Exam 2: Full on review

Joints are:

Connections between bones (aka articulations)

Functions of joints (2):

1.Hold bones together securely2.May allow movement§The more movement a joint allows, the weaker the connection it creates

More Movement:

Weaker connection

Less movement:

Stronger connection

fibrous:(simple)

Immoveableex. cranial sutures, gomphoses(simple)

cartilaginous (simple)

slightly moveableex. pelvic symphysis, spinesimple

synovial: simple

freely moveableex. elbow, wristsimple

Fibrous Joints:

§Immovable§Hold bones together securely§Joints aren’t always about movement

Cartilaginous Joints:

§Semi-moveable§Holds bones together securely but also permit some movement§Strength + Flexibility§Examples:§Intervertebral discs§Pubic symphysis

Synovial Joints:

§Freely moveable§Found at the ends of long bones§Movement must be frictionless

6 anatomical structures common to all synovial joints:

1.Articular cartilage- aka Hyaline cartilage2.Articular capsule3.Joint space4.Synovial membrane5.Synovial fluid6.Reinforcing ligaments- aka Dense regular CT

What type of cartilage is articular cartilage?

The cartilage is known as the HYALINE CARTILAGE

What type of connective tissue makes up reinforcing ligaments?

The DENSE REGULAR CONNECTIVE TISSUE

Bursae:

§flattened fibrous sacs§Lined with synovial membranes§Filled with synovial fluid§Not actually part of the joint§Decrease friction outside the joint during movement

Tendon sheath:

§Elongated bursa that wraps around a tendon§Not actually part of the joint§Decrease friction outside the joint during movement

Arthritis:

§Inflammation of one or more synovial joints§Many causes à acute injury, autoimmune disease, age-related

Osteoarthritis:

§A type of arthritis where articular cartilage wears down§Usually age-related§Hyaline cartilage is replaced with fibrocartilage or bone§Creates painful bone-on-bone contact

CURE FOR “OA”:

The cure for it is known as Joint replacement.Damaged cartilage does not heal well and is not replaced appropriately.but technically no cure

Luxation:

§When articulating surfaces are forced out of their normal position

Subluxation:

Articulating surfaces are in an abnormal position, but this is less severe than a true luxation

Which causes more damage to a joint?

Luxations open up the inside of a joint to damage as well.And a damaged joint, namely damaged articular cartilage, is NEVER going to heal like it should.

“double-jointed”- Flexible:

§Joints are weakly stabilized§Frequent subluxations

Types of synovial joints:

Plane jointsHinge jointspivot jointsball-and-socket:joints

Plane joints:

-gliding or sliding movements.Gliding joints are found between bones of the wrist, ankle, and between your clavicle and superior sternum.

Hinge Joints

angular movmentslike a door hinge allows a door to open and close, hinge joints produce similar, angular movements in one plane.ex.elbow,knee

3.Pivot joints:

Rotational movements:The joint between your skull and spine, your atlanto-occipital joint, is a pivot joint, and you move it when you shake your head “no”.ex.skull/spine

4.Ball and socket joints:

Multidirectional movmentjoints provide the most movement of any joint, and we know that also makes they form the weakest connections between bones.Ball and socket joints include your shoulders and hips which allow for a lot of movement in lots of different planes at once.

2 Types of Movement:

1.Uniaxial = Movement in 1 plane only2.Multiaxial = Movement in 2 or more planes

Uniaxial movements:

§“Up and Down” or “Side to Side”§Movement in one direction that changes the angle between 2 bones

§Flexion:

Movement that decreases the angle of articulating bones

Extension

§Movement that increases the angle of articulating bone

Abduction:

Movement of the limbs away from the body.

Adduction:

Movement of the limbs toward the body

Uniaxial movements – “Circling”:

Movement in one direction that changes the angle between 2 bones

Rotation:

Movement of a joint so that one bone pivots around another

Pronation:

§Movement of the hand so that the hand moves from palm-facing-forward to palm-facing-back

Supination

Movement of the hand so that the hand moves from palm-facing-back to palm-facing-forward

Multiaxial movements:

§Movement in multiple directions that changes the angle between 2 bones§These joints can act slide, move up and down,side to side, and pivot – they can perform the movements of all other joints!

