ANTHR 390 Midterm Prep

Primary functions of the skeleton

Support and protect soft tissue, movement, blood cell production, mineral storage, fat storage

Connective tissues

A class of tissues made up of cells and a surrounding and supporting matrix

Periosteum

Connective tissue covering the outer surface of the bone, bound to bone by Sharpay’s fibres, outer fibrous layer for strength, inner osteogenic layer houses bone cells

Endosteum

Connective tissue lining the medullary cavity, also covers the trabeculae of cancellous bone, similar to inner osteogenic layer of periosteum, lack fibrous layer and is very fragile

Red marrow

Includes blood cells and blood cell precursers, supporting matrix is fragile

At birth all marrow is

Red

Yellow marrow

Largely made of adipose tissue, network of supportive tissues, lipid storage cells, can convert to red marrow if necessary

Cartilage

Connective tissue composed of matrix and cells that deposit and maintain

Hyaline cartilage

Ground substance and type 2 collagen fibres, chondrocytes in lacunae in matrix, covers most joint surfaces, makes up costal cartilages, many developing bones start this way

Fibrocartilage

Most of matrix is dense parallel bundles of type 1 collagen fibres, islands of cells surrounded by small amounts of matrix more similar to hyaline cartilage sit between large bundles, found in pubic symphysis, intervertebral discs, and menisci of knee

Fibrous joints

Bones joined directly by fibrous tissue

Cartilaginous joints

Bones are joined by cartilage

Symphysis

Subtype of cartilaginous joint, bones capped with hyaline cartilage and joined by fibrocartilage

Synovial joints

Highly mobile, bone surfaces coated by hyaline cartilage, synovial membranes surround joint cavity and secrete synovial fluid, joint capsule binds the joint together, ligaments guide and restrict movement

Collagen

Main structural protein

Type 1 collagen

Most abundant, about 90% of collagen, most collagen in dentine and fibrocartilage, rod like relatively rigid molecule made of 3 amino acid chains in triple helix, rich in hydroxyproline

Hydroxyapatite

Crystals of mineral are packed in an around the collagen fibres, deposited after fibrils are formed, provides strength and rigidity

Osteoblasts

Secrete osteoid, lay bone down

Osteoclasts

Resorb bone matrix by dissolving mineral portion and consuming protein portion

Osteocytes

Maintain bone matrix, originate as osteoblasts

How do osteocytes communicate

They occupy lacunae in amtrix with tunnels (canaliculi) connecting them, which processes (filopodia) run through so osteocytes can communicate

Osteoprogenitor cells

Stem cells important to bone growth and repair, found in endosteum and osteogenic layer of periosteum, very active in juveniles, can differentiate into osteoblasts or chondroblasts when needed

Woven bone

Immature bone, deposited rapidly, collagen fibres show random orientation, osteocytes arranged in irregular pattern

Lamellar bone

Well organized parallel layers, osteocytes spaced in between, regular arrangement provides strength

Cancellous bone

Trabeculae of bone surround spaces filled with red or yellow marrow, trabecular surfaces are lined with endosteum, osteocytes occupy lacunae within trabeculae, other bone cells are found on trabecular surfaces

Compact bone

Cortical or Haversian, longitudinal Haversian canal holds blood vessels, canal is surrounded by lamellae of bone, Bolkmann’s canals link Haversian canals, osteocytes sit in lacunae between lamellae, intersititial lamellae between osteons, circonferontial lamellae at periosteal surface

Shoulder

Only bony link between the arm and the rest of the skeleton is via the clavicle, functions as a strut holding arm out from torso and transferring weight from arm to torso, wide range of motion

Rotator cuff

Subscapularis, supraspinatus, infraspinatus, function to stabilize shoulder and move

Subscapularis

Arises from subscapular fossa

Supraspinatus

Arises from supraspinous fossa

Infraspinatus

Arises from infraspinous fossa

Muscles of the shoulder

Deltoideus and pectoralis

Deltoideus

Runs from clavicle and scapula to deltoid tuberosity on humeral shaft, abducts arm at the shoulder

Pectoralis major

Runs from anterior surface of clavicle, sternum, and costal cartilages of upper rubs to lateral groove of humerus, flexes and adduct humerus

Muscles of the elbow

Biceps brachii, triceps brachii, brachialis

Biceps brachii

Two heads, tendon of long head arises from supraglenoid tubercle of scapula and passes through bicipital sulcus of humerus

Triceps brachii

Three heads, long head runs from infraglenoid tubercle of scapula, other heads from humeral shaft, common insertion on olecranon of ulna

Brachialis

Originates from shaft of humerus, inserts on brachial tuberosity of ulna, flexes even when forearm is pronated

Anterior compartment

Houses muscles arising from medial epicondyle of humerus and anterior aspect of ulnar and radial shafts, flexes wrist and digits

Posterior compartment

Houses muscles arising from lateral epicondyle of the humerus and posterior aspect of ulnar and radial shafts, extend wrist and digits

Flexor retinaculum

Band of ligament from scaphoid and trapezium to pisiform and hamate, forms anterior border of carpal tunnel

Carpal tunnel

Holds tendons of flexors

Fibrous flexor sheaths of fingers

Anchored to ridges along sides of phalanges on palmar aspects, hold flexor tendons in position close to palmar aspect of phalanges

