Wk6- The Special Senses

Special senses are the most complex senses. They enable us to perceive ourselves and environment around us (survival and vitality) What are the 5 special Senses?

Olfactory structure How do olfactory receptors detect odourants? Exhalation or Inhalation?

Olfactory structure Odourant is dissolved in secretion from epithelium in the nasal cavity, also known as the - gland ?

Olfactory structure Odourants bind to - - ?

Olfactory structure Information of stimuli is sent to the olfactory region of the brain and limbic system via the o? b?

Olfactory receptors: C? receptors Humans have _ _ million Ad_p_at_ _n is the adjustment / lowering perception of smell

Gustation The tongue has both taste buds and taste - . What other sensory receptor also contributes to taste?

Gustation The tongue is covered with lingual -? There are 4 types, they are?

Gustation Food is dissolved in saliva. Saliva enters the taste p? and the tastant binds to receptor sites of the - - .

Gustation Gustatory receptors stimulate neurotransmitter. The signal travels to the gustatory area in the P- lobe of the Ce-

Gustatory receptors • • • • • • receptors • Gustatory hairs (micro villi)

Gustation The 5 primary tastes are ?

Vision Vision is the most important sense. Light passes through the - projected on the - via the -.

Vision Light rays are converted into nerve impulses by - receptors. Sensory information is then sent to the - lobe.

Visual receptors Photoreceptors in the - retina are made up of - (10 million) and - (5 million)

Vision: photoreceptors ? - sensitive to light - no colour detected - concentrate periphery of retina ? • detect colour • concentrate centre of retina

Equilibrium Utilises the - , pro? and vestibular complex in the -

Equilibrium The vestibular complex is used for both static and dynamic movement. The utricle and saccule in the - are used for static movement. The anterior/posterior/lateral - are used for dynamic movement.

Equilibrium Detection of static movement 1.Specialised hair cells - cilia 2.otoliths 3.inner ear -

Equilibrium Detection of dynamic movement : 3 semi circular canals -, -, and lateral - fluid in canals deflected by way of movement When the c? fluid is stationary = balance

Equilibrium receptors 1. - receptors 2. Hair cells These receptors detect the position of the head Detection takes place in the - ear (macula & canals)

Hearing Like equilibrium , hearing is also detected in the - -? But also in the - ear. The - - detects - waves.

Hearing Hearing vibrations pass through a sequence 1. The Middle ear : auditory - And then 2. The inner/internal ear : cochlea -> receptor cells Sound waves cause basilar membrane in the cochlea to vibrate

Hearing Sound waves travel along the basilar membrane High frequency sound waves travel a - distance Low frequency sound waves travel a - distance Hair cells on the basilar membrane pick up the wave length