compa 2011 lec4a - skeletal intro and vert col

8/2/2019 Compa 2011 Lec4a - Skeletal Intro and Vert Col

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Skeletal System

Comparative Vertebrate Anatomy

Lecture Notes 4a

John Donnie A. Ramos, Ph.D.Dept. of Biological SciencesCollege of ScienceUniversity of Santo Tomas

Osteoporosis

condition characterized by the loss of the normal density

of bone, resulting in fragile bone.

Result from disease, dietary or hormonal deficiency or

advanced age

Osteogenesis Imperfecta

Geneticdisorderresultingtoimperfectlyformedbonescausedbyinadequateamountofbonecollagen

Avascular Necrosis

Deathofbonetissueresultingfromtemporaryorpermanentlossofbloodsupply

Fibrous Dysplasia

chronicdisorderinwhichboneexpandsduetoabnormaldevelopmentoffibroustissueresultingtounevengrowthofbonesandbonedeformity

Osteomyelitis

inflammationorswellingofbonetissueusuallytheresult

ofaninfection(bacteria)ortraumaticinjury


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Functions of Skeletons

Framework / support Form body shape

Locomotion (together with muscles)

Protection (encasement)

Mineral deposit (reservoir)

Blood cell formation

Attachment of muscles

Skull determines shape of head

Triangular Face Round Face

Oblong FaceSquare Face

Skeleton

.any mineralized/hardened portion of the body

(bone, dentin, cartilage, enamel)

Origin: mesoderm

Epimere

(vertebral column)

Hypomere

(appendicular

skeleton)

Development of Skeleton

Mesoderm

Epimere / Hypomere

Sclerotome / Limb buds

(Scleroblasts)

ChondroblastOsteoblast Odontoblast Ameloblast

Bone Cartilage Dentin Enamel

Collagen

Bone Structure

Diaphysis

Epiphysis

Epiphyseal plate

Haversian System

Deposition ofHydroxyapatite Crystals

Osteon Haversian canal


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Bone Structure

Periosteum

Endosteum

Types of Bones Compact bone

Found on shaft of long bones and flat bones

Lamellae arranged in haversian system Without cavities except haversian canals

Spongy bone Found in epiphysis (areas of stress) Made up of trabeculae (irregularly arranged lamellae) and

bone marrow (connective tissue fibers, blood vessels, nerves,adipose and hematopoietic cells)

Dentin (Dermal bone) Found in the skin Odontoblasts are not enclosed by lacunae Often covered by enamel

Aspidin (Acellular bone) Bones without cells Enameloid substances

Bone Types (as to how they are formed):

Membrane Bones Directly formed without passing the cartilage

stage

Intramembranous ossification

Replacement Bones Originate first as cartilage

Endochondral ossification

Other Skeletons Cartilage

Collagenous matrix

Chondrocytes

Matrix with mucopolysaccharide

No canaliculi and blood vessels

Tendons Connects muscle with bones

Made up of collagen

Ligaments Connects bone to bones

Made up of collagen

Aponeuroses Flat tendons and ligaments

Sesamoid cartilage Mineralized tendons or ligaments

Ligament Injury

Anterior Cruciate Ligament

Kinds of Cartilage Hyaline cartilage (Nose)

Translucent matrix Absence of fibers aside from collagen Precursor of replacement bones

Fibrocartilage (Intervertebral discs) Presence of thick collagen fibers

Elastic cartilage (Ear, epiglottis) Contains both collagenous and elastic fibers

Calcified cartilage (jaws of sharks) Deposition of calcium salts


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Arthrosis attachment of two bones by ligaments Diarthrosis

Freely movable joint

Surfaces with hyaline cartilage Enclosed by synovial membrane with synovial fluid

Amphiarthrosis Limitedly movable

With fibrocartilage

Absence of synovial fluid

Synarthrosis Immovable

Sutured joints

Ankylosis condition when sutures becomes obliterated

Symphysis Special joint in the midline of the body

Separation of bilateral bones

Joints

Joints

Suture(immovable)

Pubic Symphysis(slightly movable)

Hinge Joint(Moderate movement)

Ball and Socket Joint(Moderate movement)

Skeletal RemodelingAbility of bones undergo growth, repair

and maintain homeostasis

Preskeletal mesenchymal blastemas

Cartilage

Resorption

Replacement Bones

Chondrogenesis

Endochondral Ossification

Continual resorption and remodelling

Membrane Bones

IntramembranousOssification

Caring for your bones

Eat healthy

Have a regular exercise

Take bone supplements

Have a bone density check-up

Have a healthy mind and spirit- pray!