Muscles are responsible:

for all types of body movement

3 Types of Muscle:

1.Skeletal muscle2.Cardiac muscle3.Smooth muscle

Muscle Fascicle:

A bundle of muscle cells observable with the naked eye§The direction of fascicles is the direction of movement!

Muscles can be classified based on fascicle direction: (4 examples)

1.Parallel2.Convergent3.Pennate4.Circular

Parallel Muscles

•Muscle fascicles are parallel to the longitudinal axis•Examples: biceps brachii and rectus abdominis

Convergent Muscles:

•Muscle fascicles form a broad area but come together at a common point•Example: pectoralis major

Pennate Muscles:

•Muscle fascicles form an oblique angle to the tendon of the muscle•Example: extensor digitorum

Circular Muscles:

•Muscle fascicles form concentric rings•Also known as sphincter muscles•Examples: orbicularis oris and orbicularis oculi

Muscles are attached to bone at 2 points:

1.Origin2.Insertion

Origin:

attachment to an immovable or less movable bone

Insertion:

attachment to a movable bone

When muscle contracts?

The insertion moves toward the origin

Body movement occurs?

when muscles contract across joints

Innervation of Muscle:

§A nerve is connected to every muscle cell§This connection is called the neuromuscular junction

Skeletal Muscle:

•Attached to bones via tendons•Cells:•Large•Have multiple nuclei•Striated muscle•Obvious stripes in cytoplasm of cells•Voluntary muscle•The only muscle tissue under conscious control

Cardiac Muscle

•Found only in the walls of the heart•Cells:•Branched•Joined by cap junctions called intercalated discs•Only have one nucleus•Striated muscle•Obvious stripes in cytoplasm of cells•Involuntary muscle•Contractions due to a pacemaker within the heart – NOT the nervous system!

Smooth muscle:

•Found mainly in the walls of hollow visceral organs•Cells:•Spindle-shaped•Only have one nucleus•Arranged into layers – circular and longitudinal•Non-striated muscle•NO obvious stripes in cytoplasm of cells•Involuntary muscleContractions are slow and sustained

Connective Tissue of Muscle:

EpimysiumEndomysiumPerimysium

Epimysium:

§dense tissue that surrounds the entire muscle§Outermost layer

Endomysium:

§dense tissue that surrounds individual muscle cells§Innermost layer

Perimysium:

Dense tissue that sorrounds fascicles

Connective tissue layers extend beyond the muscle and converge to form:

To form tendons!!!

Microscopic anatomy of skeletal muscle:

1.Muscle fibers2.Myofibrils3.Sarcomeres4.Myofilaments•Actin•Myosin5.Regulatory proteins•Topomyosin•Troponin

Myofibrils=

Organelles responsible for the contraction of muscles§ALL muscle cells contain myofibrils§Myofibrils are attached to the plasma membrane at each end of the muscle cell§Myofibrils are surrounded by the sarcoplasmic reticulum§Specialized smooth endoplasmic reticulum in muscle§Stores Calcium

What organelle surrounds each myofibril and what does it release?

§plasma membrane at each end of the muscle cell§Myofibrils are surrounded by the sarcoplasmic reticulumCALCIUM

WHAT DECREASES DURING ATROPHY?

§plasma membrane at each end of the muscle cell§Myofibrils are surrounded by the sarcoplasmic reticulumthat this occurs because the MYOFIBRILS atrophy, or go away, not the muscle cells themselves.As the cell becomes less tightly packed with myofibrils, it gets smaller and narrower.The result is an overall slimmer muscle.

