Joints and microscopic anatomy of bone

What’s another name for joints?

Articulations

3 types of Joint Types

Fibrous, Cartilaginous, and Synovial

What makes a synovial joint synovial?

It has to have articular cartilage, capsule (enclose the joint), reinforcing ligaments.

6 synovial Joints

Ball + Socket, gliding/plane, pivot, saddle, condyloid, and hinge

Ball and Socket

Femoral Head and Acetabulum

gliding/plane

between inter-carpals, inter-carpals, and the common vertebrae

Pivot

Atlas/axis and radius on ulna

Saddle

Clavicle + Sternum, between trapezium and 1st metacarpal

Condyloid

Metacarpals to proximal phalange, radius to Scaphoid, and occipital to atlas

Hinge

Elbow, knee, interphalangeal, tibia to talus

Fibrous

Sutures and teeth

Cartilaginous

Vertebrae

Synovial

All movable

3 types of cartilage

Hyaline, elastic, and fibocartilage

Hyaline

Ribs, synovial joints, trachea, and nose

Elastic

Ear lobes and epiglottis

Fibocartilage

Knee, vertebrae, pubis

Embryonic Skeleton

Mostly made out of cartilage (hylaine) and slowly replaced by bone through a process called endochondral ossification.

epiphyseal line

Growth plate

2 types of bone material

Compact and Spongy bone

Compact

dense and strong, typically found in diaphysis

Spongy Bone

(cancellous) porous, and weaker - found in ephysis

Red Marrow

found in the epiphysis - it makes red blood cells (but makes all 3 blood cell types)

Yellow Marrow

In core diaphysis - often associated with immune cell formation

Osteoblasts

Bone builders, cells that deposit new bone material, and takes materials like calcium from the blood and put it into the bone

Osteoclasts

Breaks down bone and putting it into the blood stream

Adults

Have a balance between oblast and oclast function

Juveniles

oblast > oclast

Elderly (esp. post-menopause)

oclast > oblast

Wolff’s Law

Weight-bearing exercise simulates oblasts

Strong Bones

Vitamin D helps absorption of calcium (sunlight)

estrogen (linked directly)

To oblast function and more estrogen equals more oblast activity

4 Stages of Bone Fracture Repair

Hematoma, Soft Callus, Hard Callus, and remodeling

Hemoato

First Phase, white blood cells prevents the risks of infection

Soft Calus

Phase 2, cartilage builders form soft callus and acts as a temporary bridge

Hard Calus

Phase 3. osteoblasts is added between the fracture building the extra tissue

Remodeling

Phase 4, sends osteoblasts to break down extra tissues for the bones

Hyperparathyroidism

overactive parathyroid gland

Pagets

Accelerated turnover of bone material

Rickets

Less/no vitamin D

Craniosynostosis

Premature fusing of skull

Scoliosis

Sideways curvature of the spine

Rheumatoid Arthritis

Autoimmune Joints

Bursitis

Inflammation of bursae sac

Osteoarthritis

Bone on bone, due to cartilage wearing down

Osteogenesis imperfecta

Imperfect growing of bone, brittle bone disease

Leukemia

Cancer of bone marrow

Klippel-Feil Syndrome

Fusion of cervical vertebrae

Fibrous Dysplasia

Bone salt replaced by fibrous scar-like tissue

What regulates the calcium in your body?

Parathyroid hormone (PTH)

What are the three hormones that regulate calcium?

Parathyroid Hormone (PTH), Vitamin D, and Calcitonin