Anatomy & Physiology Chapter 8 Study Guide (Test 2)

What is the clinical significance of the sternal angle?

It is an important landmark in the costal cartilages of the second ribs attach here; thus, it may be used to count the ribs

Describe kyphosis.

Kyphosis is an exaggerated thoracic curvature that is directed posteriorly, producing a hunchback look. Kyphosis often results from osteoporosis but may also occur due to a vertebral compression fracture, osteomalacia (a disease in which adult bones become demineralized), abnormal vertebral growth, or chronic contraction in muscles that insert on the vertebrae.

Anatomical neck

between the tubercles and the head of the humerus, an almost indistinct groove that marks the location of the former epiphyseal plate

Intertubercular sulcus

between the two tubercles (also called bicipital sulcus or bicipital groove), a depression that contains the tendon of the long head of the biceps brachii muscle

Radial tuberosity

bicipital tuberosity, attachment site for biceps brachii muscle

How many ribs do males and females have?

12

How many vertebrae fuse to form the coccyx? What is the function of the coccyx?

4. It is an attachment site for several ligaments and some muscles.

How many vertebrae compose the sacrum?

5

What is the spinous process?

A spinous process projects posteriorly from the junction of the left and right laminae. Most of these spinous processes can be palpated along the skin of the back.

What is the name for C2? What is its most prominent unique feature? What is the function of this?

Axis. The most prominent feature is the prominent dens. The dens acts as a pivot for the lateral rotation of both the atlas and the skull. This articulation between the atlas and axis, called the atlantoaxial joint, permits us to shake our heads "no". This joint is stabilized by a transverse ligament.

What are they five types of vertebrae?

Cervical, thoracic, lumbar, sacrum, coccyx

What is the common name for the clavicle? What is the basic shape of the clavicle?

Collarbone. It is an elongated S-shaped bone.

What is a superior articular process? Superior articular facet?

Each vertebra has superior and inferior articular processes that originate at the junction between the pedicles and laminae. Each particular process has a smooth surface called an articular facet. The facets on the inferior articular processes of each vertebra articulate with the facets on the superior articular processes of the vertebra immediately inferior to it.

How is the lumbar spine denoted? How many are there? Which are fused and what do they form?

Five lumbar vertebrae (designated L1 - L5) from the inferior concave region ("small") of the back (lumbar region). The fifth lumbar vertebra articulates inferiorly with the first sacral vertebra.

Identify the median sacral crest. What forms this structure?

Formed by the fusion of the spinous processes of individual sacral vertebrae.

What is an intervertebral foramen?

Lateral openings between adjacent vertebrae are the intervertebral foramina. The intervertebral foramina provide a horizontally directed passageway through which spinal nerves extend to various parts of the body.

What is a transverse process?

Lateral projections on both sides of the vertebral arch are called transverse processes.

Describe lordosis.

Lordosis is an exaggerated lumbar curvature, often called swayback, that is seen as a protrusion of the abdomen and buttocks. Lordosis may have the same causes as kyphosis, or it may result from the added abdominal weight associated with pregnancy or obesity.

What feature is found only on the transverse process of cervical vertebrae? What is its function?

Most cervical vertebrae are distinguished from other vertebrae by the presence of transverse foramina in their transverse processes that house the vertebral artery and vein (Sometimes C7 does not have these foramina)

What is the sacroiliac (SI) joint?

On the lateral surface of the ala is the auricular surface, which marks the articulation with the os coxae of the pelvic girdle, forming the sacroiliac joint.

What is the anatomical name for the thumb? How many phalanges are present in the thumb?

Pollex. 2.

What is the vertebral arch? What structures form the vertebral arch?

Posterior to the vertebral body is the vertebral arch, also called the neural arch.

What are some key functions of the thoracic cage?

Protective enclosure around the thoracic organs and provides attachment points for many muscles.

What is the function of the vertebral column?

Provides vertical support for the body and supports the weight of the head. It helps maintain an upright position. Most important, it houses and protects the delicate spinal cord.

What are true ribs? Which are true?

