CHAPTER 19 GENERAL AND SPECIAL SENSES

STIMULI

OUR BODIES ARE CONSTANTLY EXPOSED TO SENSORY INFORMATION CALLED

OUR CONSICOUS AWARENESS TO THESE STIMULI IS CALLED

SENSATION

STIMULI ARE DETECTED BY

SENSORY RECEPTORS IN THE BODY

THERE ARE RECEPTORS FOR

GENERAL SENSES - TEMP, PAIN, TOUCH, STRETCH, AND PRESSURE

SPECIAL SENSES - GUSTATION, OLFACTION, VISION, EQUILIBRIUM AND HEARING

RECEPTORS ACT AS

TRANSDUCERS - THEY CHANGE ONE FORM OF ENERGY INTO ANOTHER

RECEPTORS HAVE

RECEPTIVE FEILDS - AREAS THROUGH WHICH THEIR SENSITIVE ENDS ARE DISTRIBUTED

GENERAL SENSE RECEPTOS ARE DISTRIBUTED THROUGHOUT THE

SKIN AND ORGANS

SPECIAL SENSE RECEPTORS ARE HOUSED IN

COMPLEX ORGANS IN THE HEAS that are specialized for specific sensory modalities.

THREE CRITERIA ARE USED TO DESCRIBE RECEPTORS

• RECEPTOR DISTRIBUTION

• STIMULUS ORIGIN

  • MODALITY OF STIMULUS

SENSORY RECEPTORS DISTRIBUTION

• SOMATIC RECEPTORS

• VISCERAL RECEPTORS

  • SPECIAL SENSE RECEPTORS

SOMATIC RECEPTORS

MONITOR A VARIETY OF STIMULI INCLUDING TEXTURE, PRESSURE, TEMPERATURE, PAIN, VIBRATIONS, AND STRETCH

FOUND IN

• SKIN

• MUSCOUS MEMBRANES LINING BODY CAVITIES

• JOINTS

• MUSCLES

• TENDONS

VISCERAL RECEPTORS

DETECTS STRETCH, CHANGES IN CHEMICAL CONCENTRATIONS, TEMPERATURE AND PAIN

FOUND IN - WALLS OF INTERNAL ORGANS AND BLOOD VESSELS

SPECIAL SENSE RECEPTORS

ARE SPECIALIZED, COMPLEX SENSE ORGANS LOCATED IN THE HEAD

SPECIAL SENSES ARE SMELL, TASTE, VISION, HEARING, AND EQUILIBRIUM

EXTROCEPTERS

DETECT STIMULI FROM EXTERNAL ENVIORMENT

INCLUDES RECEPTORS IN SKIN, IN BODY CAVITY LINING AND IN SPECIAL SENSE ORGANS

INTROCEPTORS

DETECH STIMILI IN INTERNAL ORGANS

INCLUDES STRETCH RECEPTORS IN SMOOTH MUSCLE AS WELL AS RECEPTORS FOR PAIN, PRESSURE, TEMP, AND CHEMICAL CHANGES IN VISCERA

PROPRIOCEPTORS

DETECT STIMULI PERTAINING TO BODY POSITION

FOUND IN MUSCLES AND TENDONS AND JOINTS

CLASSIFICATION BY MODALITY DEPENDS ON THE

STIMULATION AGENT

CHEMRECEPTORS

DETECT SPECIFIC MOLECULES DISSOLVED IN FLUID

THERMORECEPTORS

DETECTS CHANGES IN TEMPERATURE

PHOTORECEPTORS

DETECT CHANGES IN INTENSITY, COLOR, AND POSITION OF LIGHT

MECHANORECEPTORS

DETECT TOUCH, PRESSURE, VIBRATION, AND STRETCH

NOCICEPTORS

DETECT PAINFUL STIMULI

EAR CONTAINS THE ORGANS OF

EQUILIBRIUM AND HEARING

EAR IS DIVIDED IN TO THREE DISTINCT ANATOMIC REGIONS

EXTERNAL, MIDDLE, INNER

MIDDLE EAR CONTAINS AIR FILLED

TYMPANIC CAVITY, JUST MEDIAL TO TYMPANIC MEMBBRANE

AUDITORY TUBES THAT CONNECTS

MIDDLE EAR TO NASOPHARYNX

THREE AUDITORY OSSICLES ( SMALL BONES )

