1. Chapter 49: Sensory and Motor Mechanisms

3. Receptors Differing types of sensory receptors (focus on the prefixes)
- Mechanoreceptors- Physical deformation (touch, sound)
- Chemoreceptors- Chemical changes (taste, smell)
- Electromagnetic- Photoreceptors for light (sight)
- Thermoreceptors- Heat, cold
- Pain receptors

5. Hearing (closely related to balance)
- Some inverts have statocysts with associated statoliths while others have vibrating hairs or tympanic membranes

6. Hearing
Mammals
Hearing: Pressure (air) waves travel through the air, strike our tympanic membrane, transferred to the inner ear and then vibrate small hairs with associated neurons
Equilibrium: Small hairs change position based on the movement of a gel that surrounds them

9. Smell/Taste -Smell: Cilia in our noses trigger action potentials
- Taste: Taste buds on the tongue are triggered by chemicals in the food (will cause gates in the cells to open and chemical influxes)

12. Vision Photoreceptors are very similar throughout the animal kingdom
- Inverts: Lower inverts will only sense light intensity and/or direction while higher inverts can have complex compound eyes

13. Vertebrate Vision
- The retina houses both rods (sensitive to only black /white and light intensity) and cones (sensitive to color only).
- These sensory receptors make up 70% of all the sensory receptors in the body.
- Both the rods and cones make synaptic connections with associated neurons
- 30% of the cerebral cortex is used to formulate what is being seen

16. Skeleton Skeleton- Support, protection, movement. 3 types:
1. Hydrostatic- Fluid is held under pressure in a closed body compartment
2. Exoskeleton- Calcium carbonate and/or chitin (kīt'n)
3. Endoskeleton- Hard, supporting elements buried in soft tissue

17. Muscles Muscles- Protein strands sliding against each other. 3 types:
1. Cardiac- Heart only
2. Smooth- Digestive system, used for peristalsis.
3. Skeletal- Movement

18. Muscles - Muscle fibers are called myofibrils
- The repeating units that can be found in the myofibrils are called sarcomeres.
- If we look at one sarcomere we will find…
- Myofilaments made of…
- A thick filament (myosin)
- A thin filament (actin)

20. Muscles - Sliding filament model of muscle contraction (tetanus)
- Myosin (thick filament) will “claw” along the actin (thin filament)
- Ca2+ has to be present for the muscle to contract. When not present, the muscle will be at rest.
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