Dorsal interossei

Attached to dorsal aspect of metacarpals along their sides, and to bases of proximal phalanges, spread (abduct) the fingers, make u-shaped attachment marks on dorsal aspect of 2nd-5th shaft

Endochondral ossification

Begins as hyaline cartilage precurser, cartilage ramines at some spots until end of skeletal growth, chondrocytes m

Growth plate

An organized area in which cartilage grows and then transforms into bone, allows the longitudinal growth of bone

Regions of the growth plate

Resting zone, zone of proliferation, zone of hypertrophy, zone of calcification, zone of ossification

Epiphyseal line

When growth has cease and the plates transform into bone

Remodelling

Coordinated resorption and apposition of bone

Key sources of childhood physiological stress

Malnutrition and disease

Children with growth delay may show

Reduced body size for age, delays in skeletal development, delayed onset of puberty, delayed completion of skeletal growth

Catch up growth

If nutrition/health improves, growth will accelerate above normal rate for a while

Linear enamel hypoplasia

Transverse grooves or series of pits in the surface of the enamel, enamel laid down in layers by ameloblasts as tooth forms, systemic stress causes cessation of activity in a group of ameloblasts, tooth formation continues, may be lost later in adulthood if tooth is worn down by use

Estimation of stature used for

Forensic studies, bioarcheology

Living stature reflects

The total height of the feet, legs, hips, spine and skull

Stature begins to decline after

30

Primary functions of the pelvic girdle

Link between spine and lower limb, origin/insertion for torso and hip muscles, support of internal structure

Gluteal muscles

Gluteus minimus, gluteus medius, gluteus maximus

Gluteus minimus and gluteus medius

Run to greater trochanter of the femur, abduct the femur, maintain level pelvis while walking

Gluteus maximus

Runs to femur, a portion attaches to the gluteal line of the femur, extension of the femur, important for walking, climbing, running

Soft tissue structures of the knee

Menisci, cruciate ligaments, collateral ligaments

Menisci

Medial and lateral, run along edges of tibial condyles and build them up, crescent shaped, sit on top of articular cartilage, ends of crescents attach to bone of tibia in anterior and posterior intercondylar areas

Cruciate ligaments

Anterior and posterior, arise from intercondylar fossa of femur, insert on intercondylar areas of tibia

Collateral ligaments

Fibular and tibial, lateral and medial epicondyles of femur

Quadriceps femoris

Four heads running from os coxae and femoral shaft, unite in a tendon that attaches to the patella

Patella

Increases mechanical advantage, protects knee, larger lateral facet helps prevent lateral dislocation

Muscles of the ankle

Gastrocenmius and soleus

Gastrocnemius

Superficial, two heads attach to femur, attachment of medial head often visible as rough area on popliteal surface

Soleus

Runs under gastrocnemius, attaches to shaft of tibia and head of fibula, tibial attachment point is popliteal line

Achilles tendon

Lifts rear of calcaneus around fulcium of talcrural joint, entire foot lifts off ground to point of metatarso-phalangeal joint, frequent site of stress lesions

Flexor hallucis longis

Flexes ankle and first toe, tendons run in grooves on calcaneous and talus, runs between MT 1 sesamoids, which steady and protect the tendon

Arches

Aid in weight distribution, principal arch in longitudinal arch on medial aspect, from calcaneal tuberosity to head of first metatarsal, shape of arch is present in shape of bones, but maintained by ligaments and tendons

Plantar fascia

Strong superficial sheet of tendon on sole of foot, attached to calcaneal tuber and to fibrous sheaths of the phalanges of the toes

Bone turnover

Eventually all bone tissue in a bone will be replaced

Wolff’s law

Bones adapt to high stress by forming bone where stress is high and resorbing it where stress is low

Paleopathology

The study of illness, trauma, and other health issues in past individuals and populations using their physical remains

Anomaly

Any change in the remains that appear to be outside the range of normal variation

Lesion

An area of tissue that has been pathologically altered

Blastic lesion

Deposits excess bone, common cause is reaction of periosteum to bleeding or inflammation

Lytic lesion

Removal of bone, can be caused by pressure from products of infection

Mixed lesion

Shows blastic and lytic components

Active/recent lesions

Shows sharp edges, depositional bone present is woven

Perimortem lesions

Inflicted shortly before, at, or after death, shows no bone reaction

Fracture

Bone breaks under mechanical stress

Dislocation

Joint separates under mechanical stress

Joint diseases

Degenerative joint disease, traumatic and septic osteoarthritis, rheumatoid arthritis

Infectious diseases

Most leave no skeletal lesions or non-specific lesions

Metabolic diseases

Abnormalities of bone quality or quantity can be caused by dietary and hormonal problems

Dental diseases

Dental carries, periodontitis, abscessing

Enthesis

The point where a tendon, ligament, or joint capsule attaches to a bone

Fibrous enthesis

The ligament/tendon joins to the bone via fibrous connective tissue only, not useful for reconstructing past activity patterns

Fibrocartilaginous enthesis

The ligament/tendon attaches to the bone via a fibrocartilaginous transition zone, show dry bone changes that seem to be more clearly linked to activity

Osteoarthritis

Deterioration of articular cartilage, mechanical stress increases likelihood, as well as severity of lesion, show some links to activity