Connective Tissue Coverings
Skeletal Muscle Fiber Structure
The Sarcomere
Energy Metabolism
What Type of Muscle Tissue am I?
Excitation-Contraction Coupling
100

This CT layer covers each individual muscle fiber.

Endomysium

100

This is the name for the cytoplasm of a muscle fiber.

Sarcoplasm

100

The sarcomere is the repeating functional unit of skeletal muscle contraction. It is composed of thick and thin filaments made of these 2 proteins.

Thin filament = actin

Thick filament = myosin

100

The energy currency of the cell

ATP

100

I have multiple nuclei, striations, and a long cylindrical shape.  I function to produce voluntary movement, produce heat, and protect organs.

Skeletal Muscle

100

This is the fluid filled gap between the axon terminal of a motor neuron, and the muscle fiber it innervates. Neurotransmitters are released in this space.

Synaptic cleft

200

This CT layer covers each individual muscle and is deep to the fascia.

Epimysium

200

This fiber-like organelle is made up of repeating subunits of myosin and actin.

Myofibril

200

This portion of the sarcomere is where thick and thin filaments overlap, and is also called the "dark band" 

A Band

200

Sally is running a 10 mile race.This is the most likely pathway her muscles are using for ATP regeneration.

Aerobic respiration

200

I am uninucleate, have striations, and intercalated discs. I function to pump blood through blood vessels.

Cardiac Muscle

200

This is the neurotransmitter that stimulates muscle contraction.

Acetylcholine

300

This is the connective tissue that attaches muscles to bones.

Tendon

300

This organelle stores and releases the calcium ions involved in muscle contraction.

Sarcoplasmic reticulum

300

A contractile unit

What is a sarcomere?

300

Where does aerobic respiration take place in the muscle cell?

Mitochondria

300

I am the muscle tissue shown here

Smooth Muscle

300

Calcium released from the sarcoplasmic reticulum floods the muscle fiber and binds to this protein in order to expose the active sites on actin filaments.


Bonus: what is the name of the other accessory protein that actually moves out of the way to espose active sites?


Troponin

Bonus: tropomyosin

400

This CT layer covers each fascicle.

Perimysium

400

This specialized structure controls what enters and exists the muscle fiber. It has projections, called T-tubules, that extend deep into the muscle fiber.

Sarcolemma

400

Which number represents the I band?

7 - The light band where there are only thin actin filaments.

400

What is the waste product which is produced when anaerobic respiration takes place in your muscle cells?

lactic acid

400

Smooth muscle produces this wavelike motion that propels food down the G.I. tract.

Peristalsis

400

This temporary structure is formed between myosin heads and actin. It is the formation of this structure, and the power stroke of myosin, that causes sarcomere shortening (AKA contraction).

Cross-bridge

500

Name one of the two main functions of the connective tissue wrappings of muscles.

1. Separate and organize parts of skeletal muscle

2. provide entry and exit point blood vessels & nerves

500

This the neurotransmitter which is released from a motor neuron which crosses the synaptic space to bind to a receptor in the sarcolemma which will initiate an impulse that travels to the T-tubule.

Acetylcholine

500

When a muscle fiber contracts the sarcomere does this as thin filaments are pulled over thick filaments within the structure.

Shortens

500

This is the number of ATP molecules generated from one glucose molecule during aerobic respiration (cellular respiration).

36-38 ATP

500

I am the muscle tissue seen here.

Cardiac muscle

500

After a contraction, the muscle fiber will relax in the presence of ATP. Calcium will be transported back to the sarcoplasmic reticulum, sodium concentration will be brought back to normal levels ending the action potential, and this enzyme will destroy all the acetylcholine left in the synaptic cleft to ensure stimulation of the muscle fiber has ended.

Acetylcholinesterase