Steps to Muscle Contraction Quiz

How a Muscle Contracts and Relaxes!!!!!
1. An electrical signal (action potential) travels down a nerve cell, causing it to release a chemical message (neurotransmitter) into a small gap between the nerve cell and muscle cell. This gap is called the synapse or synaptic cleft.

2. The neurotransmitter (Ach) crosses the gap, binds to a protein (receptor) on the muscle-cell membrane and causes an action potential inside the muscle cell.

3. The action potential rapidly spreads along the muscle cell and enters the cell through the T-tubule.

4. The action potential causes gates to open in the muscle's calcium storage warehouse known as the (sarcoplasmic reticulum).

5. Calcium ions flow into the cytoplasm, which is where the actin and myosin filaments are.

6. Calcium ions bind to troponin-tropomyosin molecules located in the grooves of the actin filaments. Normally, the rod-like tropomyosin molecule covers the sites on actin where myosin can form crossbridges.

7. Upon binding calcium ions, troponin changes shape and slide tropomyosin out of the groove, exposing the actin-myosin binding sites.

8. Myosin interacts with actin by cycling crossbridges, as described previously. The muscle thereby creates force, and shortens. This uses energy….

9. After the action potential has passed, the calcium gates close, and calcium pumps located on the sarcoplasmic reticulum remove calcium from the cytoplasm via active transport.

10. As the calcium gets pumped back into the sarcoplasmic reticulum, calcium ions come off the troponin.
11. The troponin returns to its normal shape and allows tropomyosin to cover the actin-myosin binding sites on the actin filament.

12. Because no binding sites are available now, no crossbridges can form, and the muscle relaxes.

12-11 AP Period 2

In class:
Journal
Collected muscle cell drawing projects
Finished notes on muscle cell contraction physiology
Did the muscle cell physiology steps worksheet

Quiz next class:
muscle cell physiology steps
muscle vocabulary:

here are the words you will be expected to match the definition to:
endomysium
epimysium
fascia
fascicle
myosin
perimysium
sarcolemma
sarcomere
sarcoplasm
sarc reticulum
tendon
transverse tublule
origin
intsertion
prime mover
antagonists
synergists

Wed and Thursday 12-9 and 12-10

In Class
Journal
quiz on muscle cell parts period 2 only period 5 and 6 will have it next class
Here is what the quiz will be on:

images 8.1, 8.3, 8.7 labeling and being able to define

look up the words: origin, insertion, prime mover, antagonist, synergist
notes on muscle physiology

HW
Muscle cell projects are due next class

Mon and Tues 12-7 and 12-8

In Class
journal
assigned and explained muscle presentation
finished your muscle cell drawing projects

HW:
muscle cell drawing projects are due Fri for P2 and Monday for P5 and 6
Study for the muscle cell anatomy quiz next class pay attention to:
images 8.1, 8.3, 8.7

look up the words: origin, insertion, prime mover, antagonist, synergist

Tuesday and Wed 12-1 and 12-2

In Class
Journal
Notes on muscle cell anatomy

HW:
See blog for list of bones that are on the quiz you are having next class
Muscle worksheet
Muscle coloring packet