anatomy test 2

Anterior and mastoid fontanelles fuse

2 years postnatal

Tibia

2nd largest bone in body• Articulates with femoral condyles (superiorly) and talus (inferiorly)• Transmits forces of body weight

Sphenoid and posterior fontanelles fuse

6 months postnatal

Acromial end of clavicleAcromion (scapula) Joint Classification: Plane Reinforced by ligamentous connections between clavicle and scapula Permits rotation "Separated shoulder- dislocation or injury to ligaments"

Acromioclavicular Joint

Pubic Symphysis

Anterior articulation between L and R pubic bones• Consists of fibrocartilaginous disc between two symphyseal surfaces of pubic bones

Synovial

Articular capsule lined by serous synovial membrane encloses joint• Freely movable

The intraembryonic coelom has formed around the cranial end and has began to subdivide. They will form the four adult body cavities: Pericardial cavity Two pleural cavities Peritoneal (abdominopelvic) cavity.

As a recap what does the embryo look like at the end of week 3?

features important for artiuclartion with occipital bone No body No spinous process-posterior and antetiror tubucle No articular process

Atlas unique features

Deltoid tuberosity (lateral)

Attachment for deltoid m.

Dense process (fits with c1) - pivot for rotation of the atlas

Axis unique features

Lesser/True Pelvis

Between pelvic inlet and outlet/perineum• Physically bounded by os coxae, sacrum, and coccyx• Includes pelvic cavity + viscera and perineum• Major OBGYN significance

Articular AA supply parallel articular vv drain large joints have anastomoses

Blood supply of joints?

Fibrous

Bones joined by fibrous tissue

Cartilaginous

Bones joined by hyaline cartilage or fibrocartilage

Long spinous process Does not transmit vertebral artery Spinous process easily palpable (longer trans between cervical and throacix vert)

C7 unique features

Atypical ribs 11-12 lack a tubercle to define the neck , reduced anglulation smaller and flatter 1,2 shorter flatter and more angultion

Characteristics of atypical ribs

Smallest and most mobile Typical (C3-C6) vs. atypical (C1, C2, C7) Defining Characteristics:Transverse foramina (contain vertebral artery)Spinous process may be bifed (2 points instead of 1 point)

Characteristics of cervical vertebrae

Most weight bearing Largest bodies Quadrangular spinous processes Mammillary processes- extra process for added stabilization

Characteristics of lumbar vertebrae

Attachments for ribs (costal facets) Heads of ribs articulate with 2 (ant and post) adjacent costal facets Tubercles of ribs articulate with transverse costal facets Long spinous processes longest at T 11 but still has facet

Characteristics of thoracic vertebrae

Palpable along entire length Forms the anterior part of the pectoral girdle One of the most frequently fractured bones, especially in children- in the middle 3rd of the shaft and mostly from indirect result Usually results from fall on outstretched hand (FOOSH) or direct trauma to shoulder

Clavicle characteristics

Results from forced dorsiflexion of the hand, such as in breaking a fall with an outstretched, pronated hand Complete transverse fracture within the distal 2 cm of the radius Distal fragment displaced dorsally, giving the classic "dinner fork deformity"

Colles' Fracture- distal radial fractures

Anencephaly

Cranial vault doesn't form Failure of closure of cranial neuropore

primary curves - develop in fetal period (thoracic and sacral) dont change secondary curves- develop towards end of fetal period fully developed at different points cervical develops fully at 1 year (hold their head up) lumbar develops around walking and standing period cervical and lumbar- inward Lordosis(extreme curve) concave posteriorly thoracic and sacral- hypototic (extreme curve) or outward concave anteriorly -cruvatures develop to aid the activity

Curvatures of the vertebral calcium

-Mesenchyme differentiates into cartilage and forms a model of the bone, surrounded by perichondrium -Chondrocytes enlarge and resorb part of the cartilage -Cartilage undergoes calcification, chondrocytes die leaving the hardened matrix -Throughout these processes, blood vessels invade perichondrium -Progenitor cells differentiate into osteoblasts; perichondrium is now periosteum-on the hardened matrix -Osteoblasts form periosteal bone collar

Describe the general steps of Endochondral Formation

-Mesenchymal cells differentiate into osteoblasts -Osteoblasts secrete osteoid at multiple ossification centers -Osteoid is calcified -Ossification centers fuse to form bone -Mesenchyme that doesn't form bone becomes bone marrow