Ribs 1-7 are called true ribs. They articulate directly and individually to the sternum by separate cartilaginous extensions called costal cartilages. Smallest true rib is the first.

What are false ribs? Which are false?

Ribs 8-12 are false ribs because their costal cartilages do not articulate directly to the sternum.

How are the metacarpals named? Note: these are the bones that form the palm of the hand.

Roman numerals I-V with metacarpal 1 located and the base of the thumb and metacarpal V at the base of the little finger

Why are you a little shorter at the end of the day?

because as the day goes on, water in the discs of the spine get compressed (squeezed) due to gravity, making you a tiny bit shorter.

Describe scoliosis.

Scoliosis is the most common spinal curvature deformity. It is an abnormal lateral curvature that sometimes results during development when both the vertebral arch and body fail to form, or form incompletely, on one side of a vertebra. It can also be caused by unilateral muscular paralysis, or spasm, in the back. Mild cases of scoliosis may be treated in adolescence by wearing a back brace, whereas more severe cases may be treated with cervical intervention.

How is the cervical vertebrae denoted? How many are there? Which are fused and what do they form?

Seven cervical vertebrae (designated C1 - C7) form the bones of the neck (cervical region). The first cervical vertebra (C1) articulates superiorly with the occipital condyles of the skull. The seventh cervical vertebra articulates inferiorly with the first thoracic vertebra.

What are the two ends of the clavicle? Which end is flat?

Sternal end, and acromial end. Acromial is flat.

What is the name of the depression on the anterior side of the scapula?

Subscapular fossa.

What are the three sides and the three corners of the scapula called?

Superior, medial, and lateral border. Superior, inferior, and lateral angles.

What is the function of the pectoral girdle? What bones comprise the pectoral girdle?

Supports the upper limbs. Consists of the clavicles and the scapulae.

What is the name of the depression located superior to the spine? Inferior to the spine? Use the names to help you locate these depressions! Note that they are on the posterior side.

Supraspinous. Infraspinous.

What are the spinal curvatures?

The adult vertebral column has four spinal curvatures: the cervical, thoracic, lumbar, and sacral curvatures. This arrangement better supports the weight of the body when standing that could a straight spine.

What is the body of a vertebrae?

The anterior region of each vertebra is a thick, cylindrical body or centrum, which is the weight-bearing structure of each vertebra.

What is the name for C1? What is lacking in this vertebra?

The atlas. It lacks both a body and a spinous process. Instead it has lateral masses that are connected by semicircular anterior and posterior arches, each containing slight protuberances, the anterior and posterior tubercles. The atlas has depressed, oval superior and inferior articular facets that articulate with the occipital condyles and the axis. The atlas has an articular facet for dens on its anterior arch.

What is the vertebral foramen? Vertebral canal? What is located in the vertebral canal?

The body together with the vertebral arch enclose an opening called the vertebral foramen. All the stacked vertebral foramina collectively form a superior-to-inferior directed vertebral canal that contains the spinal cord.

Describe the size and shape of cervical vertebrae.

The cervical vertebrae are the most superiorly located vertebrae. They typically have kidney-bean shaped bodies and extend inferiorly from the occipital bone of the skull through the neck of the thorax. Because cervical vertebrae support only the weight of the head, their vertebral bodies are relatively small and light.

How is the coccyx denoted? How many are there? Which are fused and what do they form?

The coccyx is commonly called the tailbone and is formed from four coccygeal vertebrae (designated Co1 - Co4) that start to unite during puberty and is complete by the mid 20s. The first coccygeal vertebra (Co1) articulates with the inferior end of the sacrum. In much later years, the coccyx also may fuse to the sacrum.

What are floating ribs? Which are floating?

The costal cartilages of ribs 8-10 fuse to the costal cartilage of rib 7 and thus indirectly articulate with the sternum. The last two pairs of false ribs (ribs 11 and 12) are called floating ribs because they have no articulation with the sternum.

What are transverse ridges?

The horizontal lines of fusion that remain after the vertebrae start to fuse shortly after puberty and are usually completely fused between the ages of 20 and 30.

