gg way lec 12!!

A joint allows no movement despite joining two bones. What determines its mobility?

The structure of the junction holding the bones together.

When classifying a joint by movement rather than connective material, which classification is being used?

Functional classification.

Bones are joined by dense fibrous connective tissue without a synovial cavity. What structural joint class is this?

Fibrous joint.

Bones are joined directly by cartilage rather than a synovial cavity. What structural joint class is this?

Cartilaginous joint.

A joint has a cavity between its articulating bones and is supported by ligaments. What structural class is it?

Synovial joint.

What functional classification applies to every synovial joint?

Diarthrosis, or freely movable joint.

What functional class describes a skull suture joined by short, tight fibers?

Synarthrosis, or immovable joint.

A tooth root fits into its alveolar socket. Which fibrous joint subtype is present?

Gomphosis.

An epiphyseal growth plate unites bones through hyaline cartilage. What type of joint is it?

Synchondrosis.

What bony joint results when an epiphyseal plate is replaced by bone?

Synostosis.

A joint connects the distal tibia and fibula by relatively long fibrous tissue. What subtype is it?

Syndesmosis.

An interosseous membrane joins neighboring bones using what type of tissue arrangement?

A sheet of fibrous connective tissue.

Adjacent vertebral bodies are united by a fibrocartilage disc. Which cartilaginous joint subtype is this?

Symphysis.

A symphysis typically belongs to which functional mobility class?

Amphiarthrosis, or slightly movable joint.

What movement results from wave-like contractions of smooth muscle in the walls of a digestive tube?

Peristalsis propels contents along the tube.

According to the bipedalism comparison in the lecture, human walking used approximately how much less oxygen than chimp locomotion?

75% less oxygen.

What skeletal changes were linked to improved energy efficiency in upright walking?

Longer leg bones and an outward-tilted pelvis.

Which cavity distinguishes a freely movable synovial joint from fibrous and cartilaginous joints?

Synovial or joint cavity.

The ends of bones in a synovial joint are covered by what kind of cartilage?

Hyaline articular cartilage.

Which layer of the articular capsule may contain ligaments and provides outer support?

Outer fibrous membrane.

Which articular capsule layer secretes the joint's lubricating fluid?

Inner synovial membrane.

Why must synovial fluid carry nutrients to articular cartilage?

Articular cartilage is avascular and lacks blood vessels.

What happens to healthy synovial fluid viscosity under high shear, such as rapid running?

It decreases; the fluid is shear-thinning or pseudoplastic.

How does healthy synovial fluid help protect joints during sudden impact?

It acts as an elastic shock absorber.

Why does repeated joint motion improve nutrient delivery to cartilage?

Movement pumps nutrient-bearing synovial fluid by convection.

If synovial fluid becomes abnormally thin and watery, which protective action is impaired?

Lubrication of the joint surfaces.

A synovial-fluid-filled sac cushions structures and reduces joint friction. Which accessory structure is involved?

Bursa.

A damaged knee pad lies between opposing bone surfaces and consists of fibrocartilage. What is it?

Meniscus or articular disc.

What accessory structures cushion and protect articular cartilage using adipose tissue?

Fat pads.

Which joint stabilizers prevent extreme movements that could damage a diarthrosis?

Accessory ligaments.

If a fibrous cord attaches a muscle to a bone near a joint, what structure is it?

Tendon.

Which hormone from the ovaries and placenta relaxes the pubic symphysis during birth?

Relaxin.

A surgeon examines and repairs the inside of a joint through minimal incisions. What procedure is used?

Arthroscopy.

A damaged hip joint is surgically replaced. What procedure is this?

Arthroplasty.

Which type of arthritis results from autoimmune attack on the synovial membrane?

Rheumatoid arthritis.

Activated white blood cells transform the synovial lining into inflamed, enlarged tissue. What is this tissue called?

Pannus.

Which enzymes released during rheumatoid synovial inflammation degrade cartilage and connective tissue?

Metalloproteases.

A weight-bearing joint loses articular cartilage with relatively little inflammation. Which disease fits best?

Osteoarthritis.

Which bony growths commonly accompany cartilage degeneration in osteoarthritis?