Describe the general steps of Intramembranous Formation

Stability and Movement of the Forearm Humeroulnar and humeroradial joints Radioulnar joint* elbow 3 joints in one joint capsule provide stability and movement of forearm

Elbow Joint

Joint capsule

Encloses joint• Fibrous outer layer, synovial membrane as inner layer

mouth and ear Maxilla and mandible Muscles that control the jaw (muscles of mastication) Incus and malleus of inner ear

First arch:

Articular Disc

Found in some joints where articulating surfaces are incongruous• Ex// temporomandibular joint, sternoclavicular joint, proximal wrist

Muscles of the larynx Thyroid cartilage of the larynx Aortic arch

Fourth arch:

Support Protection Movement Storage Blood cell formation

Functions of the Skeleton

5 Regions: Cervical (7)-neck Thoracic (12)-thorax Lumbar (5)-lower back Sacral (5)-fused Coccyx (4)-fused Increase in size inferiorly- less load cranially and load increases as you move down

General vertebrae structure

Glenoid cavity (scapula)Humeral head Joint Classification: Ball and socket Reinforced by muscular, ligamentous, and fibrocartilaginous structures Permits flexion/extension, medial/lateral rotation, abduction/adduction, and circumduction stable but highly mobile: all listed in photos "Dislocated shoulder-easily dislocated"

Glenohumeral Joint

Pelvic fractures

Great force needed• Ex/ automobile accident• Pelvic ring: Creates at least two breaks• Transferred force: lower extremity trauma

Coxa Valga/ Bow Legged

Greater angle of inclination (>140o)

Nerves supplying the muscles moving the joint & overlying skin also supply joint Few exceptions in hands & feet where articular nn. = cutaneous nn branches

Hilton's law

• Congenital dislocation common in neonates• Acquired dislocation uncommon• Requires great force• Usually posterior • Ex// automobile accident

Hip (Femoroacetabular) Joint dislocations

all

Hip (Femoroacetabular) Joint movements

-mesenchymal cells differentiation into hemanigoblast which will differentiate into angioblast and hematopoietic stem cells. hemangioblast coagulate and form blood island where angioblast will eventually form the endothelium of the blood vessels and the Hemangioblast will form HPSC for blood cell development -Day 18: capillaries form in intraembryonic splanchnopleuric mesoderm

How does angiogenesis occur in the embryo

circulatory development begins to develop in the yolk sac with the induction of hemangioblastic cells in the yolk sac around week 5.. however before the cells undergo differentiation for vessel formation we need to develop our primitive heart The cardiac crescent, which contains a primary and secondary heartfield, stems form the development of cells in the anterior splanchnic mesoderm. These form the cardigogenic area with a cardiac crescent that is flanked on either end by future atrium. -Lateral folding cause the two ends of the crescent tubes to merge into a single heart tube that begins to beat around day 21-22 -cranial caudal folding causes the heart to orient correctly with atrium over ventricle

How does folding affect heart formation?

1. Upper body weight transferred to pelvis (SI joint) through vertebral column 2. Ilia + sacrum transfer weight laterally through pelvic arch 3. Ilia transfer weight to obliquely oriented femurs @ hip 4. Pubic rami complete arch and maintain structural integrity by forming struts or braces

How is weight transferred in the body?

Trochlea (humerus)Trochlear notch (ulna) Capitulum (humerus)Head of radius Joint Classification: Hinge joint Permits flexion and extension humeroradial joint primary joint action is flexion and extension some contribution to protonation and supination

Humeroradial Joints

Joint Classification: Hinge joint Permits flexion and extension humeroulnar joint

Humeroulnar joint

In both processes, woven bone appears first and is replaced by laminar bone secondary bone tissue

In both processes of bone formation, ________ appears first and is replaced by ________ bone secondary bone tissue

triradiate cartilage

Infants/children os coxa• Ilium, ischium, & pubis unfused• United by ______________ at acetabulum

Pelvic Outlet

Inferior Pelvic Aperture Comprised of bony and ligamentous structures

Primary cartilaginous joints aka synchondroses

Joined by hyaline cartilage• Permits slight bending• Usually temporary • Join epiphyses & metaphyses during long bone development• Epiphyseal plate or "growth plate"

