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Lab Week 6The Skeletal System

Vertebral Column

• Structure– Vertebrae (26 bones)– Intervertebral discs

• Functions– Protection– Support– Movement

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Vertebral Column

• Curvatures– Increase the resilience and flexibility of the spine

• 2 posteriorly concave curvatures– Cervical and lumbar

• 2 posteriorly convex curvatures– Thoracic and sacral

Vertebral Column

– Abnormal spine curvatures• Scoliosis (abnormal lateral curve)• Kyphosis (hunchback)• Lordosis (swayback)

Intervertebraldisc

Intervertebral foramen

Anulus fibrosus

Nucleus pulposus

Sectioned bodyof vertebra

Transverse process

Sectionedspinous process

Ligamentum flavum

Median section of three vertebrae, illustrating the compositionof the discs and the ligaments

Posterior

Anterior

Lamina

Transverseprocess

Pedicle

Spinousprocess

Vertebralarch

VertebralforamenBody(centrum)

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Pectoral Girdle

• A.k.a. Thoracic or shoulder girdle• Components

– Clavicle– Scapula

• Function– Attach upper limbs to axial skeleton– Attachment points for muscles

The Pelvic Girdle

• Components– Ossa coxae (hip bones)

• Ilium• Ischium• Pubis

• Function– Supports trunk– Leg attachment

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Pelvic Girdle

Female Male

General structure Less massive Massive, robust, heavy

Sacrum Broad, less curved Narrow, more curved

Symphysis Shallow Wide

Pelvic inlet Larger, circular Narrower, heart shaped

Pelvic outlet Wide, ischial spines spaced

Narrow, ischial spines close

Pubic arch Obtuse angle >90° Acute angle <90°

Obturator foramen Triangular Oval

Iliac crest Low High