Human Anatomy: Head and Neck Muscles

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Questions and Answers

Which scalene muscle is primarily responsible for lateral flexion of the neck?

Levator scapulae

Anterior scalene

Middle scalene (correct)

Posterior scalene

Which group of muscles is involved in neck extension?

Superficial group (SCM)

Prevertebral group

Scalenes

Suboccipital group (correct)

Which muscle is primarily responsible for neck flexion?

Sternocleidomastoid (correct)

Longus colli

Platysma

Digastric

The deep posterior neck muscles include which of the following?

Semispinalis capitis Signup and view all the answers

What is the primary function of the suprahyoid muscles?

Elevate the hyoid and depress the mandible Signup and view all the answers

Which scalene muscle assists in stabilization of the frontal plane?

Anterior scalene Signup and view all the answers

Which muscle is classified as an infrahyoid muscle?

Sternothyroid Signup and view all the answers

Which muscle action is NOT performed by the splenius group?

Flexion Signup and view all the answers

Which of the following muscles is located superficial to the suboccipital group?

Semispinalis cervicis Signup and view all the answers

What are the two bellies of the digastric muscle?

Anterior and posterior Signup and view all the answers

What is the function of the anterior scalene muscle?

Lateral flexion Signup and view all the answers

The prevertebral muscles are located anterior to which structures?

Vertebral bodies Signup and view all the answers

Which of the following is NOT a muscle group found in the neck?

Hypoglossal muscles Signup and view all the answers

Which of the following muscles contributes to ipsilateral rotation of the neck?

Splenius capitis Signup and view all the answers

Which function is associated with the platysma muscle?

Facial expression Signup and view all the answers

Which nerve innervates the palatoglossus muscle?

Vagus nerve (CN X) Signup and view all the answers

What is a common feature shared by all vertebrae?

Spinous process Signup and view all the answers

Which cervical vertebra is characterized by having no body?

C1 - Atlas Signup and view all the answers

What structure does the C2 vertebra, known as the Axis, possess that is significant in its anatomy?

Dens Signup and view all the answers

Which term describes the bony projection that typically facilitates articulation with adjacent vertebrae?

Articular facets Signup and view all the answers

What distinguishes cervical vertebrae from other types of vertebrae?

Bifid spinous process Signup and view all the answers

Which part of a vertebra forms the central opening through which the spinal cord passes?

Vertebral foramen Signup and view all the answers

How many cervical vertebrae are there in the human body?

7 Signup and view all the answers

What is a primary function of the transverse foramina found in cervical vertebrae?

Passage of vertebral arteries Signup and view all the answers

What is the primary function of costal facets on thoracic vertebrae?

They are articular sites for ribs. Signup and view all the answers

Which vertebrae have mammillary processes that provide attachment for deep back muscles?

Lumbar vertebrae Signup and view all the answers

What distinguishes the sacrum in terms of its structure?

It is formed by 5 fused sacral vertebrae. Signup and view all the answers

Which part of the lumbar vertebrae is specifically associated with muscle attachment?

Mammillary processes Signup and view all the answers

In the thoracic vertebrae, where are the inferior costal facets located?

On the body of the vertebrae Signup and view all the answers

Which of the following structures is NOT associated with the sacrum?

Spinous processes Signup and view all the answers

What is the role of the posterior and anterior sacral foramina?

Allowing passage for spinal nerves Signup and view all the answers

Which vertebral group articulates directly with ribs?

Thoracic vertebrae Signup and view all the answers

What is the main function of the intervertebral discs?

To absorb shock and provide deformability Signup and view all the answers

Which region of the vertebral column consists of primary curvatures?

Thoracic and sacral regions Signup and view all the answers

What type of joint is found between the bodies of adjacent vertebrae?

Intervertebral symphysis Signup and view all the answers

Which vertebral joint permits gliding movements but limits flexion and extension?

Zygapophyseal joints Signup and view all the answers

What characteristic is true about the nucleus pulposus of an intervertebral disc?

It has a gelatinous consistency Signup and view all the answers

How many fused coccygeal vertebrae are typically found in adults?

4 Signup and view all the answers

Which of the following describes the lordosis curvature?

Anteriorly concave curvature in the lumbar region Signup and view all the answers

What structure is located on the lateral aspect of the sacrum?

Auricular surface Signup and view all the answers

Study Notes

Superficial muscles

The platysma muscle is a muscle of facial expression.
The sternocleidomastoid is the primary neck flexor.

Suprahyoid muscles

Suprahyoid muscles attach to the hyoid bone from above the hyoid bone.
Suprahyoid muscles elevate the hyoid bone, depress the mandible, and act on the floor of the oral cavity.
Suprahyoid muscles include the digastric, stylohoid, mylohyoid, and geniohyoid muscles.
The digastric has both anterior and posterior bellies.