Intercarpal- carpal carpal Carpometacarpal- carpal to meatacrapal Intermetacarpal- metacarpal to metacarpal

Joints of the Hand

Flat articular facet Articulates with acromion (scapula) at acromioclavicular joint

Lateral (Acromial) End clavicle

Radius

Lateral, shorter bone of the forearm that participates in radiocarpal (wrist) joint- rotates radius is rad thumbs up and out in anatomical position

coxa vara ("knock knees")

Lesser angle of inclination (<120o)

Synovial membrane

Lines all internal surfaces not covered by articular cartilage• Produces synovial fluid

Articular cartilage

Lines articulating surfaces of bones

Femur

Longest, heaviest bone• Transmits weight from pelvic girdle to tibia

All-around mobility, poor in rotation because its set for weight bearing Mostly used in flexion/extension

Lumbar movement

L5 & S1 at anterior intervertebral joint Posterior zygapophyseal joints (2) between articular of segments

Lumbosacral joint articulates with

Stability and movement of the pectoral girdle Only true articulations between axial skeleton and upper limb Allow for a highly mobile upper limb compared to lower limb

Main Articulations of the Pectoral Girdle

Accessory ribs

Mainly result of misexpression of Hox genes Retention and subsequent growth of costal processes of cervical or lumbar vertebrae

R. and L. os coxa (innominates)• Fused ilium, ischum, & pubis• Sacrum • Axial skeleton and pelvic girdle

Mature pelvic girdle formed by three bones

Enlarged and triangular articular facet Articulates with manubrium at sternoclavicular joint

Medial (Sternal) End clavicle

eye- cornea

Mesoderm

Fused ribs

Multiple ribs arise from same vertebra Can be associated with hemivertebrae

Hemivertebra (scoliosis)

Mutation of genes that mark position of somites Wedge shaped vertebrae= Results from failure of chondrification center to appear

Choroid and Sclera-eye Bony labyrinth-ear

Neural crest cells

Retina

Neuroectoderm

Fibula

No function in weight-bearing• Acts as muscular attachment site• Stabilizes ankle

Spina bifida

Nonunion of vertebral arches

Radiographs of hands and wrists sometimes used to assess skeletal age Ossification centers appear postnatally in carpals (center) and metacarpals (heads & bases) Epiphyseal plates of long bones (i.e., radius & ulna) are apparent in children

Ossification of Bones in the Hand- estimate ____________ based on standard pattern of development

7 tarsals•5 metatarsals•14 phalanges•2 sesamoids

Osteology of the Foot

Extrinsic accessory ligaments

Outside of the articular capsule• Strengthen the joint capsule • Medial & lateral collateral ligaments of the knee

Gomphosis (dentoalveolar syndesmosis)

Peg-like process fits into a socket• Proprioception• Movability = pathology

greater (false) pelvis, lesser (true) pelvis

Pelvic Divisions

Ossicles (1st and 2nd arch)- ear

Pharyngeal arch

ear- External acoustic meatus (1st groove)

Pharyngeal groove

ear-Tympanic cavity, Auditory tube (1st pouch

Pharyngeal pouch

Joint Cavity

Potential space, contains synovial fluid

• Tubotympanic recess (middle ear) and Eustachian tube• Membrane = tympanic membrane

Pouch 1:

• Palatine tonsils and tonsillar fossa

Pouch 2:

• Superior extension: inferior parathyroid glands• Inferior extension: thymus

Pouch 3:

Superior extension: superior parathyroid glands• Inferior extension: ultimobranchial bodies

Pouch 4:

Craniosynostosis

Premature closure of any of the sutures 1-2500 live births Feature in over 100 genetic syndromes Most common cause - genetic Others - Vitamin D deficiency, teratogen exposure, oligohydramnios

Support full weight of upper body• Support and protect abdominopelvic organs• Provide attachments for muscles and membranes• Transfer of forces

Primary functions of the pelvic girdle?

Distal end of radius Scaphoid and lunate Articular disc of ulna articulates with lunate and triquetrum to add stability, absorb shock, and help support distal radioulnar joint Permits flexion, extension, ulnar deviation pinkie towards arm and radial deviation thumb towards arm, and circumduction

Radiocarpal (Wrist) Joint

Proximal: head of radius and radial notch of ulna Distal: head of ulna and ulnar notch of radius Joint Classification: Pivot joint Permits pronation and supination Pronation and supination occurs at proximal radio-ulnar joint In pathological cases, anatomical features and orientation must be restored for normal function Radius pivots around the ulna Radial head in radial notch (superiorly), ulnar head in ulnar notch (inferiorly). These areas are what allow the radius to pivot around the ulna during pronation and supination.

