Bio 103 Skeletal, joint, and muscular system

Skeletal, joint, and muscular system

Skeletal system =

Axial (80) and Appendicular (126)

Is there a difference between appendicular and axial bones?:

Appendicular bones enable movement, while the axial bones are more for protection, structure and support

The skeletal system is comprised of:

Bones, joints, and supporting tissues (Ligaments, tendons, and cartilage) 

The main tissues found in bones are:

osseous tissue, dense regular connective tissue (in ligaments and tendons), dense irregular connective tissue (in periosteum), and bone marrow.

What is the function of bones?:

Mineral storage, fat storage, production of blood cells, maintain pH, protection and movement

Function of Long bones?:

movement, mineral storage, and blood cell production

Function of Short bones?:

Stability and support

Function of Sesamoid bones?:

Protects tendons and reduces friction

Sesamoid are found in:

All joints

The structure of bone is:

periosteum, perforating fibers, diaphysis, epiphysis, articular cartilage, marrow cavity, and endosteum.

Periosteum is:

A thin, tough outer layer covering the bone.

Perforating fibers:

Fibers that attach the periosteum to the bone.

Diaphysis:

The middle, long part of a bone.

Epiphysis:

The rounded ends of a bone.

Articular cartilage:

Smooth tissue covering bone ends at joints.

Marrow cavity:

The hollow space inside the bone holding marrow.

Endosteum:

 A thin layer lining the inside of the bone.

Bone structure - compact bone vs spongy bone:

Compact Bone: Dense, hard outer layer of bone that provides strength and support.

Spongy Bone: Lighter, porous inner layer of bone that absorbs shock and houses bone marrow.

What are episeal lines?:

are remnants of the growth plates

What are epiphyseal plates?:

 Are growth plates

What is the structure of short and flat, irregular, and sesamoid bones?:

Covered in periosteum, diploe, and sinuses

*Why do some people need a bone marrow transplant?:

Healthy blood cells aren’t being produced enough

*What kind of complications can occur from a bone marrow transplantation?:

Infection and rejection

Extracellular matrix of bone:

Inorganic matrix (65% consisting of minerals)

Organic matrix (35% collagen fibers, osteoids, and usual ECM)

Why is calcium important for bones?:

It creates strength and hardness

Why are hydroxide salts important for the bones?:

they form hydroxyapatite, the mineral that makes bones strong and rigid.

The bone cells are:

Osteoclasts, osteoblasts, osteocytes, and osteogenic cells (stem cells that differentiate into osteoblasts) 

Function of osteoclasts?:

Reabsorb bone, secretion of acid and enzymes

Function of osteoblasts?:

Bone deposition/bone creation

What are osteocytes?:

 Mature cells in lacunae/retirement cells

Function of osteogenic cells?:

Differentiate into osteoblasts

Is lacunae a cavity?:

Yes

How do osteoclasts remove old or damaged bone?:

They use acid to remove inorganic matter, which allows enzymes to break down the bone

What is the structure of compact bone?:

Lamellae, central canal, lacunae, and canaliculi

Trabeculae:

Boney struts (designed to resist compact stress)

Trabeculae is found in which type of bone?:

Spongy bone

Define osteogenesis:

 The formation of bone cells

Define ossification:

the formation of bone from cartilage

When and where does ossification begin?:

 During embryonic period and continuous throughout adulthood. They begin in ossification centers

Explain the relationship between endochondral ossification and cartilage template:

Endochondral ossification is the process where bone forms from a cartilage template

Is endochondral ossification the most common form of bone formation?:

Yes

How does growth hormone work?:

secreted by the pituitary gland and communicates cell growth

What role does testosterone play in bone growth?:

Increases appositional growth, and increases the rate of mitosis

What role does estrogen play in bone growth?:

 Inhibits osteoclasts, and accelerates closure of epiphyseal plate

*How does gigantism and acromegaly happen?:

caused by an overproduction of growth hormone, due to a pituitary gland tumor.

