AP1 final

3 Types of Muscle Tissue

skeletal muscle, cardiac muscle, and smooth muscle

Skeletal Muscle Cell \=

MUSCLE FIBER

Skeletal Muscle Tissue

\

Cardiac Muscle Tissue

Smooth Muscle Tissue

Epimysium

Dense sheath of collagen fibers around the muscle.

Muscle Fascicle

Bundle of muscle fibers.

Perimysium

Fibrous layer dividing muscle into compartments.

Endomysium

Thin layer of areolar connective tissue around each muscle fiber

MYOSATELLITE CELLS

Stem cells that help Repair Damaged Muscle Tissue

What separates muscle Fascicles?

Perimysium

What contains blood vessels and nerves supplying muscle fibers?

Perimysium

Epimysium, Perimysium, and Endomysium merge to form a

Tendon or Aponeurosis.

Tendon

Attaches muscle to a specific point on a bone.

Aponeurosis

Broad sheet with a broad attachment to bone(s).

SKELETAL MUSCLES CAN BE CATEGORIZED BASED ON THE ORGANIZATION OF THEIR

FASCICLES

FASCICLE

Bundle of muscle fibers within a skeletal muscle.

PARALLEL MUSCLE

Fascicles parallel to long axis.

What muscle has a central body (belly)

Parallel Muscle

Most skeletal muscle is what type of muscle?

Parallel muscle

CONVERGENT MUSCLE

fascicles extending over Broad Area Converge on common attachment site.

VERSATILE

Different Parts can pull in Different Directions

PENNATE MUSCLE (penna, feather)

Fascicles form ANGLE with tendon. Tendons move less than a parallel muscle

More fibers and myofibrils than parallel muscle, produces more tension

Pennate muscle

3 types of pennate muscles

Unipennate, Bipennate and Multipennate

UNIPENNATE

All fibers are on one side of tendon (extensor digitorum).

​BIPENNATE

Fibers insert on both sides of tendon (rectus femoris).

​MULTIPENNATE

Tendon branches within pennate muscle (deltoid).

CIRCULAR MUSCLE or SPHINCTER

Fascicles in CONCENTRIC CIRCLES.

Contraction

DECREASES DIAMETER of opening (constricts)

Myoblasts

Embryonic cells that fuse to form multinucleate cells that differentiate into skeletal muscle fibers.

Sarcolemma

Plasma Membrane.

Sarcoplasm

Cytoplasm.

Myofibril

Run Length Of Muscle Fiber.

Myofilaments

Bundles of protein filaments inside myofibrils

Thin Filaments

mostly composed of ACTIN.

Thick Filaments

mostly composed of MYOSIN.

SARCOMERES

Repeating Contractile Functional Units of the skeletal muscle fiber.

Striations

(3 bands / 2 lines / 1 zone)

Z lines

Junction of adjacent sarcomeres

I band

Lighter band with Only Thin Filaments. Changes width on contraction

A band

Dark/dense region containing Thick And Thin Filaments.

Zone of Overlap

Within A band; overlapping thick/thin filaments.

M Line

Center of A band where adjacent thick filaments connect.

H Band

Lighter region on each side of M line with Only Thick Filaments

Transverse tubules (T tubules)

Sarcoplasmic Reticulum

Terminal Cisternae

Triad

TWO TERMINAL CISTERNAE and ONE T TUBULE.

SARCOPLASMIC RETICULUM (SR)

STORES CALCIUM

CALSEQUESTRIN

Protein that binds calcium inside SR.

Calcium concentration surrounding cytosol

40,000 times

F-ACTIN (filamentous)

TWISTED DOUBLE-STRAND of G-actin

​​ Nebulin

Holds two strands of G-actin molecules together.

​Tropomyosin

Double-stranded protein wrapped around F-actin.

Troponin

Protein composed of 3 subunits

Troponin attached to Tropomyosin creates the

Troponin-Tropomysoin Complex

Blocks myosin binding sites

Tropomyosin

Thick Filament

Contain ~ 300 Myosin molecules/filament

Thick filaments have a core of

Titin

Titin connects

Thick filaments to Z lines

Free Head

Forms cross bridge with actin during contraction

Sliding Filament Theory

H AND I BANDS GET SMALLER; ZONES OF OVERLAP GET LARGER.

Action Potentials

plasma membranes that produce and carry electrical impulses

All cells in the body are

Polarized

Inside of cell slightly Negative

compared to outside

MEMBRANE POTENTIAL. \= Electrical Gradient of a Cell

Neurons have Resting Membrane Potentials of about

-70 mV.

Skeletal Muscle Fibers Resting Potentials of about

-85 mV.

Membrane Potential measured in

Millivolts (mV)

Synarthrosis

NO Movement, strongest

Amphiarthrosis

LITTLE Movement

Diarthrosis

FREELY Moveable

Functions of Synovial Fluid

Protection, Lubrication, Nutrient Distribution, and Shock Absorption

Synovial fluid protects the

Articular Cartilage.

Pronation

BACK/POSTERIORLY/DOWNWARD

Supination

ANTERIORLY/UPWARD.

Opposition

Pinching

Inversion

Turning the sole inward.

Eversion

Turning the sole outward.

Protraction

Moving a part of the body ANTERIORLY in the horizontal plane.

Retraction

Moving a part of the body POSTERIORLY in the horizontal plane.

Depression

Moving a body part inferiorly (like opening your jaw).

Elevation

Moving a body part superiorly (as in closing your jaw).

Hip joint

Sturdy ball-and-socket diarthrosis joint

Acetabular Labrum

RIM OF FIBROCARTILAGE

Hip joint articulates between

Head of the Femur and Acetabulum of hip bone.

Biceps Brachii attaches at the

RADIAL TUBEROSITY.

NURSEMAID'S ELBOW

Partial dislocation of the radial head from the Annular Ligament.

Muscles that extend the elbow attach on the

OLECRANON

Knee joint supporting structures

Quadriceps Tendon, Lateral Collateral Ligament, Medial Collateral Ligament, Popliteal Ligaments.

Popliteal Ligaments

Provide posterior support

Medial And Lateral Menisci

Fibrocartilage pads that provide lateral STABILITY

Intracapsular Ligaments

Anterior Cruciate Ligament and Posterior Cruciate Ligament

Normal articular cartilage

Smooth, Thick

Articular cartilage damaged

Rough, bristly collagen fibers on the surface

Damaged articular cartilage increases and promotes

Friction and degeneration

Epimysium -

Dense sheath of collagen fibers around muscle.

Muscle Fascicle -

Bundle of muscle fibers.

Perimysium -

Fibrous layer dividing muscle into compartments.;