Radioulnar Joints

Accessory ligaments

Reinforce joint

Transfers weight of upper body to pelvic girdle

Role of the lumbosacral joint?

Stability over movement

Sacroiliac Joints favors ______________

Most commonly fractured carpal bone MOI: falling on palm when hand is abducted Pain on lateral side of wrist Might not initially see on X-ray- re xray in a couple of weeks to make sure nothing is missed Risk of avascular necrosis- can cause damage to the joint causing degeneration of wrist

Scaphoid Fracture

Fractures relatively uncommon, result from severe trauma (e.g., getting struck by a car)- because its so protected by muscle little intervention needed muscles protect for healing elevation depression protraction retraction upwards and downwards rotation adduction of hand

Scapula characteristics

Stapes of inner ear Upper part of hyoid bone Muscles of facial expression

Second arch:

Shoulder/ Pectoral Girdle Clavicle, Scapula Arm Humerus shoulder to elbow Forearm Radius, Ulna elbow to wrist Hand wrist down Carpals, Metacarpals, Phalange

Segments of the upper extremity

diaphragm

Septum transversum

females greater than 90 degree angle. sacrum tilted back, ilia are spread wider

Sex differences in the pelvis?

Muscles of the larynx Laryngeal cartilages- NCC Pulmonary arteries

Sixth arch:

Anencephaly Microcephaly Craniosynostosis

Skull defects

Spondylolisthesis

Slippage of vertebral body anteriorly Elongation of the pars interarticularis

Microcephaly

Small neurocranium with overlapping sutures that fuse

Avulsion fractures

Small part of bone with a piece of tendon or ligament attached is torn away• Occur at bony projections • Ex/ ischial tuberosity avulsion

joint bursae

Small sac or envelope of serous membrane• Potential space• Houses small amount of lubricating fluid• Occur in locations subject to friction• Allow one structure to move freely over another

Articular labra

Soft cartilage rim around outer margins of joint deeper socket• Femoroacetabular and glenohumeral joint

part of the parietal mesoderm: somatic mesoderm and overlying ectoderm

Somatopleure

Vitelline arteries -> bring in nutrients from the yolk sac from the superior messenteric artery Umbilical arteries -> developing placenta- will degenerate

Special arteries?

Part of the visceral mesoderm: splanchnic mesoderm and adjacent endoderm, will help form viscera.

Splanchnopleure

Interosseous Membrane

Stabilizes tib-fib relationship• Muscle attachment site• Passage for neurovascular structures

Sternal end of clavicle, Manubrium, 1st costal cartilage- mobile and strong Joint Classification: Saddle Reinforced by strong ligaments Permits rotation and some gliding reinforced by strong ligaments infrequent dislocation

Sternoclavicular Joint

pelvic inlet

Superior Pelvic ApertureComprised of rigid, bony structures

greater (false) pelvis

Superior to pelvic inlet• Physically bounded by iliac alae & S1 vertebra• Occupied by abdominal viscera•

Optic placode, Lens-eyes Otic placode, Membranous labyrinth-ear

Surface ectoderm

articular nn.

Tansmit sensory impulses from the joint that contribute to proprioception

Lower part of hyoid bone Internal carotid artery

Third arch:

All-around mobility, best in rotation

Thoracic movement

stress fracture transverse fx in distal third• Activity related • Trauma (hit while foot stabilized)• Dramatic increase in hiking/running

Tibial fracture related to activity

Intramembranous Bone directly replaces mesenchyme Endochondral Bone is preceded by a cartilage model

Two types of bone formation?

-plane -hinge -saddle -codyloid -ball and socket -pivot

Type of synovial joints

Sutures of the skull Syndesmosis Gomphosis (dentoalveolar syndesmosis)

Types of Fibrous Joints

Articulate with thoracic vertebrae posteriorly Anterior articulation differs- most with sternum True ribs (#1-7) attach directly to sternum via costal cartilage False ribs (#8-10) form an indirect attachment to sternum via costal cartilage Free/floating ribs (#11-12) have no anterior attachment

Types of Ribs

Secondary cartilaginous aka symphyses

United by fibrocartilage • Strong but slightly moveable• Permanent• Pubic symphysis• Intervertebral discs

early- Somites begin to form late- Sclerotome migrates around neural tube and notochord (beginning of vertebrae formation)

Week 4?

