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Human- endoskeleton made of bone tissue, bones grow constantly
all vertebrates have this type advantage to growth disadvantage internal equals less protection

Arthropods and mollusks- exoskeleton, protects and molts

Hydrostatic- squirms animals like worms, internal water pressure

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General Structure
Muscle
bundle of fibers
single fiber
myofibril
each muscle is a bundle of muscle fibers
- each fiber is a bunch of multi-nucleated cells
-each cell has a collection of myofibrils
each myofibril is packed with actin (thin) and myosin filaments

Skeletal- voluntary motion
- arranged in antagonistic pairs (extensor and flexor ie. bicep and tricep?)
Smooth- lines organs/ involuntary
Cardiac- heart/ involuntary

Sliding Filament Theory
ATP is hydrolyzed to move myosin between active and inactive conformation
active myosin bonds to actin forming a cross bridge that pulls it toward the middle of the sarcomere
inactive- myosin remains attached to actin until ATP hydrolysis occurs again
sliding filament
actin and myosin slide past each other, binding sites not always open
- if we don't send the signal muscle cells not in action
Nervous system interfaces with muscle tissue at neromuscular junction
Actin- calcium must be present in the sarcomere and bonded to tropomyosin for myosin to bond to actin
- stored in region of sarcomere called the sarcoplasmic reticulum

THE STEPS
1. acetylcholine binds to muscle receptor (lets Ca++) propagates signal
2. signal sent through fiber to T tubule
3. signal in t tubule triggers release of Ca++ from the sarcoplasmic reticulum (moves via facilitated diffusion High to low concentration)
4. Calcium binds to troponin complex and opens the myosin binding sites
5. ratchet- ATP changes shape
6. ATP powers calcium pump to move CA back into SR active low to high
7. movement of Calcium back into the SR causes muscle to relax

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Touch- mediated by receptors in the skin, temperature pain pressure hair movement,
- action potentials are binary/ spatial and temporal pattern of signals is what determines sensation
- gentle pressure = low frequency
- high pressure = high frequency

Sight- photo receptors
- eye spots in planaria
- very primitive- drives movement as long as light is shining on either eye spot (ocellus)
- causes negative photo-taxis
Compound arthropod eye
- each eye contains many individual facets
- each facet has one fixed lens and one photo-receptor
Vertebrate eye
- cilliary muscels contract pulling boarder of choroid to lense, suspensory ligaments relax
- lense becomes thicker and rounder focusing on nearby objects
rods- interpret the presence or absense of light
cones respond to different wavelengths of light

Sound
mediate by receptors that vibrate in response
Mammalian Ear
- pinna, tympanic membrane, malleus, incus, stapes
ear consists of a canal to direct soundwaves and a series of bones and organs that interpret those waves as heard sound
- much of hearing is due to hair cells that line the cochlea and vibrate at particular frequencies
- hair cells and ear anatomy are also involved in the detection of spatial positioning of the body and subsequently balance
- arthropods have tympanic membranes on the forelegs of the organism

Chemoreception
- in animals mediated via taste and smell moste animals sense the environment via chemoreception

Taste
interpret molecules as different tastes food tastes good
-genetic (cilantro?)

Smell
smell is interpreted when oderants interact with receptors on the cell membranes of chemoreceptors that protrude from the olfactory bulb of the brain
-vastly less pronounced in humans
-important in taste as well

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gray matter- cell bodies nerve terminals dendrites
white matter- axons

Frontal lobe- control of skeleton, motor cortex, prefontal cortex (decision making/planning) Brocas area (speech formation)

Parietal Lobe - somato-sensory cortex (integration of sensory information) sensory association cortex (integration of sensory information)

Occipital lobe- visual association cortex combining images and object recognition, visual cortex (processing vision)

Temporal Lobe- Wernicke's (comprehending language)

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Central- brain and spinal cord
Peripheral- nerves ganglion etc

Afferent- input into the CNS from internal/ external stimuli to sensory nerves
Efferent- outgoing nerve signals to autonomic and motor systems

Sympathetic- Fight or flight relax bronchi, accelerate heart inhibit activity in stomach etc
Parasympathetic- reverses sympathetic response, slows down

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Imprinting- young animals go through a critical period, they copy the animals present in that period. ex. young geese and birds.
Spatial- establishment of memories that reflect the physical structure of the environment. ex. wasps use pine cones to remember nest location.
Cognition- most complex types of learned behavior. ex. bees can remember same vs. different.
Associative- connecting 2 environmental features. ex. birds associate eating monarch butterflies with vomiting.
Social- learning by interacting with others. ex. young chimpanzees learn to crack nuts open by watching older chimpanzees.

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1) Neuron at rest; all gated channels closed.
2) Neuron depolarizes; Na gates begin to open.
3) Rising Phase of A. P.; Na gates all opened.
4) Falling Phase of A.P.; Na gates shut, K gates open.
5) Undershoot; K gates start to close.