Axial Muscles

The internal oblique muscles are responsible for compressing the abdomen and rotating the trunk. This action helps in forced expiration, defecation, urination, and parturition. These muscles work together with other muscles in the abdominal region to generate the necessary force for these actions.

The correct answer is xiphoid process of sternum & linea alba. The transverse abdominus muscle inserts into the xiphoid process of the sternum and the linea alba. The xiphoid process is a small, cartilaginous extension at the bottom of the sternum, while the linea alba is a fibrous band that runs vertically down the midline of the abdomen. These insertions allow the transverse abdominus to help stabilize the trunk and compress the abdominal contents.

The frontalis muscle is responsible for raising the eyebrows and wrinkling the forehead. This action is commonly associated with expressions of surprise or concern.

The zygomatic arch is the correct answer because it is the only structure listed that is directly related to the zygomaticus muscle. The zygomaticus muscle is responsible for elevating the corners of the mouth and is attached to the zygomatic arch. The other structures listed, such as the epicranial aponeuroses, ligamentum nuchae, and spinous process of vertebrae C7-T4, are not directly associated with the zygomaticus muscle.

Zygomaticus action refers to the muscle that pulls the corner of the mouth upward and outward. This muscle is responsible for smiling and expressing happiness. It contracts when we smile, causing the corners of the mouth to lift and create a smiling expression.

The sternocleidomastoid muscle originates from the manubrium of the sternum and the medial clavicle. This means that it attaches to and starts from these two structures. The ligamentum nuchae, spinous process of vertebrae C7-T4, and epicranial aponeurosis are not the origins of the sternocleidomastoid muscle.

The external oblique muscles are located on the sides of the abdomen. When they contract, they compress the abdomen, which can help with forced expiration, defecation, urination, and parturition (the process of giving birth). Additionally, the external oblique muscles also contribute to the rotation of the trunk, allowing for twisting movements. However, there is no mention of the external oblique muscles abducting the humerus or flexing the leg, so these actions are not associated with this muscle.

The external oblique muscle inserts into the iliac crest of the ilium, pubis, and linea alba. This means that the muscle attaches to these structures. The iliac crest is the upper border of the hip bone, the ilium. The pubis is the front part of the hip bone, and the linea alba is a fibrous band that runs vertically down the midline of the abdomen. The insertion of the external oblique muscle into these structures allows it to play a role in flexing and rotating the trunk, as well as compressing the abdomen.

The internal oblique muscle is innervated by the ventral rami of spinal nerves T7-T12. These nerves originate from the spinal cord and branch out to supply various muscles and areas of the body. In the case of the internal oblique muscle, the ventral rami of spinal nerves T7-T12 provide the necessary motor innervation for its contraction and movement.

The correct answer is "cartilage of ribs 9-12, linea alba." The internal oblique muscle originates from the iliac crest, inguinal ligament, and thoracolumbar fascia. It inserts into the cartilage of ribs 9-12 and the linea alba. This means that the muscle is attached to the lower ribs and the connective tissue in the midline of the abdomen. The other options mentioned, such as the deltoid tuberosity and the fossa below the spine of the scapula, are not relevant to the insertion of the internal oblique muscle.

The external oblique muscle is innervated by the ventral rami of spinal nerves T7-T12. These nerves originate from the thoracic region of the spinal cord and provide motor and sensory innervation to various muscles and skin in the abdominal and thoracic regions. The radial nerve, axillary nerve, and lower scapular nerve are not involved in the innervation of the external oblique muscle.

The correct answer is spinous processes of T-7 through S-5, iliac crest of ilium. The latissimus dorsi muscle originates from these two locations. It is responsible for extension, medial rotation, and adduction of the humerus. The other options mentioned, such as the anterior edge of the intertubercular groove of the humerus and the medial 2/3 of the clavicle, sternum, and rib cartilages 1-6, are not the origins of the latissimus dorsi muscle.

The trapezius muscle originates from the occipital bone, ligamentum nuchae, and spinous processes of C-7 through T-12. This means that these are the points where the muscle begins or attaches to. The iliac crest of the ilium and the cartilage of ribs 7-12 are not origins of the trapezius muscle.

