Skeletal System - Lab & Lec

• What does the term "skeleton" derive from in Greek?

  It comes from the Greek word "skeletos," meaning "dried up body" or "mummy."
• What are the main functions of the skeleton?

  It is adapted for weight bearing, locomotion, protection, and manipulation.
• What are the two main divisions of the skeleton?


  • Axial skeleton: Skull, vertebral column, thoracic cage
  • Appendicular skeleton: Upper and lower limbs, pectoral and pelvic girdle
• How many bones does an adult human have?

  An adult has 206 bones.
• What is the composition of the skull?

  The skull is formed by cranial and facial bones.
• What is the primary function of cranial bones?

  They enclose and protect the brain and provide muscle attachments.
• What do facial bones form?

  They form the framework for the face, cavities for sense organs, openings for air and food passage, hold teeth, and anchor facial muscles.
• What are sutures in the context of the skull?

  Sutures are interlocking, immovable joints where skull bones are firmly united.
• What are the longest sutures in the skull?

  The longest sutures are the coronal, sagittal, squamous, and lambdoid sutures.
• What is the calvaria?

  The calvaria, or cranial vault, forms the forehead region and the superior, lateral, and posterior aspects of the skull.
• What does the cranial base consist of?

  The cranial base forms the inferior part of the skull and is internally divided into anterior, middle, and posterior cranial fossae.
• How many openings are there in the skull?

  There are 85 openings (foramina, canals, fissures) in the skull.
• How many cranial bones are there in total?

  There are a total of eight cranial bones.
• What are the names of the cranial bones?

  • 2 Parietal
  • 1 Frontal
  • 1 Occipital
  • 2 Temporal
  • 1 Sphenoid
  • 1 Ethmoid
• What is the shape and position of the parietal bones?

  Parietal bones are paired, curved rectangles that make up the bulk of the calvaria and form the most superior part of the skull.
• What are the major sutures associated with the parietal bone?

  The major sutures are the coronal, squamous, sagittal, and lambdoid sutures.
• How do the sutures of the parietal bone change with age?

  These sutures become less visible with age.
• What is the frontal bone's primary function?

  The frontal bone forms the forehead and roofs of the orbits.
• What is the significance of the supraorbital foramen in the frontal bone?

  It is where the supraorbital nerve (CN V) and supraorbital artery pass through to supply the forehead.
• What is the glabella in relation to the frontal bone?

  The glabella is the midline smooth part between the superciliary arches underneath the surface of the frontal bone.
• Where are the frontal sinuses located?

  Frontal sinuses are located underneath the surface, lateral to the glabella.
• What is the primary function of the occipital bone?

  The occipital bone makes up the posterior part of the cranium and cranial base.
• What is the foramen magnum?

  The foramen magnum is located at the base of the occipital bone and allows passage for the spinal cord.
• What is the significance of the external occipital protuberance?

  It is located in the midline at the base of the posterior wall of the skull and secures the ligamentum nuchae.
• What do the occipital condyles articulate with?

  The occipital condyles articulate with the first cervical vertebra (Atlas) and enable the "Yes" nod.
• What is the primary function of the temporal bone?

  The temporal bone forms the inferolateral region of the skull and parts of the cranial floor.
• What is the jugular foramen?

  The jugular foramen is where the petrous part of the temporal bone joins the occipital bone and serves as an exit for the internal jugular vein and cranial nerves IX, X, and XI.
• What is the carotid canal's function?

  The carotid canal is a passageway for the internal carotid artery.
• What is the significance of the internal acoustic meatus?

  The internal acoustic meatus is the exit for cranial nerves VII and VIII.
• What is the function of the styloid process of the temporal bone?

  The styloid process serves as an attachment for muscles of the tongue and pharynx, and for a ligament connecting the skull to the hyoid bone.
• What is the mastoid process and its significance?

  The mastoid process contains mastoid air cells, serves as an anchoring site for neck muscles, and contributes to the cranial base.
• What is the shape and function of the sphenoid bone?

  The sphenoid bone is bat wing-shaped and spans the width of the cranial floor, acting as a keystone bone that articulates with every other cranial bone.
• What are the parts of the sphenoid bone?

  The sphenoid bone is composed of one central body and three pairs of processes: two greater wings, two lesser wings, and two pterygoid processes.
• What is the function of the optic canal in the sphenoid bone?

  The optic canal transmits cranial nerve II (optic nerve).
• What is the significance of the sella turcica?

  The sella turcica is a saddle-shaped prominence on the superior surface of the sphenoid body, which houses the hypophyseal fossa for the pituitary gland.
• What does the ethmoid bone contribute to?

  The ethmoid bone forms most of the medial bony area between the nasal cavity and the orbits.
• What does the term "ethmos" mean in Greek?

  It means "sieve" in Greek.
• What is the structure of the ethmoid bone?

  The ethmoid bone is remarkably thin-walled and delicate.
• What is the cribriform plate's function in the ethmoid bone?

  The cribriform plate contributes to the roof of the nasal cavity.
• What are the important markings of the ethmoid bone?

  • Cribriform plate: contributes to the roof of the nasal cavity
  • Perpendicular plate: forms the superior part of the nasal septum
  • Ethmoidal labyrinth: contains the ethmoidal air cells