Sarcomeres:

Repeating units that make up myofibrils

Myofilaments:

Repeating units that make up myofibrils

MYOSIN:

THICK FILLAMENT

ACTIN:

THIN FILLAMENT

M LINE=

MIDDLE OF THE SARCOMERE

Z-LINE:

END OF THE SARCOMERE

THICK AND THIN FILAMENTS OVERLAP:

IN THE ZONE OF OVERLAP

§Muscle Contraction:

1.An electrical impulse travels from the brain to a nerve2.Acetylcholine, a neurotransmitter, is released from the end of the nerve at the neuromuscular junction3.Acetylcholine travels into the muscle and causes the sarcoplasmic reticulum to release its stored calcium ions

MUSCLE CONTRACTION:(CONTINUED)

4.Calcium ions bind to troponin on the sarcomere5.This binding action causes a rotation of the tropomyosin4.This exposes the active sites on the actin6.Myosin heads can now bind to the active sites on actin

Muscle contraction: Information

7.The cross-bridges form, and myosin pulls the actin8.As the actin myofilaments are pulled, the sarcomere (and the entire muscle) become shorter9.The result is a contraction

Actin (info)

§Has an active site, or binding site§Myosin cross-bridges form when myosin binds to the active sites on actin

Regulatory protein of Actin:

TropomyosinTroponin

Tropomyosin: (function)

§: A protein that covers the bindingsites when the muscle is relaxed§This prevents actin and myosin binding, preventing contraction

Troponin: (function)

§A protein that controls the movement of tropomyosin§Moves in response to calcium

MICROSCOPIC ANATOMY:

1)Nerve releases ACh2)ACh binds to cell3)ACh causes calcium to be released into cytoplasm4)Calcium changes the shape of the sarcomere5)Contraction occurs

•3 Pathways to make ATP

Direct phosphorylationAerobic PathwayAnaerobic glycolysis and lactic acid formation

Direct Phosphorylation:

Creatine phosphateCoupled reaction of creatine    phosphate (CP) and ADPWe phosphorylate, or add a phosphate, to ADP so it becomes ATP.So instead of having 2 phosphates, we give it a 3rd.Creatine phosphate will give a phosphorous molecule to ADP so that it can become usable ATP.

Aerobic respiration:

•Uses O2 and glucose to generate ATP•Glucose is broken down to CO2 and water, releasing energy (about 32 ATP)•This is a slower reaction that requires continuous delivery of oxygen and nutrients

Anaerobic glycolysis and lactic acid formation:

•Reaction that breaks down glucose withoutO2•Glucose is broken down to lactic acid to produce 2 ATP•Lactic acid causes muscle soreness•This reaction is not as efficient, but it is fast

Joints are:

Connections between bones (aka articulations)

Functions of joints (2):

1.Hold bones together securely2.May allow movement§The more movement a joint allows, the weaker the connection it creates

More Movement:

Weaker connection

Less movement:

Stronger connection

fibrous:(simple)

Immoveableex. cranial sutures, gomphoses(simple)

cartilaginous (simple)

slightly moveableex. pelvic symphysis, spinesimple

synovial: simple

freely moveableex. elbow, wristsimple

Fibrous Joints:

§Immovable§Hold bones together securely§Joints aren’t always about movement

Cartilaginous Joints:

§Semi-moveable§Holds bones together securely but also permit some movement§Strength + Flexibility§Examples:§Intervertebral discs§Pubic symphysis

Synovial Joints:

§Freely moveable§Found at the ends of long bones§Movement must be frictionless

6 anatomical structures common to all synovial joints:

1.Articular cartilage- aka Hyaline cartilage2.Articular capsule3.Joint space4.Synovial membrane5.Synovial fluid6.Reinforcing ligaments- aka Dense regular CT

What type of cartilage is articular cartilage?

The cartilage is known as the HYALINE CARTILAGE

What type of connective tissue makes up reinforcing ligaments?

The DENSE REGULAR CONNECTIVE TISSUE

Bursae:

§flattened fibrous sacs§Lined with synovial membranes§Filled with synovial fluid§Not actually part of the joint§Decrease friction outside the joint during movement

Tendon sheath:

§Elongated bursa that wraps around a tendon§Not actually part of the joint§Decrease friction outside the joint during movement

Arthritis:

§Inflammation of one or more synovial joints§Many causes à acute injury, autoimmune disease, age-related

Osteoarthritis:

§A type of arthritis where articular cartilage wears down§Usually age-related§Hyaline cartilage is replaced with fibrocartilage or bone§Creates painful bone-on-bone contact