Muscle System and Joints Review

These flashcards cover key concepts related to muscles, joints, and their functions in the human body.

What are the main functions of joints?

Hold bones of the skeleton together and give the skin mobility.

What are the three structural classifications of joints?

Fibrous, Cartilaginous, and Synovial.

What is a sprain?

when the LIGAMENTS of a joint are stretched or torn.

What distinguishes rheumatoid arthritis from osteoarthritis?

Rheumatoid arthritis is an autoimmune disease attacking body tissues, while osteoarthritis is caused by wear and tear on joints.

What are the main types of muscle tissue?

Skeletal muscle, Cardiac muscle, and Smooth muscle.

What is the primary function of the sarcoplasmic reticulum in muscle fibers?

To regulate intracellular levels of calcium.

What is the sliding filament theory?

The theory explaining muscle contraction as the sliding of actin over myosin filaments.

What is the role of myoglobin in muscle fibers?

Myoglobin stores oxygen in muscle tissue.

What are prime movers or agonists?

Muscles that provide the major force for producing a specific movement.

How is muscle tension developed during contraction?

By the interaction of actin and myosin filaments within sarcomeres.

What happens during the latent period of muscle contraction?

There is a delay where muscle tension begins but is not yet measurable.

What type of joint movement is abduction?

Abduction is the movement of a limb away from the midline of the body.

What is the significance of having slow and fast muscle fiber types?

Slow oxidative fibers are used for endurance, while fast glycolytic fibers are used for short bursts of power.

What defines isotonic and isometric contractions?

Isotonic contractions involve movement with tension overcoming the load; isometric contractions involve tension without movement.

What muscles are involved in plantar flexion?

Gastrocnemius and soleus.

What is muscle recruitment?

Recruitment occurs when a stimulus exceeds what one motor unit can handle, requiring additional motor units.

What are the three functional Joint classifications?

synarthroses, amphiarthroses, and diarthroses

synarthroses

“Immovable” Joints

amphiarthroses

“Slightly Movable” Joints

diarthroses

“Freely Movable" Joints

Sutures

Found connecting bones of skull (IMMOVABLE)

Syndesmoses

Type of joint where bones are connected by ligaments, allowing for slight movement.

Gomphoses

Type of joint where a peg fits into a socket, such as in the connection of teeth to their sockets in the jaw.

What are the fibrous Joints?

Sutures, Syndesmoses, and Gomphoses

What are the Cartilaginous Joints?

Synchondroses and symphyses

Synchondroses

Immovable Joints that’s a bar or plate of cartilage that join two bones together ( Epiphyseal plate)

Symphyses

Fibrocartilage sandwiched between articular cartilage and held together by a ligament. (Slightly movable: found in Vertebrae)

Synovial joint Structure:

• Bone ends are covered in articular cartilage

• Space between the bones is the cavity

• Articular capsule: Hold the joint together

  -contains: 1. Ligament 2. Synovial membrane (synovial fluid)

What is Bursa?

Individual sacs of synovial tissue

Muscles attach to bone to provide what?

movement

What is the origin?

The place of attachment which has little to no movement

What is the insertion?

The place of attachment which has the most movement (Moveable bone)

Gliding

a type of joint movement allowing bones to slide past one another.

What bones have gliding movement?

Carpals of the wrist and Tarsals of the foot

What is an angular movement?

Increasing or decreasing the angle between two bones

What are the types of angular movement?

Flexion, extension, abduction, adduction, and circumduction.

What is flexion?

REDUCING the angle between bones

What is extension?

INCREASING the angle between bones.

What is hyperextension?

When the extension goes BEYOND the normal upright position

Flexion of the foot

Can point UP towards the body (Dorsiflexion)

or

can Point DOWN from the body (Plantar Flexion)

Abduction

Movement of the limb away from the midline of the body

Adduction

Movement of the limb towards the midline of the body.

Circumduction

Moving the distal portion of a limb in a circular direction

Rotation

The turning of a bone around its long axis

What are the special movements that refer to the movement of the Radius around the Ulna?

Supination and Pronation

What is Supination?

Turning backward

What is Pronation?

Turning forward

What are the special movements that refer to the movement of the foot?

Inversion and Eversion

What is inversion?

The sole of the foot faces medially

What is Eversion?

The sole of the foot faces laterally

Protraction and Retraction

Movements that involve the anterior and posterior displacement of the scapula or jaw.

Elevation and Depression

Movements that increase or decrease the angle between the body parts, such as lifting the shoulders or lowering the jaw.