*What kinds of issues can occur from gigantism/acromegaly?:

Organ Enlargement, nerve compression, and cardiovascular problems

*What causes osteoporosis?:

Bones become weak and brittle due to loss of bone density

*And what kinds of issues can occur from osteoporosis?:

Fractures, pain and mobility loss

*How to prevent osteoporosis?:

Lifestyle changes, supplements, and medication

Explain what bone remodeling is:

Old bone being replaced with new bone

Is old bone removed using bone reabsorption?:

Yes

Calcium ions replace:

 old and brittle bone with new bone

What role does parathyroid hormone play in blood calcium levels?:

PTH signals bones to release calcium into the bloodstream.

An increase in osteoblast activity and a decreased activity in osteoclasts results in:

Increased bone deposition

An increase in osteoclast activity and a decreased activity of osteoblasts results in:

Decreased bone deposition

Simple fracture vs Compound fracture:

Simple bone fracture does not pierce the skin, and a compound fracture protrudes out of the skin (ouch)

What is an epiphyseal plate fracture?:

Break in growth plate

What is a compression fracture?:

 Breaking of cartilage

What is the definition of articulation?:

 Where bones meet

What do articulations do?:

Allow movement, provide stability, and allow long bones to lengthen

What are the functional classifications based in motion?:

Synarthrosis, amphiarthrosis, and diarthrosis

What is synarthrosis?:

joint that is immovable

What is amphiarthrosis?:

joint that allows limited movement

What is diarthrosis?:

joint that allows free movement

Dense regular collagenous CT is both:

Synarthrotic and amphiarthrotic

Structural classification of dense regular collagenous tissue:

fibrous joints, cartilaginous joints, and synovial joints

Cartilaginous joints perform what type of movement?:

synarthrotic and amphiarthrotic 

What do synovial joints do?:

Allow plenty of movement and flexibility

What are the 3 types of fibrous joints?:

suture, gomphosis, and syndesmosis

What are the 2 types of cartilaginous joints:

Synchondrosis and symphysis

What is the function of synchondrosis?:

 Stability and connect bones with hyaline cartilage

What is the function of symphysis?:

Slight movement and cushioning between bones. Found in vertebrae and the pubic bone

Where is cartilaginous tissue found?:

The ear, nose, trachea, intervertebral discs, and growth plates.

Articular Capsule:

 Encloses and stabilizes the joint

Articular Cartilage:

Cushions and protects bone ends, reducing friction

Joint Cavity:

Contains synovial fluid, allowing for smooth, frictionless movement

Diarthrosis:

Refers to synovial joints that allow free movement, facilitating complex motion

What is the function of ligaments?:

 Attach bone to bone

What is the function of function tendons?:

Attach muscle to bone

What is the function of bursae tendon sheaths?:

Reduce friction

*What is bursitis?:

Inflammation of a bursa, usually caused by repetitive movement, pressure, or injury.

What are the two types of synovial joints you are supposed to focus on?:

Plane joint (gliding joint) and hinge joint

What does a plane/gliding joint do?:

gliding movements between flat bone surfaces.

What does a hinge joint do?:

flexion and extension (like a knee or elbow)

What does uniaxial mean?:

One direction

What is a specific plane/gliding joint?:

Spine

Skeletal muscle does not only contain muscle cells, it also contains:

Nerves and blood vessels

Explain endomysium:

A thin layer of connective tissue that surrounds each individual muscle fiber, providing structural support and insulating the fiber.

Explain fascicles:

Bundles of muscle fibers grouped together within a muscle, each surrounded by perimysium.

Explain perimysium:

A sheath of connective tissue that encases each fascicle, protecting and allowing nerve and blood vessel passage

Explain epimysium:

 The outermost layer of connective tissue that wraps the entire muscle, providing protection and structural integrity.

 

Muscle cells are also referred to as:

Muscle fiber and a myocyte

What is a diaphragm?:

A large muscle found in the lower region of the lungs, it aids in coughing, vomiting and expelling waste

Sphincters are muscles found in the:

digestive tract

What are the muscle roles in movement? 4 Types:

Agonist (prime mover), antagonist, synergist, and fixator

Antagonist:

The muscle that opposes the action of the agonist, allowing for controlled movement and balance.

Synergist:

A muscle that assists the agonist/prime mover by adding extra force or reducing unnecessary movement.

Fixator:

A muscle that stabilizes the origin of the agonist/prime mover, helping to anchor the joint and provide a stable base for movement.

What is a muscle insertion?:

 what moves away

What is a muscle origin?:

what remains stable