TRANSMIT SOUND WAVES TO INNER EAR

• MALLEUS

• INCUS

  • STAPES

MALLEUS

BETWEEN TYMPANIC MEMBRANE AND INCUS

INCUS

IS THE MIDDLE OSSICLE

STAPES

BETWEEN INCUS AND OVAL WINDOW TO INNER EAR

INNER EAR IS LOCATED

WITHIN THE TEMPORAL BONE

MEMBRANOUS LABYRINTH

WITHIN INNER EAR ARE FLUID FILLED TUBES AND SPACES

RECEPTORS FOR EQUILIBRIUM AND HEARING ARE WITHIN THE MEMBRANOUS LABYRINTH

BONY LABYRINTH

MEMBRANOUS ABYRINTH EMBEDDED WITH THIS

THREE REGIONS OF THE INNER EAR

COCHLEA

VESTIBULE

SEMICIRCULAR CANALS

COCHLEA

WHICH HOUSES MEMNRANOUS COCHLEAR DUCT FOR HEARING

VESTIBULE

WHICH HOUSES TWO MEMBRANOUS SACS : THE UTRICLE AND SACCULE

EQUILIBRIUM REFERS TO AWARENESS OF

HEAD POSITION

VESTIBULAR APPARATUS CONSIST OF

SENSORY RECEPTORS IN UTRICLE, SACCULE, AND SEMICIRCULAR DUCTS

THE UTRICLE AND SACCULE DETECT

STATIC EQUILIBRIUM - HEAD POSITION WHEN HEAD IS STATIONARY

LINEAR ACCELERATION

THE SEMICIRCULAR CANALS DETECH

ANGULAR ACCELERATION - ROTATIONALS MOVEMENTS

EQUILIBRIUM INFORMATION ALSO HELPS TO CONTROL

EYE MOVEMENT

MACULAE OF VESTIBULE ARE LOCATED

ALONG THE INTERNAL WALLS OF THE UTRICLE AND SACCULE

THE SENSORY EPITHELIUM LINING THE TWO MACULAE CONTAINS

HAIR CELLS

WHEN MICROVILLI OF HAIR CELLS BEND WHAT CHANGES

THE AMOUNT OF NEUROTRANSMITTER RELEASED BY THE HAIR CELL CHANGES

CHANGE IN AMOUNT OD NEUROTRANSMITTER RELEASED BY THE HAIR CELLLS CHANGES WHICH THEN ALSO CHANGES THE..

ELECTRICAL ACTIVITY SENT TO THE BRAIN VIA THE VESTIBULAR NERVE

SEMICIRCULAR CANNALS ARE CONTINUOUS WITH

THE UTRICLE

RECEPTORS WITHIN THE SEMICIRCULAR DUCTS DETECT

ROTATIONAL MOVEMENT OF THE HEAD

AMPULLA

WITHIN EACH OF THE THREE SEMICIRCULAR CANNALS IS EXPANDED REGION

AMPULLA CONTAINS AN ELEVATED REGION

THE CRISTA AMPULARIS THAT IS COVERED BY AN EPITHELIUM OF HAIR CELLS AND SUPPORTING CELLS

CUPULA

THE HAIR CELLS EMBED INTO AN OVERLYING GELATINOUS DOME

WHAT HAPPENS WHEN HEAD ROTATES

WHEN HEAD ROTATES, THE MICROVILLI OF HAIR CELLS BEND AND TRANSMITTER RELEASE CHANGES THE ACTIVITY OF THE SENSORY NEURONS

COCHLEA

IS THE INNER EAR ORGAN OF HEARING

SNAIL SHAPPED

COCHLEAR DUCT

MEMBRANOUS LABYRINTH WITHIN COCHLEA

THE BONY LABYRINTH SURROUNDS

THE COCHLEAR DUCT AND IS SPLIT INTO TWO CHAMBERS

• SCALA VESTIBULI

  • SCALA TYMPANI

HAIR CELLS ARE EMBEDDED IN THE

BASILAR MEMBRANE WOTH TECTORIAL MEMBRANE PROJECTED OVER THEIR APICAL SURFACE

TECTORIAL MEMBRANE MOVEMENT IN RESPONSE TO PRESSURE WAVES

BENDS MICROVILLI OF HAIR CELLS AND RELEASES TRANSMITTER

NEURAL PATHWAY IN HEARING ( MUST KNOW)

COCHLEAR NERVE

COCHLEAR NUCLEI

INFERIOR COLLICULUS

THALMUS

AUDITORU CORTEX

GUSTATION IS

SENSE OF TASTE

GUSTATORY CELLS

TASTE RECEPTORS FOUND IN SPECIALIZED ORGANS TERMED TASTE BUDS

GUSTATORY CELLS DETECT

TASTANTS - MOLECULES AND IONS IN FOOD

PAPILLAE

THE TASTE BUDS ARE LOCATED ON THE DORSAL SURFACE OF THE TONGUE IN EPITHELIAL AND CONNECTIVE TISSUE ELEVATIONS

FOUR TYPES OF PAPPILAE

FILIFORM

FUNGIFORM

VALLATE

FOLIATE

FILIFORM PAPILAE

SMALL NURMEROUS BUMPS LACKING TASTE BUDS

FUNGIFORM PAPILLAE

MUSHROOM SHAPED BUMPS ON TIP AND SIDES OF TONGUE CONTAINING A FEW TASTE BUDS

VALLATE PAPILLAE

ROUND BUMPS ARRANGED IN A V ON POSTERIOR DORSAL SURFACE OF TONGUE

CONTAINS MANY TASTE BUDS

FOLIATE PAPILLAR

SUBTLE RIDGES ON POSTERIOR LATERAL SURFACE OF TONGUE HOUSING A FEW TASTE BUDS IN EARLY CHILDHOOD

GUSTATORY PATHWAY (MUST KNOW)