Vertebrate Skeleton

Axial Skeleton Notochord and vertebral column

Ribs and sternum

Skull and visceral skeleton

Appendicular Skeleton Pectoral and pelvic girdles

Skeleton of paired fins and limbs

Skeleton of median fins of fishes


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Heterotopic Bones

Developed on areas of stress

Endochondral or intramembranous ossification Found in internal organs

Examples: Os cordis (interventricular septum of deer and

bovine heart)

Baculum or os penis (dog and primate penis)

Os clitoridis (mammalian clitoris)

Patella (human kneecap)

Heterotopic bones in dove gizzard, bat tongue,camel diaphragm, bird syrinx etc.

Vertebral Column

Attachment of skull, limbs and ribs

Encloses and protects the spinal cord

Part of the cage that protect internal organs

Attachment of muscles

Formed as a cartilage around and within thenotochord Perichordal cartilage (around the notochord)

Chordal cartilage (invade the notochord)

Pulpy nucleus remnants of the notochord atthe centrum

Typical Vertebrae Structure

Vertebrae Types based on shape of centra

Amphicelous (fish) Concave on both ends

Procelous (frog) Concave anterior, convex posterior

Opisthocelous (turtle) Convex anterior, concave posterior

Heterocelous (birds) Saddle shape of both ends

Amphiplatyan (man) Flat on both ends

Apophyses (transverse processes)

Zygapophysis Articulation between vertebrae

Prezygapophysis (cephalic) Postzygopophysis (caudal)

Basapophysis Attachment of unicipital rib

Diapophysis Attachment of tuberculum (upper head of bicipital rib)

Parapophysis Attachment of capitulum (lower head of bicipital rib)

Pleuropophysis Transverse process for muscle attachment

Hypapophysis Midventral processes for muscle and tendon attachment


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Apophyses Fish Vertebrae

Diplospondyly - presence of 2 centra

- increased flexibility for

locomotion

Dorsals Caudals

Shark Vertebrae Tetrapod VertebraeRegional Specialization

Cervical - scan environment Atlas (attachment with skull)

Axis (2nd vertebra)

Thoracic attachment of ribs

Lumbar area without ribs

Sacral attachment of pelvic girdle Sacrum (ankylosed sacral vertebrae in mammals)

Synsacrum (ankylosed last thoracic, all lumbar allsacral and first few caudal vertebrae of birds)

Caudal locomation, balancing Urostryle

Pygostyle Coccyx

Necturus Vertebrae

Trunk vertebraeCaudal vertebrae

Frog Vertebrae


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Alligator Vertebrae

Caudal Thoracic Cervical

Turtle Vertebrae

BirdVertebrae

Pigeon Vertebral Column

Cat Vertebrae Cat Vertebrae


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Sacrum and Synsacrum Hen Synsacrum and Pelvic Girdle

Lateral View

Ventral View

Pelvis of Archeopteryx

Lateral View

Ventral ViewDorsal View

Lateral View

Caudal Vertebrae

Lateral View

Urostyle

PygostyleCoccyx

Ribs main case of visceral organs

Fishes (unicipital ribs) Dorsal ribs (separates epaxial from hypaxial muscles

Ventral ribs

Tetrapods Bicipital ribs

Tuberculum (dorsal head)

Capitulum (ventral head)

Parts of Amniote Thoracic Ribs Costal ribs

Sternal ribs

Bicipital Ribs


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Tetrapod Sternum

o amniote skeletono endochondral origin

o found on the ventral side of the body

o base of pectoral girdles and braces the ribs

o modified into carina in birds

o made up of sternebrae in mammals

Tetrapod Sterna

Development of Sternum

Origin: Mesenchymal bars

o Sternal bars sternebrae

o Sternal ribs ventral ribs

o Presternal blastema manubrium

o Suprasternal blastema suprasternalossicles (heterotopic bones)

compa 2011 lec4a - skeletal intro and vert col

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