Question

which bone does not help form the orbit?
lacrimal
parietal
sphenoid
frontal
question 13
identify the bones of the thoracic cage: sternum
image of ribcage with labels a, b, c, e, f

Explanation:

First Question (Which bone does NOT help form the orbit?):

The orbit (eye socket) is formed by several bones including the lacrimal, sphenoid, and frontal bones. The parietal bone is part of the skull's roof and sides, not involved in orbit formation.

Answer:

B. parietal

Second Question (Identify the bones of the thoracic cage: sternum and the labeled parts):

Assuming the diagram labels:

• A: Cervical vertebrae (not part of thoracic cage)
• B: Ribs (part of thoracic cage)
• E: Manubrium (part of sternum, thoracic cage)
• F: Body of sternum (part of sternum, thoracic cage)
• C: Costal cartilage (part of rib structure, thoracic cage)

The thoracic cage consists of the sternum (manubrium, body, xiphoid process - though xiphoid not labeled here), ribs, and thoracic vertebrae. From the labels: B (ribs), E (manubrium), F (body of sternum), C (costal cartilage) are part of the thoracic cage. A is cervical vertebrae, not part. But since the question starts with "Identify the bones of the thoracic cage: sternum" and the diagram has labels, if we assume the task is to identify which labeled part is sternum - E and F are parts of the sternum (E likely manubrium, F body). If the question is to identify bones (sternum and ribs etc.), the sternum's parts (E, F) and ribs (B) are part of it.

But based on the diagram:

• E and F are parts of the sternum (thoracic cage bone).
• B is a rib (thoracic cage bone).
• C is costal cartilage (connects rib to sternum, part of thoracic cage structure).
• A is cervical vertebra (not thoracic cage).

If the question is to identify which label is sternum, E and F are sternum (E: manubrium, F: body). If it's to list bones, sternum (E, F), ribs (B), and thoracic vertebrae (not labeled here) are part of the thoracic cage.

Since the question says "Identify the bones of the thoracic cage: sternum" and the diagram has E and F as sternum parts, B as rib, C as costal cartilage. So the sternum is labeled E (manubrium) and F (body), and ribs (B) are also part.

But to answer based on the diagram:
If we take the labels:

• E: Manubrium (part of sternum, thoracic cage)
• F: Body of sternum (part of sternum, thoracic cage)
• B: Rib (part of thoracic cage)
• C: Costal cartilage (part of thoracic cage)
• A: Cervical vertebra (not thoracic cage)

So the bones of the thoracic cage include the sternum (E, F), ribs (B), and thoracic vertebrae (not shown). If the question is to identify which label is sternum, E and F are sternum. If it's to list, sternum (E, F), ribs (B), etc.

But since the question starts with "Identify the bones of the thoracic cage: sternum" and the diagram has E and F pointing to sternum, B to rib, C to costal cartilage, A to cervical vertebra. So the sternum is labeled E (manubrium) and F (body), and ribs (B) are part of the thoracic cage.

(Note: If more specific, the thoracic cage bones are sternum (manubrium, body, xiphoid), 12 pairs of ribs, and 12 thoracic vertebrae. From the diagram, E is manubrium, F is body of sternum, B is a rib, C is costal cartilage (not bone, but connective tissue), A is cervical vertebra (not thoracic). So the bones are sternum (E, F) and ribs (B), along with thoracic vertebrae (not labeled).)