Chapter 8
selected features and their functions
Horizontal plate: Forms posterior part of hard palate Perpendicular plate: Forms part of nasal cavity and orbit
Sulcus
Narrow groove
spinous procesess
Slender c2-c6 are often bifid ( c1 has no spinous process)
superciliary arches
female; littel or no promience male; more prominent and bulky
body shape
kidney bean shapped
Crest
narrow, prominent, ridge-like projection
squamous suture
on each side of the skull is the site where the temporal bone and the parietal bone of that side articulate. The squamous part of the temporal bone typically overlaps the parietal bone.
greater and lesser palatine foramina
palatine bone; palatine vessels, greater and lesser palatine nereves
foramen lacerum
extends between the occpital and temporal bones. this opening covered by cartilage in the living indivudal.
seven cervical vertebrae
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.
Facial bones
form the face.They also protect the entrences to digestive and respiratory systems. Touch your cheeks, you jawas, and the bridge of your nose. these bones are facial bones. The facial bones give shape and individuality to the face, form part of the orbit and nasal cavities support the teeth and provide for the attachment of muscles involved in the facial expressions and mastication. There are 14 facial bones including the paired zygomatic bones, lacrimal bones, nasal bones, inferior nasal conchae, palatine bones, maxillae and unpaired vomer and mandible.
palatine process of the mazillae and the palatine
form the hard palate, which acts as both the floor of the nasal cavity and a portion of the roof of the mouth
five lumbar vertebrae
form the inferior concave region ("small") of the back (lumbar region). The fifth lumbar vertebra articulates inferiorly with the first sacral vertebra.
Trochanter
massive, rough projection found only on the femur
spine
pointed, slender process
superior orbital fissure
posterior part of orbit between greater and lesser wings of sphenoid bone; ophthalmic veins, oculomotor nerve, trochlear nerve, ophthalmic branch of trigeminal nerve, abducens nerve
incisive foramen
posterior to incisor teeth in hard palate of the maxilla; Nasopalatine nerve
Mastoid foramen
posterior to mastoid process of temporal bone; mastoid emissary veins
optic canal
posteromedial part of orbit in lesse wing of sphenoid bone; optic nerves
transverse foramina
present ( exceot sometimes for C7)
costal facets for ribs
present on the body and transverse processes
Xiphoid process of sternum
process represents the very tip of the sword. This small, inferiorly pointed, cartilaginous projection often doesn't ossify until after age 40.
Epicondyle
projection adjacent to a condyle
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. Lateral projections on both sides of the vertebral arch are called transverse processes.
head
prominent, rounded epiphysis
foramen
rounded passageway through a bone
describe the phalanges and their relative locations
A total of 14 bones are present in the digits; these are called phalanges (fă-lan′jēz; sing., phalanx, fā′langks; line of soldiers). Page 281Three phalanges are found in each of the second through fifth fingers, but only two phalanges are present within the thumb, also known as the pollex (pol′eks; thumb). The proximal phalanx articulates with the head of a metacarpal, whereas the distal phalanx is the bone in the very tip of the finger. The middle phalanx of each finger lies between the proximal and distal phalanges; however, a middle phalanx is not present in the pollex.
jugular foramen
Between the temproal bone and occpital bone (posterior to carotid canal) ; internal jugular vein; glossopharyneal nerve, vagus nerve, accessory nerve
saggital suture
separates the left and right parietal bone
supraorbital foramen or notch
supraorbital margin of orbit in frontal bone; supraorbital artery, supraorbital nerve
lambdoid suture
the articulation of the occipital bone with the parietal bones
lacrimal
the bone that articulates with the maxilla anteriorly and witht he elmoid bone posteriorly.
name the three bones that make up each os coxae
the ilium, ischium, and pubis
Frontal sinus and sphenoidal sinus
Vessel impressions may be visible on the internal surface of the skull. The frontal sinus (a space within the frontal bone) and the sphenoidal sinus (open space within the sphenoid bone) are visible in a sagittal view.
parietal foramen
which serves as the passageway of small veins between the brain and the scalp. Its along the posterior on third of the saggital suture
stylomastoid foramen
between mastoid and styloid processes of temporal bone; facial nerve
foramen lacerum
between the petrous part of temporal bone, sphenoid bone and occipital bone, it has no structures that pass through
opening and spaces
canal, fissure, foramen, meatus, sinus
interal acoustic meatus
(also called the internal auditory canal) opens in the more medial portion of the temporal bone and contains the facial nerve (CN VII) and the vestibulocochlear nerve (CN VII
Articulating surfaces
A joint or articulation (or articular surface) is the connection made between bones in the body which link the skeletal system into a functional whole. They are constructed to allow for different degrees and types of movement.
