what types of sensory receptors are there? nervous system (senses) somatic visceral general special...

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What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated Unencapsulated Mechanoreceptors Chemoreceptors Thermoreceptors Nociceptors Photoreceptors

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Page 1: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

What types of sensory receptors are there?

Nervous System (Senses)

Somatic

Visceral

General

Special

Exteroreceptors

Enteroreceptors

Proprioceptors

Encapsulated

Unencapsulated

Mechanoreceptors

Chemoreceptors

Thermoreceptors

Nociceptors

Photoreceptors

Page 2: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

What are the types of cutaneous sense organs?

Nervous System (Senses)

Page 3: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

What is the network-like pattern on fish and tadpoles?

Nervous System (Senses)

Neuromasts have sensitive hair cells with kinocilia extending into a cavity, fluid or a cupula

Organized into mechano- or electroreceptive structures

Pattern refered to as a lateral line (canal) or cephalic canal

Page 4: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: Balance

Kinetic labyrinth

Responds to movement of endolymph (fluid) in semicircular canals i.e. angular (rotational) acceleration

Nervous System (Senses)

Page 5: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: Balance

Static labyrinth

Responds to force of gravity and linear acceleration

Nervous System (Senses)

Page 6: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: HearingAuricle collects sound waves

External auditory meatus (canal) channels sound waves

Tympanic mem. & ossicles conduct sound waves

Nervous System (Senses)

Page 7: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: Hearing

The oval window transfers sound waves to the liquid inside the cochlea

Three scala:vestibulimedia (cochlear duct)tympani

Nervous System (Senses)

Page 8: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: HearingSound waves vibrate basilar membrane causing microvilli to bend

Bending causes depolarization in hair cells that in turn create action potentials in synapsing neurons

Nervous System (Senses)

Page 9: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: HearingBasilar membrane stiff near vestibule, responds to higher frequency sounds (20,000 Hz).

Lower pitches picked up further in to cochlear duct, with lowest frequencies (200 Hz) at apex

Excess wave energy travels back down via scala tympani and out round window

Nervous System (Senses)

Page 10: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Special Senses: Olfaction (smell)Nervous System (Senses)

Page 11: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Special Senses: Gustation (taste)

Chemoreceptors that detect chemicals which are in solution (saliva) are taste buds.

Taste buds are comprised of specialized epithelial cells that synapse with neurons.

Associated mainly with papillae.

Also on lips etc.

Nervous System (Senses)

Page 12: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: Gustation (taste)

Types of papillae:

Circumvallate

Foliate

Fungiform

Filiform (most numerous but NO taste buds here. Foliate papillae

Nervous System (Senses)

Page 13: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: Gustation (taste)

Salty

Nervous System (Senses)

Page 14: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

What are the layers of the eye and what are their functions?3 distinct layers of tissue in eye:

FibrousSclera & cornea

VascularChoroid, iris etc.

NervousRetina

Clear light pathway

Nervous System (Senses)

Page 15: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

What is the external anatomy of the eye?Nervous System (Senses)

Page 16: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

What is the internal anatomy of the eye?Nervous System (Senses)

Page 17: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

How do our eyes control the amount of light entering?

Cornea refracts light as it head towards lens

Iris is attached to ciliary body and consists of contractile tissue (smooth muscle). Coloration is due to varying amounts of melanin

Pupil is simply the hole in the center of the iris

Nervous System (Senses)

Page 18: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

How do we focus the image?

Ciliary body contains smooth muscle fibers, which allow the distortion of the lens via suspensory ligaments.

Ciliary processes are very vascular and produce aqueous humor (watery fluid in anterior compartment).

Nervous System (Senses)

Page 19: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

How is light converted into action potentials?

3 neuronal layers of the retina:

Photoreceptors

Also bipolar neurons and Ganglionic neurons

Nervous System (Senses)

Page 20: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

Are all photoreceptors created equally?Rods (~120 million each)

Cones (~6-7 million each)

Nervous System (Senses)

Page 21: What types of sensory receptors are there? Nervous System (Senses) Somatic Visceral General Special Exteroreceptors Enteroreceptors Proprioceptors Encapsulated

The Senses: Vision

Photoreceptors are rather unique in that they are hyperpolarized as a result of stimulation.

In dark (no stimulus) leaky Na+ channels.

In light (stimulus) Na+ channels close and hyperpolarization occurs

How is light converted into action potentials?Nervous System (Senses)