Infrahyoid muscles

Infrahyoid muscles attach to the hyoid bone from below the hyoid bone.
Infrahyoid muscles depress the hyoid bone and act on the larynx.
Infrayoid muscles include the omohyoid, sternohyoid, sternothyroid, and thyrohyoid muscles.
The omohyoid has both superior and interior bellies.

Prevertebral muscles

Prevertebral muscles are deep muscles located immediately anterior to the vertebral bodies.
Prevertebral muscles include the longus capitis, longus colli, rectus capitis anterior, and rectus capitis lateralis.

Muscles of the lateral neck

The lateral neck contains three scalene muscles: anterior scalene, middle scalene, and posterior scalene.
The scalene muscles produce lateral flexion with ipsilateral action (same side of the body).
The scalenes also stabilize in the frontal plane with bilateral action (both sides of the body).

Muscles in the posterior neck

Muscles in the posterior neck extend the neck, including the trapezius, levator scapulae, splenius capitis/cervicis, semispenalis capitis/cervicis, and longissimus capitis/cervicis.
These muscles also perform lateral flexion and rotation.

Suboccipital Muscles

The suboccipital muscles are the deepest posterior neck muscles.
The suboccipital muscles include the rectus capitis posterior major, rectus capitis posterior minor, obliquus capitis superior, and obliquus capitis inferior.

Summary of Muscle Actions in the Neck

The muscles of the neck can be categorized depending on the plane of action.
Action in the median plane includes flexion and extension.
Action in the transverse plane includes ipsilateral and contralateral rotation.
Action in the frontal plane includes lateral flexion.

Vertebrae

All vertebrae are irregular bones sharing common features: body, transverse processes, spinous process, vertebral arch, vertebral foramen, and articular facets.
The vertebral arch is composed of the lamina and the pedicle.
Vertebral foramen is the hole in the center of the vertebra.
Articular facets are the small, flat surfaces that connect the vertebrae together.

Cervical Vertebrae

Cervical vertebrae contain transverse foramina and bifid spinous processes.
The atlas (C1) has no body.
The axis (C2) has a dens.
The seventh cervical vertebra (C7) has a larger, non-bifid spinous process and the vertebral prominence.

Thoracic Vertebrae

The thoracic vertebrae are characterized by costal facets which articulate with ribs.
Each of the 12 thoracic vertebrae has superior, inferior, and transverse costal facets.

Lumbar Vertebrae

Lumbar vertebrae are the largest vertebrae.
Lumbar vertebrae contain mammillary processes which provide attachment sites for deep back muscles.

Sacrum & Coccyx

The sacrum is composed of five fused sacral vertebrae.
The sacrum contains lateral, intermediate, and medial crests, anterior and posterior sacral foramina, a sacral hiatus, a sacral horn, an ala, and an auricular surface.
The coccyx is composed of four fused coccygeal vertebrae.
The coccyx contains a coccygeal horn.

Vertebral Column

The vertebral column has 33 stacked vertebrae.
The cervical vertebrae are the seven most superior vertebrae.
The thoracic vertebrae are the 12 vertebrae that connect to the ribs.
The lumbar vertebrae are the five vertebrae located in the lower back.
The sacrum is composed of five fused vertebrae.
The coccyx is composed of four fused vertebrae.
The vertebral column functions to supports body weight and provides bony protection for the spinal cord.

Curvatures

The curves of the vertebral column aid in weight distribution, shock absorption, and stability.
The thoracic and sacral regions of the vertebral column are concave anteriorly.
The cervical and lumbar regions of the vertebral column are concave posteriorly.
The thoracic and sacral curves are called kyphoses.
The cervical and lumbar curves are called lordoses.

Intervertebral Joints

The vertebral column is connected by intervertebral joints, which are categorized as intervertebral symphyses, zygapophyseal joints, atlantoaxial joints, and atlanto-occipital joints.

Intervertebral Symphyses

Intervertebral symphyses connect the bodies of adjacent vertebrae.
Intervertebral symphyses are characterized by the presence of an intervertebral disc, which is composed of the anulus fibrosus (outer fibrocartilage ring) and the nucleus pulposus (gelatinous central mass).

Zygapophyseal Joints

Zygapophyseal joints are also known as facet joints.
Zygapophyseal joints connect the superior and inferior articular facets of adjacent vertebrae.
Zygapophyseal joints permit gliding moments but limit flexion and extension of the neck.

Atlantoaxial Joints

The atlantoaxial joint is between C1 and C2.

Atlanto-occipital Joints

The atlanto-occipital joint is between C1 and the occipital bone.

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Description

This quiz covers the superficial, suprahyoid, infrahyoid, and prevertebral muscles of the head and neck. Test your knowledge on muscle functions, attachments, and classifications, including key muscles such as the sternocleidomastoid and digastric. Perfect for anatomy students seeking to reinforce their understanding.