lateral view of skull
A lateral view of the skull (figure 8.6) shows one parietal bone, temporal bone, and zygomatic (zī′gō-mat′ik; zygoma = a joining, a yoke) bone. This view also shows part of the maxilla, mandible, frontal bone, and occipital bone. Page 249The superior and inferior temporal lines arc across the surface of the parietal and frontal bones and mark the attachment site of the temporalis muscle
intervertebral discs
Adjacent vertebral bodies are separated by pads of fibrocartilage, called the intervertebral (in-ter-ver′te-brăl) discs. Intervertebral discs are composed of an outer ring of fibrocartilage, called the anulus fibrosus (an′ū-lŭs fī-brō′sus), and an inner gelatinous, circular region, called the nucleus pulposus
selected features and their functions
Ala: Articulates with sphenoid bone Vertical plate: Articulates with perpendicular plate of ethmoid bone
vertebrate canal
All the stacked vertebral foramina collectively form a superior-to-inferior directed vertebral canal that contains the spinal cord.
selected features and their functions
Alveolar process: Houses the teeth Angle of the mandible:Junction between the body and ramus Body: Horizontal portion of mandible Condylar (kon′di-lăr) process: Posterior projection off ramus; contains head of mandible Coronoid (kōr′ŏ-noyd; korone = a crow) process:Anterior projection off ramus Head of mandible:Articulates with temporal bone Mandibular notch: U-shaped depression between coronoid and condylar processes Mental protuberance:Forms the chin Ramus (rā′mŭs): Vertical portion of mandible
selected fetures and their functions
Anterior nasal spine:Anterior projection formed by union of left and right maxillae Alveolar process:Houses the teeth Frontal process:Forms part of lateral aspect of the nasal bridge Infraorbital margin:Forms inferolateral border of orbit Maxillary sinus:Lightens bone Orbital surface:Forms part of orbit Palatine process:Forms most of bony palate Zygomatic process:Articulates with zygomatic bone
list the landmarks and features of the humerus
Between the tubercles and the head of the humerus is the anatomical neck, an almost indistinct groove that marks the location of the former epiphyseal plate. The surgical neck is a narrowing of the bone immediately distal to the tubercles, at the transition from the head to the shaft. This feature is called the "surgical" neck because it is a common fracture site. The shaft of the humerus has a roughened area, termed the deltoid (del′toyd; deltoides = like the Greek letter Δ)tuberosity (tū′bĕr-os′i-tē), which extends along its lateral surface for about half the length of the humerus. The deltoid muscle of the shoulder attaches to this roughened surface (see section 11.8b). The radial groove (or spiral groove) is located adjacent to the deltoid tuberosity and is the location of the radial nerve (see section 14.5e) and some blood vessels. Together, the bones of the humerus, radius, and ulna form the elbow joint (figure 8.25c). The medial and lateral epicondyles (ep-i-kon′dīl; epi = upon, kondylos = a knuckle) are bony side projections on the distal humerus that provide surfaces for muscle attachment. Palpate the sides of your elbow; the bumps you feel are the medial and lateral epicondyles. Placed posterior to the medial epicondyle is the ulnar nerve (see table 14.4 and section 14.5e). (You actually are hitting this nerve when you hit your funny bone.) The distal end of the humerus has two smooth, curved surfaces for articulation with the bones of the forearm. The rounded capitulum (kă-pit′yū-lŭm; caput = head) is located laterally and articulates with the head of the radius. The pulley-shaped trochlea (trok′lē-ă; trochileia = a pulley) is located medially and articulates with the trochlear notch of the ulna. Additionally, the distal end of the humerus exhibits three depressions, two on its anterior surface and one on its posterior surface. The anterolaterally placed radial fossaaccommodates the head of the radius; the anteromedially placed coronoid (kōr′ŏ-noyd; korone = a crow, eidos = resembling) fossa accommodates the coronoid process of the ulna. The posterior depression, Page 279called the olecranon (ō-lek′ră-non; olene = ulna) fossa, accommodates the olecranon of the ulna when the elbow is extended (i.e., straightened).
differentiate between true ribs and false ribs
Both males and females have 12 pairs of ribs. Ribs 1-7 are called true ribs. True ribs articulate directly and individually to the sternum by separate cartilaginous extensions called costal (kos′tal; costa = rib) cartilages Ribs 8-12 are called false ribs because their costal cartilages do not articulate directly to the sternum. 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.