Describe the size and shape of lumbar vertebrae.

The largest vertebrae are the lumbar vertebrae, as they bear most of the weight of the body. A typical lumbar vertebra body is thicker than that of all the other vertebrae, and its body is oval or round. The lumbar vertebrae are distinguished by the features they lack—that is, lumbar vertebrae have neither transverse foramina (like the cervical vertebrae) nor costal facets (like the thoracic vertebrae). The thick spinous processes provide extensive surface area for the attachment of inferior back muscles that reinforce or adjust the lumbar curvature.

In anatomical position, the forearm is supinated and the bones are roughly parallel. What happens when the forearm is pronated?

The palm of the hand is facing posteriorly and the head of the radius is still along the lateral side of the elbow, but the distal end of the radius has crossed over and become a more medial structure

What are the primary spinal curvatures? When do they appear?

The primary curves are the thoracic and sacral curvatures, and they are present at birth. These curvatures arch posteriorly and result in the vertebral column being C-shaped.

What are some functional differences between the upper and lower limbs?

The proximal part of both upper and lower limbs are supported by a girdle of bones; the pectoral girdle (i.e. both ossa coxae) articulates with the lower limb. The proximal part of each limb has one large bone: the humerus in the upper limb and the femur in the lower limb. The distal part of each limb contains two bones; these bones are able to pivot slightly about one another. Both the wrist and proximal foot contain multiple bones (carpal and tarsal bones, respectively) that allow for a range of movement. Finally, the feet and hands are very similar in that they both contain either 5 metacarpals (palm of hand) or 5 metatarsals (arch of foot), and each contains a total of 14 phalanges (bones of fingers and toes, respectively)

What are some structural similarities between the upper and lower limbs?

The proximal part of each limb has a girdle that holds the limb in place. The distal part of each limb contains two long bones, followed by multiple short bones and then numerous long bones in the hand and foot.

How is the sacrum denoted? How many are there? Which are fused and what do they form?

The sacrum is formed from five sacral vertebrae (designated S1 - S5) that fuse into a single bony structure by the mid to late 20s. The sacrum articulates with L5 superiorly, the first coccygeal vertebra inferiorly, and laterally with the two ossa coxae (hip bones).

What are the secondary spinal curvatures? When do they appear?

The secondary curves are called the cervical lumbar curvatures, and they appear after birth. These curvatures arch anteriorly and are also known as the compensation curves because they help shift the trunk weight over the legs. The cervical curvature appears when the child is first able to hold up its head without support (usually around 3-4 months of age). The lumbar curvature appears when the child is learning to stand and walk (typically around the first year of life). These curvatures become accentuated as the child becomes more adept at walking. The sacral curvature is less pronounced in females than in males, to allow for a greater pelvic outlet to accommodate the passage of an infant through the birth canal.

When do the spinal curvatures appear?

The spinal curvatures appear sequentially during fetal, newborn, and child developmental stages.

What is an intervertebral disc? Describe the two components of an intervertebral disc?

The stack of vertebral bodies is stabilized and interconnected by ligaments. Adjacent vertebral bodies are separated by pads of fibrocartilage, called intervertebral discs. Intervertebral discs are composed of an outer ring of fibrocartilage, called the anulus fibrosus, and an inner gelatinous, circular region, called the nucleus pulposus. Intervertebral discs make up approximately one-quarter of the entire vertebral column length.

Which bones comprise the thoracic cage?

The thoracic vertebrae posteriorly, the ribs laterally, and the sternum anteriorly.

Describe the functions of intervertebral discs.

They act as shock absorbers between the vertebral bodies and permit the vertebral column to bend. For example, when you bend your torso anteriorly, the intervertebral discs are compressed at the bending anterior surface and pushed out at the opposite posterior surface.

What are some structural differences between the upper and lower limbs?