What is opposition?

an action that occurs when the thumb moves to touch the tips of other digits

Types of freely moveable joints

Gliding/ Planar, Hinge Joints, Condyloid Joints, Saddle Joints, Pivot Joints, and Ball-and-Socket

Gliding/ Planar joint

Carpal bones of wrist and Tarsal bones of ankle

Hinge Joints

Knee and Elbow

Condyloid Joints

Metatarsals, Metacarpals, and Phalanges

Saddle Joints

Thumb (Metacarpal and Trapezium)

Pivot Joints

Atlas and Axis or Radius and Ulna

Ball & Socket Joints

Shoulder and Hip

What is a strain?

The TENDON of a joint are stretched or torn

Can your directly sprain/strain a ligament or tendon

NO

Dislocations

When bones are forced out of alignment

Subluxation

A partial dislocation of a joint

Bursitis and Tendonitis

inflammation of the bursae or tendons, often caused by repetitive motion or overuse.

What is arthritis?

Inflammatory or degenerative disease which damages the joints

Who had SirenMelia (Mermaid Syndrome)

(Shiloh Pepin) It is a rare congenital condition where a person is born with fused legs resembling a mermaid’s tail. It affects limb development and can also involve other organ systems.

Osteoarthritis

Wear and tear of articular cartilage in the joints which lack the ability to be replaced

common: The elderly

Drug: Capacsin (From peppers)

Rheumatoid Arthritis

Caused by an autoimmune disease that attacks the body’s tissue causing joints to shorten and stiffen

common: 40-50

Gouty Arthritis

When excessive Uric acid is deposited in the joints forming crystals (an inflammatory response -usually starts in big toe)

Skeletal Muscle

A type of muscle tissue under voluntary control and attached to bones, enabling locomotion and movement.

Characteristics: displays light and dark bands appearing as stripes and striations

Cardiac Muscle

A type of involuntary muscle tissue found only in the heart, responsible for pumping blood throughout the body.

Characteristics: Contains Striations

Smooth muscle

A type of involuntary muscle tissue found in the walls of hollow organs, responsible for various functions such as digestion and blood vessel regulation.

Characteristics: No striations and operates involuntarily, helping in processes like peristalsis and maintaining blood pressure

Functions of Skeletal muscle

Movement of Skeleton, Maintain posture, stabilize joints, and generate heat

Functions of Smooth muscle

Excitability, contractibility, extensibility, and elastibility

What are the (smaller) functional units of Skeletal muscle?

Muscle(a bundle of muscle fascicles), Fascicle(Bundle of muscle fibers), and Muscle Fiber(the muscle cell)

Types of smooth muscle

Longitudal, and circular muscle

Peristalsis

Alternating contraction and relaxation of opposing muscles

Varicosities

The nerves that innervate smooth muscles

Connective Tissue Sheath

A layer of connective tissue surrounding and supporting muscle fibers, providing structure and facilitating movement.

What’s the Endomysium

“Within” the muscle: A sheath of primary reticular fibers that covers the muscle fiber

What’s the perimysium?

“Around” the muscle: A sheath of fibrous connective tissue that covers the muscle fascicle

What’s the Epimysium?

“Outside” of the muscle: A sheath of dense irregular connective tissue that covers the whole muscle

Direct or fleshy attachments

The epimysium fuses to the periosteum of a bone or perichondrium of a cartilage

Indirect attachments

The connective tissue wrappings of the muscle extend beyond the muscle to form either a rope like tendon or sheet like aponeurosis

Muscle Fiber

Sarcolemma

Cell membrane of the muscle cell

Sarcoplasm

Cytoplasm of the muscle cell

Myoglobin

Red pigment that stores oxygen in the muscle

Myofibrils

Rod-like fibers that run parallel down the length of the muscle fiber

_______- thousands of these myofibrils can be found in one fiber and can account for 80% of cellular volume

hundredths

Myofibrils

Primarily made of thick and thin filaments

What are Myofibrils composed?

Protein called myosin

Myosin Heads

Globular heads on Myosin that can attach to actin

What are thin filaments primarily composed of?

actin

Tropomyosin

A thin strand that wraps around actin (thin) and blocks the actin sites

Tropopinin

A three polypeptide complex that regulates the position of tropomyosin relative to the actin binding sites

Sarcoplasmic Reticulum

An elaborate smooth endoplasmic reticulum that’s primary function is to regulate intercellular levels of calcium

T Tubules

A long tube-like structure that is continuous with the sarcolemma and runs in between 2 sarcoplasmic reticulums

Purpose: initiate the release of calcium from the sarcoplasmic reticulum

Muscle Contraction

Shortening of muscle fibers by the activation and movement of actin fibers over myosin fibers causing overlap