muscular system khan academy

The only way that we could stop the block of the myosin head from crossing over the actin is

by changing the conformation troponin, and moving tropomyosin out of the way

smooth muscle

hallow organs and blood vessels "Aorta" + involuntary + eye shaped * spindle shape with 1 nuclei

Autonomic Nervous system is divided into

involuntary SYMP= noradrenaline, norepinephrine " fight or flight" PARAS= Acetocholine, rest and digest

what could a tropomyosin do to the actin

it could block the myosin head from moving into the actin

What is the role of tropomyosin in muscle contraction?

To prevent myosin from continuing to slide up the actin filament

tropomyosin could block the myosin head from crossing the actin

true

Somatic Nervous System

voluntary and acetocholine

sarcoplasmic reticulum

when the muscle contracting, the Ca++ from the SR gets out into the cytoplasm when the muscle relaxes, the Ca++ from the SR gets inside of the SR SR: is a storage place for Calcium!

A band

when the sarcomere contracts: I band change A band doesn't change and stays the same.

If injury happens to the UMN, what could potentially happen?

* weakness doesn't happen since there is no stop sign, the start keeps sending the signal. This causes spastic behavior in the muscle, this leads to constant contraction.

parts of the brain that control voluntary

*cerebral cortex *and spinal cord

PNS, myelin called:

*schwan cells

If injury happens to the LMN, what could potentially happen?

*weakness could result

neuron

+ dendrites receives signals * myelin sheath: insulates the signal (FAT) + axon: send the message though it + node of Ranvier: empty space that the signal jump though

How does the actin and myosin works?

1) ATP binds to myosin head 2) myosin still has the ATP but got released from actin 3) ATP now gets hydrolyze to ADP and PI but still attached to the myosin 3) PI gets released from the myosin but it is still attached to the ADP, now it pushed the actin and ADP also gets releases 4) it goes back to step 1 but 1 step further!

Type 1 muscle fibers

1) Red 2) contraction speed: slow 3) conduction: slow 4) aerobic activity 5) duration: long 6): Fatigue not easily 7) power: strong 8) In the form of triglyceride fatty acid. golden role: Type 1 contains lots of mitochondria

What is an aponeurosis?

A large, flat tendon that anchors muscle

The hydrolysis of the ATP that is bound to myosin causes: Please choose from one of the following options.

Release of myosin head from the actin filament

How does your brain tell your brain to move your leg when dancing?

Brian tell (UMN) to send a signal to the (LMN) UMN has two jobs: start + stop LMN has one job: start only

Curare is a naturally-occurring compound that competitively binds to nicotinic acetylcholine receptors on muscle cells. Which of the following symptoms might be seen in a patient who has been exposed to curare? Excessive salivation Muscle spasticity Diaphragmatic paralysis Cardiac arrest

Diaphragmatic paralysis

Which of the following correctly identifies muscle components in order from largest to smallest? Please choose from one of the following options.

Fasciculus, muscle fiber, myofibril

What is the role of acetylcholine in calcium release? Please choose from one of the following options.

Stimulates cellular contraction by opening voltage-gated ion channels

Which of the following is NOT innervated by the autonomic nervous system? Branching muscle cell Striated muscle cell Myocardial cell Intestinal muscle cell

Striated muscle cell, skeletal muscle (voluntary)

cardiac muscle

The only type of muscle in the heart. involuntary -branched, 1 or 2 nuclei -located in the middle of the cell -striated

what two types of muscles have stripes

cardiac and skeletal

How do you employ myosin head? inotropy

either increase the calcium level or make the troponin C more sensitive to calcium.

what is the space between the two Z lines

sarcomere

what two types of muscle have in voluntary control

smooth and cardiac

skeletal muscle

tendon + bone aponeurosis + muscle voluntary It is the fastest muscle Branched of nuclei, striated, found in the periphery.

Syncytium

the muscles are in synergy with each other when one contracts it causes the neighbor to contract as well. The entire neighborhood contracts together now.

CNS, myelin is called:

* Brain and spinal cord. Oligodendrides

part of the brain that controls involuntary

* Brain steam * sympathetic ganglia (BEHIND ME)

how does the troponin and tropomyosin works? both: protein.

1) if the calcium concentration goes low, the ca++ gets released from the troponin= this cause muscle relaxation 2) if the calcium concentration is high, the the Ca+ gets attached to the troponin and would help the myosin head bind to the actin so that it could cross over which would lead to muscle contraction.

Neuromuscular Junction

1) influx of Ca++ into the axon terminal 2) Ca++ binds to the NT 3) NT fuses with synaptic cleft 4) exocytosis happened 5) NT binds to the nitcotinic receptor causing Na+ open and ACTH enters (endocytosis) 6) As each NT enters, Na+ also enters this causing depolarization. 7) Most of the calcium gets hidden in SR ---When it enters called "calcium Induced Calcium release" 8) Now the muscle cells contract ( gap junction) all cations follow from one muscle to another

what are the 3 types of muscle?

1) smooth 2) cardiac 3) skeletal all known to have some type of movement

Type 2 muscle fibers

1) white 2) contraction speed: fast 3) conduction: fast 4) anaerobic activity 5) duration: slow 6): Fatigue easily 7) power: weak 8) ATP and creatine phosphate golden role: Type 1 contains lots of mitochondria

We would expect to find smooth muscle in all of the following EXCEPT: Please choose from one of the following options. Myocardial tissue Pulmonary circulatory tissue Esophagus Small intestine

Myocardial tissue

when is myosin head happy and when is unhappy?

Myosin head is happy when calcium is around because then it could bind to actin to form contraction, if calcium not around the the head is controlled by tropomyosin and there wont be contraction happening or it won't bind the actin molecule.

There are how many types of troponin, and to what type the ca++ binds?

Type C, I, T calcium binds to type: C

Which of the following is accurate regarding Type I and Type II muscle fibers?

Type I fibers store much of their energy as triglycerides, whereas Type II fibers store energy as ATP or creatine phosphate