They arise from their functional differences. Because the lower limb is weight bearing and is used for locomotion, some mobility at specific joints has been lost for greater stability. The upper limb is not weight bearing, so both arm and forearm bones are relatively smaller and lighter than the similar respective lower limb bones. Additionally, the upper limb joints are relatively more mobile than the respective lower limb joints, so we may utilize the upper limbs for a wide range of activities. Unfortunately, more mobile joints are less stable, and that is why some of the upper limb joints (such as shoulder joints) are the most frequently injured.

Describe the size and shape of thoracic vertebrae.

Thoracic vertebrae typically have heart-shaped bodies and are distinguished from all other types of vertebrae by the presence of costal facets or costal demifacets (semiciruclar faets) on the lateral side of the body and on the sides of the rib articulates with the costal facet of demifacet on the body of the thoracic vertebrae.

What feature is found only on the spinous process of some cervical vertebrae?

Transverse foramina

How is the thoracic vertebrae denoted? How many are there? Which are fused and what do they form?

Twelve thoracic vertebrae (designated T1 - T12) from the superior region of the back (thoracic region). Each thoracic vertebra articulates laterally with one or two pairs of ribs. The twelfth thoracic vertebra articulates inferiorly with the first lumbar vertebra.

What is the name for C7? Why?

Vertebra prominens. It represents a transition from cervical to the thoracic region. The spinous processes of both C7 and all the thoracic vertebrae are nonbifid (not forked) however, the process in C7 is much longer than it is within the other cervical vertebrae. It is easily palpated through the skin between the shoulder blades and inferior to the neck, thus its name.

Radial notch

articulates with head of radius

Head of ulna

at distal end of ulna, shaft narrows and terminates in a knoblike head that has a posteromedial styloid process

Lateral epicondyle

bony side projections on the distal humerus that provides surfaces for muscle attachment.

medial epicondyle of humerus

bony side projections on the distal humerus that provides surfaces for muscle attachment.

Syloid process of ulna

bump on the posteromedial side of head at ulna

Shaft of radius

curves slightly and leads to wider distal end

Radial fossa

depression that accommodates the head of the radius

Coronoid fossa

depression that is anteromedially placed and accommodates the coronoid process of the ulna

Where does the head of the humerus articulate?

glenoid cavity

Coronoid process

inferior lip of trochlear notch, articulates with humerus at the coronoid process

Syloid process of radius

laterally placed, bony projection on the lateral side of wrist, just proximal to the thumb

Shaft of humerus

length of humerus

Ulnar notch

medial surface of radius, articulates with the medial surface of the distal end of the ulna at the distal radioulnar joint

Neck of humerus

narrow, extends from the radial head to radial tuberosity

Surgical neck

narrowing of the bone immediately distal to the tubercles, at the transition from the head to the shaft. Called this because it is a common fracture site.

Greater tubercle

positioned lateral to the head and helps form the rounded contour of the shoulder

Olecranon fossa

posterior depression that accommodates the olecranon of the ulna when the elbow is extended

The spine of the scapula is on the _________ side and can be easily palpated. The spine is continuous with a process called the _____________. This forms the point of the shoulder. A smaller, more anterior process called the _____________ _______________ is a point of muscle attachment.

posterior, acromion, coracoid process

Trochlear notch

proximal end of ulna, C-shaped, interlocks with the trochlea of the humerus

Head of humerus

proximal end that articulates with glenoid cavity of the scapula

Head of radius

proximal end, disc shaped, articulates with capitulum of humerus

Trochlea

pulley shaped, is located medially and articulates with the trochlear notch of the ulna.

The ________ is on the pollex (thumb) side and the ________ is on the little (pinky) finger side

radius, ulna

Thoracic vertebrae articulate with __________ and have some unique features because of that, including ________ _________ and __________ _____________(semicircular facets).

ribs, costal facets, costal demifacets

Deltoid tuberosity

roughened area on the shaft which extends along its lateral surface for about half the length of the humerus

capitulum of humerus

rounded, located laterally and articulates with the head of the radius

Lesser tubercle

smaller and located more medial to the head.

Olecranon

the posterosuperior aspect of the trochlear notch, prominent projection, articulates with the olecranon fossa of the humerus and forms the posterior bump of elbow