Sclerotome splits and notochord regresses

Week 5?

Ossification centers form in the vertebral arch; Sternal bars fuse

Week 8?

Sacroiliac Joints

Weight-bearing component formed by:1. Auricular surfaces of sacrum and ilium • Synovial joint but limited mobility2. Fibrous joint between iliac and sacral tuberosities• Syndesmosis

Fibrous Cartilage Synovial

What are the 3 classes of joints?

Paraxial mesoderm- Scleretomes. Sclerotomes form vertebrae, ribs, and posterior cranium Lateral plate mesoderm- Parietal layer. Forms appendicular skeleton (limbs & limb girdles) and sternum Neural crest cells- ectoderm. Anterior craniofacial bones

What are the 3 progenitors to skeletal components?

-First heart field: cariogenic cresent -second heart field:-true heart

What are the two parts of the cariogenic region?

Placode - thickening of the surface ectoderm Otic -> ear Optic -> eye Both placodes develop around day 22-compared to the heart take longer to form

What are the two placodes and when do they develop?

pouches form glands pouch 1 is the exception it makes the eustachian tube and typmanic membrane- inside is endoderm outside is ectoderm

What do the pouches form? What is the exception?

Parietal (somatic) mesoderm: Somatopleure - somatic mesoderm and overlying ectoderm, will help form the body wall.- defects in anterior body way will be issues with this closing Visceral (splanchnic) mesoderm: Splanchnopleure - splanchnic mesoderm and adjacent endoderm, will help form viscera-cover the organs

What does each layer form?

venous system will stem from your cardinal veins 3 cardinal veins: Anterior cardinal vv. - cranial end Posterior cardinal vv. - caudal end Common cardinal vv.- where they fuse All come together to form sinus venosus, continuous with heart tube

What happens during venous development?

Verebral disorders such as: Hemivertebra-scoleosis Spondylolisthesis Spina bifida

What happens if we have hox gene product distibuted irregularly during scleirtomal formation of vertebrae?

primary ossification centers forms first in the shaft bone will ossify the hyaline cartilage to form a periosteum layer secondary ossification centers- will form in the epiphysis and harden the interior leaving the hyaline cartilage for growth between the two centers and the articular cartilage on the head in both calcification of cartilage replaces it with bone fuse when growing in complete

What is the difference between the primary and secondary ossification centers?

Vasculargensis: new vessels from angioblast angiogenesis: new vessels are developed from the budding of of endothelial cells of an existing vessel embryos do vasculargensis

What is the difference between vasculargeneis and angiogenesis?

Head and neck project superomedially into acetabulum at angle relative to obliquely-oriented shaft• Straightest at birth and becomes more acute with age• Adult average: 126o; Adult range: 115o-140o • Angle is less in females - wider pelvis

What is the femoral head angle of inclination?

-Rapid growth of neural tube/somites elongates embryo -Cranial end and caudal end fold towards each other -Portion that will form brain -> most cranial feature -Structures that were cranial to neural plate pulled ventrally -> reversing their orientation. ex) septum tranversum and the heart are most cranial but will comes down to the right location under the head with the heart above the septum transversum -part of the endoderm will be encoporated into the gut

What is the outcome of cranial caudal folding?

lateral plate mesoderm moves ventrally in and the somatopleura fuse forming a closed body wall except at the Opening to yolk sac which narrows to form the vitelline duct Gut tube forms as embryo folds (endoderm continuous with yolk sac)

What is the outcome of lateral folding?

-arches that develop in the embryo and develop it into specific tissue structures. core contains mesoderm and neural crest cells which will differentiation into structures. Neural crest cells will make the cartilage for each arch Pharyngeal groove - external- extoderm Pharyngeal pouch - internal- endoderm

What is the pharangyeal complex?

Femoroacetabular joint

What joint is being fixed in a hip replacement?

Secondary cartilaginous joint

What kind of joint is the pubic symphysis?

Parietal (somatic) mesoderm-directly around the notochord Visceral (splanchnic) mesoderm

What layers of mesoderm form in the Intraembryonic Coelom?

