1. The rectus abd ominis covers the anterior abdominal wall Its superior attachm

Question

1. The rectus abd ominis covers the anterior abdominal wall Its superior attachment includes the xiphoid process and 7; its inferior attachment includes the muscle depresses the ribs and flexes the vermphysis and pubic crest (superior or inferior) is the origin, and which is the insertion? Explain. costal cartilages of ribs 5 through vertebral column. Which attachment pubic symphysis and pubic crest. The 2. When the hyoid bone is elevated, the suprahyoid muscles are the agonists. What muscles act as antago nists? Expla The splenius capitis is a deep muscle on the posterior surface of the neck. It is attached to the occipital bone and to spinous processes of cervical and thoracic vertebrae. One of its functions is to extend the head. Use this information to complete the following table Occipital bone Origin of splenius capitis Splenius capitis Insertion of splenius capitis Structure acting as a lever Structure acting as the fulcrum

Explanation / Answer

Ans 1. The rectus abdominis has its origin along the superior edge of the pubic bone and the pubic symphysis in the pelvis. Its insertions are at the coastal cartilages of the fifth through seventh ribs and at the xiphoid of the sternum. Between the rectus abdominis muscle is the thick mass of white fibrous connective tissue called the Linea Alba that Unites the abdominal muscles of the left and right sides. The main action of rectus abdominis is flexion of spine.

Thus the inferior attachment is region and superior attachment is the insertion.

2. Suprahyoid muscles pull the hyoid bone upward and forward towards the mandible where as the infrahyoid muscles return the Hyoid bone and larynx back to their normal inferior position. Thus infrahyoid muscles act as antagonist.

3. Splenius capitis-

Origin- nuchal ligament and spinous process of C7 to T3.

Insertion- mastoid process of temporal and occipital bone.

Structure acting as lever- Head resting on the vertebral column.

This forms example of first class lever in the body where fulcrum is between the effort and load. Contraction of posterior neck muscles provide the effort. Joint between the Atlas and occipital bone forms fulcrum and weight of entire portion of Skull is load.

Structure acting as fulcrum- Atlantoccipital joint.

32. The contralateral external and internal obliques of right side are the antagonists for lateral flexion of vertebral column to the left side.

33. Both deep back muscles and abdominal muscles strength and flexibility are essential to maintaining the neutral spine position. weak abdominal muscles cause hip flexor muscles to tighten causing an increase in the curve of the low back (lordosis). Thus affecting your posture and can lead to back pain problems.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.