Exam #2 Ch. 6.txt

• Smooth
• Cardiac
• Skeletal

• Single nucleus
• No striations, hollow organs/blood vessels (gap junctions)
• Involuntary
• Slow/long contraction (do not contract at once)

• Single nucleus (per cell)
• Branched nucleus
• Striations
• Heart wall
• Intercalated disks

Plasma membranes jam packed with gap junctions passing back and forth through the cell

• Multinucleated
• Striated
• Voluntary
• Attached to skeleton
• Cells run entire length of muscle

• 1. Support body
• 2. Make bones move
• 3. Help maintain body temperature
• 4. Help cardiovascular/lymphatic vessel movement
• 5. Protect internal organs
• 6. Stabilize joints

Animals whose muscle is outside of vertebrae

• Tendon
• Origin - lesser mobile bone (ex: end next to ball-and-socket joint)
• Insertion - more mobile bone (ex: closer to hinge (elbow))

• 1. Size
• 2. Shape
• 3. Location
• 4. Fiber direction
• 5. Attachment
• 6. Number of attachments
• 7. Action

Pull insertion closer to origin

• Prime mover � main moving muscle
• Synergist � working together in the same movement
• Antagonist � opposite movement

• Whole muscle --> Muscle bundle (fascicle) --> Single muscle cell (fiber) --> myofibril --> myosin, actin, sarcomere, z-line

• Sarcolemma: plasma membrane (plasmalemma)
• Sarcoplasm: cytoplasm
• Sarcoplasmic Reticulum: endoplasmic reticulum
• T-Tubule: stored calcium (made of sarcolemma)

• Glycogen for ATP
• Lots of mitochondria
• Sarcolemma
• Synaptic cleft (junction between 2 cells)
• Acetylcholine in vesicles

• Step 1:
• Nerve impulses arrive
• Acetylcholine (ACh) is released (neurotransmitter) by exocytosis
• Step 2:
• Ach in synaptic cleft
• Binds to receptors in sarcolemma
• Impulses spread along sarcolemma
• Travels down t-tubule
• Arrives in sarcoplasmic reticulum where calcium is stored
• Step 3:
• Calcium released from SR
• Binds with troponin
• Causes shift in tropomyosin
• Biding sites on actin exposed
• Myosin binds to actin
• Step 4:
• Myosin bends and pulls actin
• ATP energy used
• Calcium unbinds
• ATP binds/energy used
• Myosin detaches from actin
• Process repeats and muscle shortens

• Contracting but not relaxing
• Dehydrated
• Imbalanced ions

• Made from botulism
• No muscle contraction

• No ATP is released for relaxation
• Rigor mortis goes away�.EVENTUALLY
• Lysosomes begin destroying proteins making everything detach

• Found in dirt
• If puncture in a place of no oxygen, releases toxin
• Produces exotoxin
• Prevent muscle relaxation
• Makes us contract so much that we begin breaking bones

Motor neuron and all muscle fiber it innervates (controls)

• Muscle fiber ratio
• Axons controlling smaller amounts of fiber have more controlled movements
• Axons controlling more amounts of fiber have more strength in movement
• Eye muscles 1:23
• Leg Muscle 1:1000

Muscle fibers that the axon is connected to will all contract or none of them will contract

• "Dark" meat - leg and thigh
• More blood vessels
• Myoglobin stores oxygen
• Aerobic (move to mitochondria and make lots of ATP)
• Breaks down ATP slowly and continuously
• Long-term exercising
• High endurance

• "White" meat - breast and upper wing
• Short-term contraction
• Explosive
• Fatigues easily because it uses all ATP quickly
• Anaerobic (without oxygen)
• Less mitochondria
• Strength

• Before:
• Increase heart rate for oxygen going to muscle
• Decrease risk of pulling muscle
• After:
• Increase range of motion
• Cool down:
• Need to keep blood flowing by decreasing intensity of exercise
• Extra blood flow to decrease lactic acid
• Need ATP