-Folding: flat to tube in tube -Pharyngeal arches form -Neural tube closes The heart and rudimentary circulatory system are formed; heart begins to beat Ectodermal sensory placodes form (will form parts of eye, nose and ear) Limb buds begin to form

What major events occur in the 4th week?

Articular cartilage erodes with age • Less effective at shock absorption & less lubricated• Vulnerable to friction during movement

What occurs with degenerative joint disease?

Early blood cells only produced in yolk sac Will not Undergo hematogenesis until week 5

Where does early blood cells from in the embryo?

Fontenelle

Wide areas of fibrous tissue where sutures eventually form

Spondylocostal dystosis

Widespread malformations of the vertebral column and ribs Genetic malformation that affects for somite formation and segmentation

tibia at the ankle joint fibula does so in a minor way

__________primarily articulates with the talus

Hinge

ankle joint type

tympantic

associated with the external auditory meatus

Cranium/skull Auditory ossicles Hyoid Vertebral column Ribs Sternum

axial skeleton consist of

Newborn calvaria

bones do not fully contact each other• Allow for rapid brain growth

Lateral and medial malleoli as well a distal fibula are common fracture sites • Excessive inversion or eversion of the foot can cause ligaments to stretch, which may cause a bone fracture

common ankle fractures

saddle synovial joint

concave/convex articulations, biaxial• 1st carpometacarpal joint

injury will affect humeral head suprachondylar fracture- most common elbow fracture in children

distal fracture of humerus

Intrinsic accessory ligaments

encorporated into the wall of articular capsule• Oblique popliteal ligament

osteoarthritis • Common in older individuals• Usually affects joints that support body weight • Stiffness, discomfort, and pain (particularly with movement)

examples of DJD?

Fall from heights- calcinal fracture (Comminuted fractures) Extreme dorsiflexion can result in fractures of the talar neck• e.g., rapidly and forcefully stomping on the brake pedal of a car Dropping heavy objects onto the foot can result in metatarsal or phalangeal fractures Forceful inversion of the ankle can result in a fracture to the tuberosity of the 5th metatarsal

foot fractures

plane synovial joint

gliding or sliding in plane of artic. surfaces• Acromioclavicular joint

body of ilium

green area

Peripherally, the interzonal mesenchyme forms the joint capsule and other ligaments for controling movement. Centrally, the mesenchyme disappears, and the resulting space becomes the joint cavity (synovial cavity).

how are synovial joints able to develop in enclosed capsule of synovium?

Intramembranous- comes from messenchyme that did not ossify whereas in endochondrial Osteoclasts remove bone from inside of diaphysis, creating medullary cavity

how is bone marrow formation different in intramembranous bone formation and endochondrial bone formation?

Intracapsular ligaments

inside of the articular capsule • Anterior cruciate ligament and posterior cruciate ligament

anastomoses

location where blood vessels communicate • Ensure that there is always adequate blood supply in area

Secondary cartilaginous joint

lumbosacral joint is what type of joint?

petrous portion

meaning "hard" - contains and protects the inner ear. This portion also includes the mastoid process (much of this portion is within the cranial cavity and is not visible in this view)

Ulna

medial, long, stabilizing bone of the forearm- fixed

Junction of middle and inferior third of shaft most common• Narrowest • Fxs often compound

most common tibia fracture

anteiror May indicate increased intracranial pressure (bulging), dehydration (depressed)

most prominent fontanelle

Movements: dorsiflexion/plantarflexion

movements of the ankle joint

Ball & socket

multiaxial, highly mobile• Femoroacetabular joint (hip)

- commonly children - commonly adults

neck fracture radius head fracture radius

yellow-squamous tympanic- pink blue-petrous

parts of the temporal bone

Radial groove (posterior)

passage for radial n. & profunda brachii a.

viserocranium supports the face

pink

Most "broken hips" are femoral neck fractures• Most common in females over 60yo• Osteoporosis• Risk of avascular necrosis of femoral head

population most sucepetible to femoral fracture

- at surgical neck indirect or direct

proximal fracture of humerus

Condyloid:

range of flexion/extension > narrow range of abduction/adduction, biaxial• Metacarpophalangeal joints (knuckles)

Essentially immovable Sacrum 5 fused vertebrae 4 paired anterior and posterior foramina for sacral spinal nerves Features for the sacroiliac joint (ear shaped) Coccyx Small, triangular bone Formed by fusion of 4 rudimentary vertebrae Attachment for ligaments and muscles

sacrum and coccyx characteristics

direct trauma or twisting of arm displacement can cause injury to structures that run along the boarder

shaft fracture of humerus

vitelline veins Drains fluid from yolk sac Umbilical veins Drains blood from developing placenta

special veins?