The pectoralis major muscle has multiple actions. The upper portion of the muscle is responsible for flexion of the humerus, meaning it brings the arm forward towards the body. The lower portion of the muscle is responsible for extension of the humerus, meaning it moves the arm backward away from the body. The entire muscle is involved in adduction, which means it brings the arm towards the midline of the body, and medial rotation, which means it rotates the arm inward towards the body. The muscle attaches to the lateral edge of the intertubercular groove of the humerus.

The correct answer is epicranial aponeurosis. The frontalis muscle is a muscle of the forehead that helps raise the eyebrows and wrinkle the forehead. The origin of the frontalis muscle is the epicranial aponeurosis, which is a broad, fibrous sheet of tissue that covers the top of the skull. This aponeurosis serves as an attachment site for various muscles, including the frontalis muscle. The other options listed in the question are not correct origins for the frontalis muscle.

The external oblique muscle originates from the anterior surface of ribs 5-12.

The correct answer is "ligamentum nuchae and spinous processes of C7-T4 vertebrae." The splenius capitus muscle originates from the ligamentum nuchae, which is a thick fibrous tissue located in the back of the neck, and the spinous processes of the C7-T4 vertebrae, which are the bony projections that extend from the back of each vertebra. These origins provide attachment points for the muscle and allow it to perform its functions, such as extending and rotating the head and neck.

The correct answer is "extend head and neck, laterally flex and rotate head to the same side." The splenius capitis muscle is responsible for these actions, which involve extending the head and neck, as well as laterally flexing and rotating the head to the same side.

The transverse abdominus muscle originates from the iliac crest of the ilium and the cartilage of ribs 7-12. This means that the muscle starts at the top part of the hip bone (iliac crest) and extends up to the lower ribs.

The frontalis muscle is responsible for raising the eyebrows and wrinkling the forehead. Its insertion point is the skin above the eye, which means that it attaches to and ends at this specific location. This allows the muscle to control the movement and positioning of the eyebrows and forehead in order to express various emotions and gestures.

The rectus abdominis muscle originates from the pubic crest and pubic symphysis. This means that the muscle starts from these two points and attaches to other structures in the body. The other options mentioned, such as the anterior surface of ribs 5-12 and the iliac crest of ilium, are not the correct origins of the rectus abdominis muscle.

The deltoid muscle originates from the lateral 1/3 of the clavicle, the acromion process, and the spine of the scapula. This means that these three points are the starting points or attachments of the muscle. The deltoid tuberosity of the humerus and the inferior medial scapula are not the origins of the deltoid muscle.

The levator scapulae muscle is responsible for two main actions: elevation of the scapula and downward rotation of the scapula. When the muscle contracts, it helps to lift the scapula towards the ears, resulting in elevation. Additionally, it also aids in rotating the scapula downwards, which is important for movements like lowering the shoulder or reaching towards the ground. Therefore, the correct answer is "elevation of scapula, downward rotation of scapula."

The supraspinatus muscle is responsible for initiating the abduction of the humerus. Abduction refers to the movement of the arm away from the midline of the body. The supraspinatus muscle is one of the rotator cuff muscles located in the shoulder, and its contraction helps to lift the arm and initiate the movement of abduction. Therefore, the statement "begins abduction of humerus" accurately describes the action of the supraspinatus muscle.

The correct answer is orbicularis oris. The zygomaticus insertion refers to the point where the zygomaticus muscle attaches to the orbicularis oris muscle. The orbicularis oris muscle is located around the mouth and is responsible for various movements of the lips, such as puckering and smiling. The zygomaticus muscle, on the other hand, extends from the zygomatic bone to the corner of the mouth and is involved in smiling. Therefore, the zygomaticus insertion being the orbicularis oris muscle makes anatomical sense.

The sternocleidomastoid muscle is innervated by the accessory nerve (CN-XI). This nerve originates from the spinal cord and supplies motor fibers to the sternocleidomastoid and trapezius muscles. The dorsal rami of spinal nerves innervate the muscles and skin of the back, not the sternocleidomastoid. The facial nerve (CN-VII) primarily innervates the muscles of facial expression, while the ventral rami of spinal nerves T7-T12 innervate the intercostal muscles and abdominal muscles. Therefore, the correct answer is the accessory nerve (CN-XI).