CN VII AND IX

MEDULLA OBLONGATA

THALAMUS

PRIMARY GUSTATORY CORTEX IN INSULA

OLFACTION IS

SENSE OF SMELL

ODORANTS ARE DISSOLVED IN

MUSUS OF NASAL CAVITY AND DETECTED

OLFACTION ORGANS

OLFACTORY EPITHELIUM

OLFACTORY EPITHELIUM

LINING SUPERIOR NASAL CAVITY CONSISTS OF THREE DISTINCT TYPES

• OLFACTORY RECEPTOR CELLS

• SUPPORTING CELLS

  • BASAL CELLS

OLFACTORY RECEPTOR CELLS ARE SPECIALIZED

BIPOLAR NEURONS THAT ARE PRIMARY CELLS IN SMELL PATHWAY

OLFACTORY BULBS

AXONS FROM BIPOLAR NEURONS OOF THE NASAL MUCOSA PASS THROUGH FORAMINA OF CRIBRIFORM PLATE AND ENTER….

OLFACTORY BULBS CONTAIN

MITRAL AND TUFTED CELLS

CONTAIN ABOUT 2000 OLFACTORY GLOMERULI

OLFACTORY GLOMERULI

WHERE OLFACTORY CELLS CONVERGE

OLFACTORY PATHWAY

NEURONS WITHIN OLFACTORY BULBS PROJECT AXONS BUNBLES CALLED OLFACTORY TRACTS TO OLFACTORY CORTEX OF TEMPORAL LOBE

WHAT EYES USE TO HELP FORM VISUAL IMAGES OF THE ENVIORMENT

PHOTORECEPTORS

DIAMETER OF EYE

2.5 CM

ANTERIOR CAVITY

IS IN FRONT OF THE LENS

CONTAINS CIRCULATING AQUEOUS HUMOR

BETWEEN LENS AND CORNEA

IRIS SUBDIVIDES ANTERIOR CAVITY INTO

ANTERIOR CHAMBER

POSTERIOR CHAMBER

POSTERIOR CAVITY

IS BEHIND THE LENS

CONTAINS PERMANENT VITREOUS HUMOR

BETWEEN LENS AND RETINA

FLUID IS GELATINOUS, TRANSPARENT, PARMANENT

EYE WALL HAS THREE LAYERS

FIBROUS TUNIC

VASCULAR TUNIC

RITNA ( NEURAL TUNIC )

WHAT IS LENS

IT IS A TRANSPARENT, DEFORMABLE STRUCTURE HELD BEHIND THE PUPIL BY SUSPENSORY LIGAMENTS

SUSPENSORY LIGAMENTS

ATTACH TO LENS AND WHEN THEY TENSE OR SLACKEN IT CHANGES THE LENS’ SHAPE

CHANGES IN TENSION ARE CAUSED BY

CONTRACTION AND RELAXATION OF CILIARY MUSCLES OF CILIARY BODY

FIBROUS TUNIC IS COMPOSED OF

CORNEA

SCLERA

CORNEA

TRANSPARENT

AVASCULAR LAYER THAT RECEIVES OXYGEN AND NUTRIENTS FROM LACRIMAL FLUID AND AQUES HUMOR

SCLERA

MAKES UP MAJORITY OF FIBROUS TUNIC

CONSIDERED WHITE OF THE EYE

PROVIDES SHAPE PROTECT INTERNAL PARTS OF EYE

MADE OD DENSE IRREGULAR CONNECTIVE TISSUE

VASCULAR TUNIC IS COMPOSED OF

CHOROID

CILIARY BODY

IRIS

CHOROID

CONTAINS VAST NETWORK OF CAPILLARIESS SUPPLYING NUTRIENTS AND OXYGEN TO THE RETINA

CILIARY BODY

COMPOSED OF CILIARY MUSCLES AND CILIARY PROCESSES

CHANGES LENS SHAPE

IRIS

PIGMENTED PART OF THE ANTERIOR EYE

DEFINES PUPIL CONTROL AMOUNT OF LIGHT ENTERING EYE

RETINA ( NEURAL TUNIC )

MADE UP OF PIGMENTED LAYER AND NEURAL LAYER

PIGMENTED LAYER

ATTACHED TO CHOROID

ABSORBS LIGHT THAT PASSES THROUGH REITNA

NEURAL LAYER

HOUSES PHOTORECEPTORS AND ASSOCIATED NEURONS

RECEIVES LIGHT

CONVERTS ENERGY INTO NERVE IMPULES

PHOTORECEPTOR CELLS IN NEURAL TUNIC

OUTERMOST LAYER COMPOSED OF RODS AND CONS

GANGLIION CELLS IN NEURAL TUNIC

INNERMOST LAYER OF THE RETINA

AXONS OF THESE CELLS LEACE THE RETINA AND FORM THE OPTIC NERVE (CN2)

RODS

IMPORTANT IN DIM LLIGHT

CONS

IMPORTANT FOR PRECISE VISION AND COLOR

OPTIC DISC

BLIND SPOT

LACKS PHOTORECEPTORS

LOCATED WHERE GANGLION CELL AXONS RETINA TO FORM OPTIC NERVE AND BLOOD VESSELS ENTER AND EXIT THE RETINA