The interzone will develop fibrounous mesenchyme. Inside of the mesenchyme there will be degerdation that creates open spots for synovial cavities, the mesenchyme around the cavity will differentiate into your menisci and stabilizing tendons. they mesenchyme exterior to that will remain fibrous and form the joint capsule Synovial Joints- most work

the interzonal mesenchyme between the developing bones differentiates as follows

Fibrous Joints

the interzonal mesenchyme between the developing bones differentiates into dense fibrous tissue.

Cartilaginous Joints

the interzonal mesenchyme between the developing bones differentiates into hyaline cartilage or fibrocartilage ex)Intervertebral discs. Sacrococcygeal symphysis. Symphysis pubis

1. Medial femorotibial2. Lateral femorotibial3. FemoropatellarType: Hinge*

three articulations of the knee

Subcutaneous• Subfascial• Subtendinous• Synovial tendon sheaths

types of bursae

Pivot

uniaxial rotation • Atlanto-axial joint (C1/C2)

hinge synovial joint

uniaxial, flexion & extension • Humeroulnar joint (elbow)

Chondrification centers form in the vertebrae; Joints begin to develop

week 6?

Ossification centers form in the vertebral body and long bones Ossification centers appear in craniofacial bones

week 7?

Hyaline cartilage, the most widely distributed type (e.g., joints)- II Fibrocartilage (e.g., intervertebral discs) -I Elastic cartilage (e.g., auricles of the external ears)- II

what are the 3 types of collagen and what distinguishes them?

Pectus excavatum Depressed sternum sunken posteriorly Pectus carinatum Flattened chest Projection of sternum Resembles a boat keel Caused by an overgrowth of collagen that causes the sternum to keel

what are the various types of pectous defects that can result from problems with the sclerotomes

cartilaginous- Base of the skull and some facial bones- from NCC or the pharyngeal arch Membranous- flat bones of the cranium separated by sutures

what bones are in the cartilaginous cranium vs the membranous cranium?

Proximal section that connects with vertebrae comes form the central sclerotome Distal section attaches to sternum comes form the lateral sclerotome failure can result in Spondylocostal dystosis Fused ribs Accessory ribs

what happens to the ribs with maldistribution of hox genes occurs?

-rapid growth Lateral folding is produced by the rapidly growing spinal cord and somites.

what is perpetuating the folding of the embryo?

transcervical fracture Angle of inclination place considerable strain on femoral neck fractures common• Narrowest and weakest part of bone

what is the most common femur fracture and why?

Clavicle develops from neural crest cells Cleidocranial dysplasia Mutation in Runx-2 gene leads to hypoplasia of clavicle and delayed ossification

what leads to hyperplasia of the clavicle?

after the primitive heart develops the body will generate arteries to carry blood away from the hearts ciruclation -there will be two major portions: those above T4 and those below -Above T4 your arterial arches are branched to feed the head and neck -below T4 the arteries fuse to form a central dorsal aorta. off of this central artery we will have branches called dorsal intersegmental arteries that will grow into the dorsal mesoderm to feed the body

what occurs during arterial development?

Dorsal sclerotome: Neural arch, pedicles, and spinous process Ventromedial sclerotome:Vertebral bodies and annulus fibrosis of intervertebral discs, enclose the notochord into the nucleus pulposus Central sclerotome:Transverse process of vertebrae, proximal portion of ribs Lateral sclerotome: Distal portion of ribs in thoracic vertebrae

what part of the sclerotome merge to form what parts of the vertebrae?

Flat bones of the skull, mandible and clavicles

what type of bones are formed through Intramembranous Formation

osteoclast

when calcification happens trapped osteoblast becomes _________

neocranium protects the brain

yellow

Syndesmosis

• Bones are apart and connected via fibrous membrane or ligament• Partially movable • Interosseous membrane between ulna & radius or distal tibia & fibula

Menisci

• Crescent-shaped• Within the knee joint

sutures

• Immobile• Interlocking or overlapping. -fibronous joint