The teres major muscle originates from the inferior medial scapula.

The correct answer is the mastoid process of the temporal bone. The splenius capitus muscle is a broad, strap-like muscle located at the back of the neck. It originates from the lower half of the ligamentum nuchae and the spinous processes of the vertebrae in the upper back and neck. It inserts into the mastoid process of the temporal bone. This insertion point allows the muscle to assist in extending and rotating the head and neck.

The pectoralis minor muscle inserts onto the coracoid process of the scapula. This means that the muscle attaches to the bony prominence on the scapula called the coracoid process. The coracoid process is located on the anterior (front) side of the scapula.

The infraspinatus muscle is located in the shoulder and is responsible for the lateral rotation of the humerus. This means that when the infraspinatus contracts, it causes the arm to rotate outward away from the body. This action is important for various movements of the shoulder, such as throwing a ball or reaching for an object to the side.

The correct answer is "xiphoid process of sternum & cartilage of ribs 5-7." The rectus abdominis muscle is a paired muscle that runs vertically along the anterior abdominal wall. Its main function is to flex the trunk and compress the abdominal contents. The muscle originates from the pubic symphysis and pubic crest and inserts onto the xiphoid process of the sternum and the cartilage of ribs 5-7. This insertion allows the rectus abdominis to assist in raising the ribs during activities such as forced expiration or coughing.

The gluteus maximus is the largest muscle in the buttocks and is responsible for extending the thigh at the hip joint, meaning it helps to move the leg backward. It also performs lateral rotation of the thigh, which involves rotating the leg away from the midline of the body. Therefore, the correct answer is extension of the thigh and lateral rotation of the thigh.

The correct answer is dorsal rami of spinal nerves. The splenius capitus muscle is innervated by the dorsal rami of spinal nerves, specifically the posterior branches of the upper cervical spinal nerves. These nerves arise from the spinal cord and travel through the vertebral column, branching out to provide sensory and motor innervation to the muscles and skin of the back and neck. Therefore, the dorsal rami of spinal nerves are responsible for innervating the splenius capitus muscle.

The serratus anterior muscle inserts on the medial border of the scapula and the inferior angle of the scapula. This means that the muscle attaches to these specific points on the scapula.

The tensor fascia latae muscle inserts into the iliotibial tract. The iliotibial tract is a thick band of connective tissue that runs down the side of the thigh. It originates from the iliac crest of the ilium and inserts into the lateral condyle of the tibia. The tensor fascia latae muscle plays a role in stabilizing the hip and knee joints and is involved in movements such as hip abduction and medial rotation of the thigh.

The correct answer is the lateral edge of the intertubercular groove of the humerus. The pectoralis major muscle is a large muscle located in the chest area. It originates from the clavicle, sternum, and costal cartilage of the ribs and inserts into the humerus bone. Specifically, it inserts onto the lateral edge of the intertubercular groove of the humerus. This insertion point allows the pectoralis major muscle to contribute to movements of the shoulder joint, such as flexion, adduction, and medial rotation.

The levator scapulae muscle inserts at the superior angle of the scapula.

The correct answer is the transverse processes and bodies of the lumbar vertebrae and the anterior surface of the ilium, as well as the lesser trochanter of the femur. The iliopsoas muscle is a major hip flexor that consists of two muscles, the psoas major and the iliacus. The psoas major originates from the transverse processes and bodies of the lumbar vertebrae, while the iliacus originates from the anterior surface of the ilium. These two muscles merge together and insert onto the lesser trochanter of the femur. This combined action of the iliopsoas muscle allows for flexion of the hip joint.

The deltoid muscle is the muscle forming the rounded contour of the human shoulder. Anatomically, the deltoid muscle appears to be made up of three distinct sets of muscle fibers, namely the

anterior or clavicular part (pars clavicularis)

posterior or scapular part (pars scapularis)

intermediate or acromial part (pars acromialis)