Bone spurs.

A painful joint contains deposits of sodium urate crystals in its soft tissues. What disease is responsible?

Gouty arthritis.

How can kidney dysfunction contribute to gouty arthritis?

Failure to excrete enough uric acid raises its concentration.

What can happen to an affected joint when gouty arthritis progresses untreated, according to the notes?

The bones may fuse and the joint becomes immobile.

A patient develops arthritis after an illness transmitted by deer ticks. Which disease is suggested?

Lyme disease.

An inflamed synovial-fluid sac near a joint causes localized pain. What condition is this?

Bursitis.

Which disease inflames joints between vertebrae and between the sacrum and hipbone?

Ankylosing spondylitis.

In congenital hip dislocation, what position does the femoral head occupy?

Outside the acetabulum.

Which intervertebral-disc structure forms the semifluid central core?

Nucleus pulposus.

Which intervertebral-disc component encloses the nucleus with multiple fibrous layers?

Annulus fibrosus.

What happens to water in the nucleus pulposus when external compression increases?

Water is squeezed out and removed by vertebral capillaries.

What happens to nucleus pulposus hydration while lying down without compressive pressure?

Water returns to the nucleus as pressure decreases.

How does cyclic compression and unloading help sustain an intervertebral disc?

It pumps nutrients inward and metabolic wastes outward.

At approximately what age do the lecture notes say nucleus proteoglycan changes and water loss gradually begin?

About 30 years of age.

How can age-related loss of nucleus water promote disc damage?

Increased loading can separate annulus layers and create radial fissures.

Why can a posterolateral herniated disc cause marked pain?

Protruding nucleus material can impinge on a spinal nerve root.

In the lecture, TENS treatment is described as increasing production of what pain-modulating substances?

Endorphins.

Severe loss of hip articular cartilage eventually causes what painful contact?

Raw bone articulating against raw bone.

What long-term complication is emphasized after hip-joint replacement?

Loosening of prosthetic components.

An ACL graft is taken from the patient's own body. What is this graft category?

Autograft.

The ACL reconstruction technique using the patellar ligament harvests which portion of that ligament?

The middle third.

Which two hamstring tendons are looped to reconstruct the ACL in the notes?

Semitendinosus and gracilis.

An ACL replacement uses a donated Achilles tendon. What graft category is used?

Allograft.

By inhibiting which chemical products do NSAIDs such as aspirin reduce inflammation?

Prostaglandins.

What cellular activity do corticosteroid anti-inflammatory drugs depress?

White blood cell activity.

How can a gout medication lower elevated blood uric acid without blocking its production?

By increasing urinary uric acid excretion.

Which class of drugs reduces immune activity to slow autoimmune joint destruction?

Immunosuppressants.

Which energy conversion directly underlies muscular force production?

Chemical energy from ATP becomes mechanical energy.

According to Lecture 12, contracting skeletal muscles can generate as much as what proportion of body heat?

85%.

A muscle cell reacts to a neurotransmitter by generating an action potential. Which functional property is demonstrated?

Excitability.

A muscle-cell action potential spreads along the plasma membrane. Which property is demonstrated?

Conductivity.

A muscle cell shortens and thickens to generate force. Which property is demonstrated?

Contractility.

A muscle is stretched without sustaining tissue damage. Which property is demonstrated?

Extensibility.

A muscle returns to its original shape after being stretched. Which property is demonstrated?

Elasticity.

Which intercalated-disc connections allow action potentials to spread between cardiac muscle cells?

Gap junctions.

Which intercalated-disc structures give cardiac muscle cells strong mechanical attachment?

Desmosomes.

What property lets cardiac pacemaker cells spontaneously generate action potentials?

Autorhythmicity.

Which cardiac structures are specifically named as components of the intrinsic pacemaker system?

SA node, AV node, and Purkinje fibers.

What lets intestinal smooth muscle cells contract together as one functional unit?

Gap junctions between the cells.

Why can smooth muscle cells in the iris contract individually rather than as one unit?

They lack the gap junctions described for intestinal smooth muscle.

A tissue consists of nonstriated spindle-shaped cells with single central nuclei. Which muscle type is it?

Smooth muscle.