilymph

The perilymph vibrates what?

basilar membrane

basilar membrane Has water attached to it?

Has tiny receptor cells attached to it

What things from the cell receptors move against the tectorial membrane?

Hairs(stereocillia)

The Harris of the receptor cells move against what?

Tectorial membrane

When the hairs of the receptor cells move against the factorial membrane what happens?

depolarizing the end of the nerve cells and beginning an action potential

The action potential is transferred through?

Transferred through the auditory nerve

When the action potential is transferred through the auditory nerve what does it do to the brain?

the brain registers these impulses as sounds

What is vestibular apparatus?

A fluid filled maze of chambers and canals within the inner ear

What do semi circular canals do?

Help with balance when we are moving(dynamic equilibrium)