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

2. What are the types of cutaneous sense organs? Nervous System (Senses)

3. 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

4. The Senses: Balance Kinetic labyrinth Responds to movement of endolymph (fluid) in semicircular canals i.e. angular (rotational) acceleration Nervous System (Senses)

5. The Senses: Balance Static labyrinth Responds to force of gravity and linear acceleration Nervous System (Senses)

6. The Senses: Hearing Auricle collects sound waves External auditory meatus (canal) channels sound waves Tympanic mem. & ossicles conduct sound waves Nervous System (Senses)

7. The Senses: Hearing The oval window transfers sound waves to the liquid inside the cochlea Three scala: vestibuli media (cochlear duct) tympani Nervous System (Senses)

8. The Senses: Hearing Sound 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)

9. The Senses: Hearing Basilar 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)

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

11. 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)

12. The Senses: Gustation (taste) Types of papillae: Circumvallate Foliate Fungiform Filiform (most numerous but NO taste buds here. Foliate papillae Nervous System (Senses)

13. The Senses: Gustation (taste) Salty Nervous System (Senses)

14. What are the layers of the eye and what are their functions? 3 distinct layers of tissue in eye: Fibrous Sclera & cornea Vascular Choroid, iris etc. Nervous Retina Clear light pathway Nervous System (Senses)

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

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

17. 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)

18. 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)

19. How is light converted into action potentials? 3 neuronal layers of the retina: Photoreceptors Also bipolar neurons and Ganglionic neurons Nervous System (Senses)

20. Are all photoreceptors created equally? Rods (~120 million each) Cones (~6-7 million each) Nervous System (Senses)

21. 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)