Anatomy and physiology exam 3

Be able to identify structures of a skeletal muscle. Where is the mitochondria,transverse tubules, sarcoplasmic reticulum, myofibril and sarcolemma located?

What does the Sarcoplasm reticulum Retain? What does it release to cause a muscle contraction? What causes it to release the substance?

It retains and stores calcium and is released due to a nerve impulse that reaches the fiber, causing ATP to travel along the sarcolemma then the ttub that then activate proteins linked to the calcium Channels on it, causing it to open

Lecture explanation

Cirstenae (part of sacroplasmic reticulum )concentrates and releases, calcium into sacromeresto begin muscle contractions. This is triggered by the action potential coming in from the nerve that flows through the sarcolemma in through the T tubules that released calcium from the sarcoplasmic reticulum.

What is the structure and function of the epimysium

Structure: Surrounds the muscle organ and has an exterior collagen layer connected to a deep fascia

Function: Separates muscle from surrounding tissue

Perimysium

Structure: Surrounds the muscle Fascicle

Function: Contains blood vessels and nerves that will feed and innervate myofibers

Endomysium

Structure surrounds the muscle cell(myofiber)

Function has capillaries and nerve fibers that feed and contact myofibers

Also has myosatellite cells that repair myofiber damage

sacromere

Structure: Structural units of myofibrils form stripes

Function it is the contractile unit units of muscles

sacrolemma

Structure plasma membrane of the mayo fiber

Function change in the transmembrane potential leads to contraction cycle

Sarcoplasmic reticulum

Structure: membranous structure that surrounds each myofibril

Function-helps transmit AP to myofibril

Releases calcium and retain

Fascicles

Structure : muscle fiber bundles

Function contract, and make force

Myofilaments

Structure within myofibrils and part of sacromere

Function protein filament is responsible for muscle contractions/sliding filament theory

What is a thick filament?

Made of the protein myosin that are dark filaments in A band

What is a thin filament

Made of protein acting that are light filaments I band

How is action potential propagated from the surface to the interior of a muscle fiber? What is the conduit?

Skeleton muscle contracts, when stimulated by mortar neuron in neuromuscular junction, then the AP at the synthetic terminal causes acetylcholine to release into the synaptic cleft which diffuse and binds and open sodium channels that lead to the production of action potential in the sarcolemma that tracks along the t tubules to triads where it triggers the release of calcium ions from the terminal cirstenae of sarcoplasmic reticulum= construction cycles begins the conduit is the TTubules

What is the sequence for contraction of a skeletal muscle?

Neuromuscular junction, then excitation contraction coupling then Crossbridge cycle

The contraction cycle

Tropomyosin shifts leaving the active site exposed then the Cross-bridge forms and the myosin head pivots which advances power strokes(pulls the actin towards center which shorten sarcomere this is the muscle contraction), the Cross bridge detaches, and myosin reactivates

What is the primary neurotransmitter? It is released in the new

Acetycholine

What is troponin?

Troponin is a globular protein that works with tropomyosin and regulates binding affinity of tropomyosin for globular actin structure is modified by binding calcium. This bonding relaxes tropomyosin, exposing the active site on actin that works with myosin to start contractions.

Tropomyosin

is a fibrous double-stranded protein that when the muscle is at rest, it prevents actin and myosin interaction by covering up the active site of actin

Aerobic respiration

This is the primary energy source of resting, skeletal muscle. It uses fatty asses and glycogen.

Anaerobic respiration

Peak muscular activity that uses carbs, lipid Animo acids

It transforms pyruvate to lactic acid and uses glycolysis for ATP known as the Cori cycle

What is the I band?

Only actin filaments are on it. ends of sacromere marked by Z on I band

What is the H band?

Area around M line the only has thick filaments

What is the Zline?

are at the middle of the I band, defines the two ends of the sacromere

Zone of overlap

Dens and darkest area on light microscope, thick and thin, filaments overlap

M line

Is the center of the a band and middle of the sacromere

What structure gets larger during muscle contraction

The I band and the h zone gets small smaller

What do anabolic steroids do?

They stimulate contractile protein synthesis and muscle enlargement. They are similar to testosterone, but have detrimental side effects.

What is atrophy?

Muscle Shrinkage due to the lack of muscle activity which reduces muscle size tone and power

Hypertrophy

Muscle growth from strenuous physical exercise, which increases the diameter of myofibers not the number of them

hyperplasticity

Increase the number of myofibers due to hyperplasia -growth of the muscle tissue by number of muscle fiber rather than the size

You are working out with weights after a while you noticed that your muscles are becoming larger. What is the best explanation?

Muscle hypertrophy the muscle fibers diameters have increased anaerobic training Has fast fibers that fatigue quickly with strenous activity which causes hypertrophy and then improves frequent brief intense workouts

What is a sphincter?

A ring of muscle that surrounds and serves to guard or close and opening or tube an example is the anus

From the PowerPoint, it says a controls the movement of materials through the urethra and anus

Agonist

Produces the prime movement

Antagonist

Contradicts the movement caused by the agonist

Synergist

Assist the larger agonist to start motion

Difference between the agonist and the antagonist

When one contracts the other relaxes

Oblique muscles

Lies within the body wall, which compresses the underlying structures and flexes and rotates vertebral canal

Transverses

Deepest layer of abdominal muscle muscles wrapping around the trunk and assisting in core stabilization

Medialis

Towards the midline of the body

Lateralis

Away from the Midland

Rectus

Lies within the body wall, straight muscles that flex the vertebral column and oppose the erector spinae muscles

These muscles are called "rectus" because their fibers run straight along the body part they are located in and have straight parallel alignment

If you sever the tendon that attaches to the point of insertion of the biceps brachii, what action would be difficult to perform?

Elbow flexion and forearm supination

What is the kissing muscle?

Orbicularis oris

Which eye Muscles are intrinsic

Collard muscle, Iris spincter, and radio pupil dilator

What eye muscles are extrinsic

Inferior medial superior and lateral rectus along with inferior and superior oblique

What does the sternocleidomastoid do?

Flexes and rotates the neck. Not head and pull head down to either shoulder.

You look down at your shoes what eye muscle are you using?

Inferior rectus

As a surgeon, you make an incision that is parallel and lateral to the linear Albea the midline of the abdominal area. What muscle are you cutting

Rectus abdomen is

Were powerful muscle abduct the shoulder

Del toy and the supraspinatus is a helper

What are the rotator cuff muscles?

Super spinatus, subscapularis, infraspinatus, and teres minor

What muscle extend the forearm?

Triceps Breaky

What muscle Dorsiflexes the foot?

tibialis anterior

What muscles composed the quadriceps

The quadriceps femoris Has rectus femoris vagus lateralis medialis and intermedius

The biceps group

Biceps brachi brachioradialis brachialis coracobachialis

The tricep group

Triceps brachi lateral long and medial head

Anconeus

Playing trouble, your tackled heart, and have difficulty getting up trouble flexing your leg. What muscle could you have injured?

The hamstrings

Biceps femoris

Seminembranosus

Semitendinosus

Popliteus

What is the strongest jaw muscle used to elevate the mandible

Masseter