ANATOMICAL STRUCTURE OF VERTEBRAL COLUMN

• RIBS: Long or short skeletal structures.

  ● Laid down first as cartilaginous models.

  ● Proximal ends of ribs are like vertebrae.

  
• RIBS

  RIB Functions:

  ● Protection – caged vitals organs such as the heart and lungs.

  ● Structure and support – stability and shape of the thoracic region.

  ● Respiration – rib cage expands when inhaling.

  ● Attachment – for muscles involved in respiration, posture, and movement.
• RIBS:

  • True ribs – attached directly to the sternum.
  • False ribs – do not have direct attachment to the

  sternum.

  • Floating ribs – do not attach to the sternum at all.

  A) TRUE RIBS

  B) FALSE RIBS

  C) FLOATING RIBS

  
• Ribs of different vertebrate groups

  FISHES:

  ● ribs on every trunk vertebra and anterior caudals as well.

  ● Polypterus and some teleosts (salmon, herring, pike) exhibit two ribs on each side.

  ● A dorsal rib passes laterad in the horizontal septum.

  ● A ventral rib arches ventrad in the body wall.

  
• Ribs of different vertebrate group

  AMPHIBIA:

  ● More reduced than those of other tetrapods.

  ● The ribs do not reach the sternum.

  ● All the ribs of anurans and urodeles have become very short. (ankylosed process)

  ● the ribs of the limbless, burrow dwelling apodans are quite long.

  A) ATLAS

  B) NEURAL P

  C) PARASAGITAL P

  D) TRANSVERSE P

  E) SESAMOID

  F) SACRAL DIAPOPHYSIS

  G) DORSAL CREST OF UROSTYLE

  H) UROSTYLE

  
• Ribs of different vertebrate group


  REPTILIA:

  ● Lizards and crocodilians have long ribs on the

  trunk vertebrae and short ribs in the neck.

  ● Turtles have no cervical ribs.

  ● Snakes have long, curved ribs.

  
• Ribs of different vertebrate groups

  AVES

  ● The first two pairs of ribs in many carinates articulate with the last two cervical vertebrae at the base of the neck. ● The next five pairs are thoracic ribs with bony sternal segments. Thoracic ribs constitute the major skeleton of the thoracic basket (chest cavity)

  
• Ribs of different vertebrate groups

  MAMMALIA

  ● Recognizable ribs in mammals are generally confined to the thorax.

  ● The costal cartilages fail to reach the sternum.

  ● two heads of a vestigial bicipital rib develop in association with each cervical vertebra.

  
• STERNUM

  ● Exclusive tetrapod structure

  ● The sternum (or breastbone) is a flat bone located at the anterior aspect of the thorax.

  A) STERNUM

  
• STERNUM


  Functions:

  • RESPIRATION - facilitates movements during breathing.
  • STRUCTURE & SUPPORT - provides structural support to the thoracic cavity.
  • PROTECTION - helps protect the internal thoracic viscera- such as the heart, lungs, and esophagus.
• STRUCTURE OF STERNUM

  STRUCTURE OF A TYPICAL STERNUM

  ● MANUBRIUM - roughly trapezoidal in shape and articulates with the clavicles (collarbones) laterally and the first two pairs of ribs inferiorly.

  ● XIPHISTERNUM - thin, cartilaginous structure that ossifies with age.

  A) MANUBRIUM

  B) BODY

  C) XIPHOID PROCESS

  
• DEVELOPMENT OF THE STERNUM

  DEVELOPMENT OF THE STERNUM

  ● arises in embryos of reptiles, birds, and mammals as a pair of mesenchymal sternal bars at the anterior ends.

  ● sternal bars eventually unite in the midline to form a

  cartilaginous model.

  ● presternal blastema contributes to the manubrium

  A) SUPRASTERNAL BLASTEMA

  B) STERNAL RIB

  C) STERNAL BAR

  D) PRESTERNAL BLESTEMA

  
• STERNA OF DIFFERENT VERTEBRATE GROUPS

  STERNA OF DIFFERENT VERTEBRATE GROUPS

  A)

  
• AMPHIBIA

  AMPHIBIA

  ● Amphibians lack a well-defined sternum like that seen in mammals and birds

  A) STERNUM

  B) EPISTERNUM

  C) OMOSTERNUM

  D) STERNUM

  E) XIPHISTERNUM

  
• STERNA OF DIFFERENT VERTEBRATE GROUPS


  REPTILIA

  ● Consists of a cartilaginous plate.

  ● Snakes, legless lizards, and turtles have no sternum.

  A) PROCORACOID

  B) RIBS

  C) XIPHISTERNUM

  
• STERNA OF DIFFERENT VERTEBRATE GROUPS

  AVES

  ● Large bony element articulating with numerous ribs.

  ● Carinate birds: In birds with strong muscles for flight, the sternum exhibits a midventral keel, the carina, for insertion of the muscles.

  A) PROCORACOID

  B) RIBS

  C) XIPHISTERNUM

  D) CARINA

  E) PROCORACOID

  F) CLAVICLE

  
• STERNA OF DIFFERENT VERTEBRATE GROUPS

  MAMMALIA

  ● elongated bony rod usually composed of a series of segments (sternebrae).

  A) CLAVICLE

  B) MANUBRIUM

  C) XIPHISTERNUM

  D) XIPHOID PROCESS