Easy Notes Chapter 7-8 skeletal system

What is the purpose of the axial skeleton?

To provide main support for the body and protect vital organs.

How many bones are in the axial skeleton?

80 bones.

What are the different types of bones in the axial skeleton?

Includes the skull, hyoid bone, auditory ossicles, vertebral column, and thorax.

What bones comprise the adult skull?

22 bones: 8 cranial bones and 14 facial bones.

What is the unique feature of cervical vertebrae?

Cervical vertebrae are the smallest and have bifid (split) spinous processes.

What is the difference between true, false, and floating ribs?

True ribs connect directly to the sternum, false ribs connect indirectly, and floating ribs do not attach to the sternum.

What is the structure of the sternum?

It consists of three parts: manubrium, body, and xiphoid process.

What are the major types of depressions and openings in bones?

Fissures, foramina, fossae, sulci, and meatuses.

What is a herniated disc?

Protrusion of the nucleus pulposus through the annulus fibrosus, often due to trauma or aging.

What are the parts of the vertebral column?

Cervical, thoracic, lumbar regions, sacrum, and coccyx.

What are the components of the nasal septum?

Vomer (bone), perpendicular plate of the ethmoid (bone), and cartilage.

What bones are included in the shoulder girdle?

Clavicles and scapulae.

What are the parts of the ilium in the hip?

Includes the iliac crest.

What are the arches of the foot?

Medial longitudinal arch, lateral longitudinal arch, and transverse arch.

What is the major difference between the male and female pelvis?

Male pelvis is narrower and deeper; female pelvis is wider and lighter for childbirth.

What type of ossification leads to the development of bones in the skull?

Both intramembranous and endochondral ossification.

What are the parts of the femur?

Head, neck, greater trochanter, lesser trochanter, and condyles.

What is the typical composition of skeletal tissue in fetal development?

Initially mostly hyaline cartilage that later ossifies into bone.

What does the coccyx represent in the skeleton?

Forms the tailbone and serves as an attachment site for ligaments and muscles.

What is the function of intervertebral discs?

Provide cushioning between vertebrae.

What is the function of the hyoid bone?

Supports the tongue and provides attachment for neck muscles.

What are the unique features of the cervical vertebrae compared to thoracic and lumbar vertebrae?

Cervical vertebrae are smaller and have bifid spinous processes, while thoracic vertebrae are larger with costal facets and lumbar vertebrae are the largest and thickest.

What are the common disorders of the axial skeleton?

Herniated discs, scoliosis, kyphosis, lordosis, spina bifida, and vertebral fractures.

What is the significance of the mandible?

The mandible is the largest, strongest, and only movable bone of the skull.

What are the major foramina of the skull and their functions?

Carotid Canal (internal carotid artery), Hypoglossal Canal (hypoglossal nerve), Jugular Foramen (internal jugular vein, cranial nerves IX, X, and XI), Foramen Magnum (connects cranial cavity to vertebral canal).

What are the four paranasal sinuses?

Frontal, maxillary, sphenoid, and ethmoid sinuses; they act as resonating chambers for voice.

What are fetal skull fontanels?

Areas of unossified mesenchyme that allow for brain growth, closing by age 2.

What is the structure and function of the sacrum?

Formed from the fusion of five sacral vertebrae; connects the spine to the hip bones and provides strength and stability.

What is the coccyx and its function?

Formed from the fusion of four coccygeal vertebrae; serves as an attachment site for ligaments and muscles.

What is the function of intervertebral discs?

Provide cushioning between vertebrae.

What are the main differences between the false and true pelvis?

False pelvis supports the intestines; true pelvis defines the birth canal.

What are characteristics of the male vs. female pelvis?

Male pelvis: narrower, heavier, and deeper for bipedal locomotion; Female pelvis: wider, lighter, and broader for childbirth.