BI 201 Human Anatomy & Physiology The Senses: Classification of receptors Receptors generally...

BI 201 Human Anatomy & PhysiologyBI 201 Human Anatomy & Physiology

The Senses: Classification of receptors

Receptors generally sensitive to a specific type of stimuli

Types:

______________

______________

______________

______________

______________

Respond to physical deformation

Respond to chemicals

Respond to heat and cold

Respond to tissue damage

Respond to light


The General Senses: __________ _______________________ nerve endings:

* _____ ______ ______ include warm receptors, cold receptors and nociceptors

* ________ ________ flattened nerve endings for light touch and pressure

* _______ ________ with dendrites wrapped around base of hair follicles respond to light touch


The General Senses: Cutaneous sensation__________ nerve endings:

* _________ _________ deep pressure

* _______ _______ 2-point discrimination and light touch

* _______ _______ heavy continuous touch

* _______ ______

* _____ _______ ____

stretch of muscle

heavy/excessive tendon tension


The General Senses: PainNociceptors found in most all tissues except the brain!

_____ _____ 12-30m/sec sharp, stabbing, short duration

_____ _____ .5-2m/sec dull ache, throbbing long duration

_____ _____ arises from skin, connective tissue, muscles Superficial

Deep

_____ _____ arises from internal organs and is due to _____ (stretch), ______ ________ and _________. Causes feelings of poorly localized pain and nausea.


The Senses: PainReferred pain: interpreted as coming from a source other than actual source

Sensory neurons from viscera and skin share interneurons and brain interprets as coming from skinEx. Myocardial infarction (MI) is often felt as pain radiating down left arm. Important reference for diagnosing internal organ dysfunction.

The Senses: PainPain pathways: 1st order neurons (nociceptors)2nd order neurons (projection)3rd order neurons

Anesthesia and pain control:Local anesthesia – (ex. novacaine) decreased Na+ permeability

General anesthesia – (ex. Ether, Nitrous oxide) cross blood-brain barrier, make plasma membrane more permeable to K+

Neuromodulators – (ex. Morphine, endorphins) affect synaptic properties of pain neurons


The Special Senses: Olfaction ( )

Olfaction occurs _____ ____________________________ on patch of specialized _________.

Axons ascend through ______ ______ (in w/c bone?) to _________ _______.

Can detect ~_____ distinct smells, derived from a number of “primary odors” 7-50

1) __________ 2) __________3) __________ 4) __________5) __________ 6) __________7) __________


The Special Senses: Olfaction ( )

Olfactory neurons _____________________________________. Like taste must be ___ _____________.

Epithelium and neurons are replaced ~ ______. This is unusual for neurons.


The Special Senses: Gustation ( )Oral chemoreceptors that detect chemicals which are __ ________ (saliva) are ____ _____.

Taste buds are comprised of specialized ________ ____ that synapse with _______.

Associated mainly with ________.

Also on lips etc.


The Senses: Gustation ( )

Types of papillae:

___________

___________

___________

___________ (most numerous but NO taste buds here.

Foliate papillae


The Senses: Gustation (taste)Taste buds can detect _____ basic tastes:

________________________________________

Taste buds are “specialized” to be more sensitive to specific taste.

Taste map


The Senses: Gustation (taste)

1)

2)

3)

4)

5)


BI 201 Human Anatomy & Physiology The Senses: Classification of receptors Receptors generally...

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