compare ula and radius
Both the radius and the ulna exhibit interosseous borders, which face each other; the ulna's interosseous border faces laterally, whereas the interosseous border on the radius faces medially. These interosseous borders are connected by an interosseous membrane (interosseous ligament) composed of dense regular connective tissue. This membrane helps keep the radius and ulna a fixed distance apart from one another and provides a pivot of rotation for the forearm. The bony joints that move during this rotation are the proximal and distal radioulnar joints.
selected features and their functions
Cribriform plate:Contains cribriform foramina for passageway of olfactory nerves (CN I) Crista galli:Attachment site for cranial dural septa to help stabilize brain within the skull Ethmoidal labyrinths:Contain ethmoidal sinuses and nasal conchae Ethmoidal sinuses (cells):Lighten bone, moisten inhaled air, and give resonance to voice Nasal conchae (superior and middle): Increase airflow turbulence through nasal cavity so air can be adequately moistened and cleaned by nasal mucosa Orbital plate:Forms part of medial wall of orbit Perpendicular plate: Forms superior part of nasal septum Page 25
description and bounderies of bone
Curved bone that projects medially from lateral walls of the nasal cavity
sagittal sectional view
Cutting the skull along a sagittal sectional plane reveals bones that form the endocranium and the nasal cavity Features such as the perpendicular plate of the ethmoid bone, the vomer, and the frontal and sphenoidal sinuses, as well as the internal relationships of the skull bones, are best seen in sagittal section. (b) The hard palate, the sphenoid bone, parts of the temporal bone, and the occipital bone with its foramen magnum may be seen in the inferior view.
depressions
Depression is the downward movement of structures of the body, e.g. depression of a shoulder joint lowers the corresponding arm vertically downwards. The movement of depression is the opposite of the movement of elevation.
description and boundaries of bone
Each forms anterior portion of face; upper jaw and parts of hard palate, inferior parts of orbits, and part of the walls of nasal cavity
description and boundaries of bone
Each forms posterior part of hard palate; also forms small part of nasal cavity and orbit wall
compare and contrast upper and lower limb bud development
Early limb buds are composed of lateral plate mesoderm and covered by a layer of ectoderm (see section 5.6a). The musculature of the limbs forms from somitic mesoderm that migrates to the developing limbs during the fifth week of development. At the apex of each limb bud, part of the ectoderm forms an elevated thickening called the apical ectodermal (ek-tō-der′măl) ridge. By mechanisms not completely understood, this ridge "signals" the underlying tissue to form the various components of the limb. Initially, the limb buds are cylindrical. The distal portion of the upper limb bud forms a rounded, paddle-shaped hand plate by the early fifth week. It later becomes both the palm and fingers. In the lower limb bud, a corresponding foot plateforms during the sixth week. These plates develop longitudinal thickenings called digital rays, which eventually form the digits. The digital rays in the hand plate appear in the late sixth week, and the foot digital rays appear during the early seventh week. The digital rays initially are connected by intermediately placed tissue, which later undergoes programmed cell death (apoptosis; see section 4.10). Thus, as this intermediate tissue dies, notching occurs between the digital rays, and separate digits are formed. This process occurs in the seventh week and is complete by the eighth week for both the fingers and the toes. As mentioned in section 7.4, bone forms by either intramembranous ossification or endochondral ossification. The flat bones of the skull; several facial bones, including the zygomatic, maxilla, and mandible; and the central part of the clavicle are formed from intramembranous ossification, whereas almost all of the remaining bones of the skeleton form through endochondral ossification.
selected features and their functions
External occipital crest:Attachment site for ligaments External occipital protuberance:Attachment site for neck ligaments and muscles Inferior and superior nuchal lines:Attachment sites for neck ligaments and muscles Occipital condyles:Articulate with first cervical vertebra
nuchal lines and external occipital protuberance
External surface of occipital bone is relatively smooth, with no major bony projections; external occipital protuberance is rounded Well-demarcated nuchal lines and a prominent bump or "hook" for external occipital protuberance
description and boundaries of bone
Forms inferior and posterior part of nasal septum
description and boundaries of bone
Forms part of anterior cranial fossa; part of nasal septum, roof and lateral walls of nasal cavity; part of medial wall of orbit
description and bounderies of bone
Forms part of the base of the skull; posterior part of orbit; part of anterior and middle cranial fossae
descriptions and bounderies
Forms posteroinferior part of the skull, including most of posterior cranial fossa; forms part of base of the skull
selected featured and their functions
Frontal process:Articulates with frontal bone Temporal process:Articulates with temporal bone to form zygomatic arch Maxillary process:Articulates with maxilla
Internal view of cranial base
Here we see the frontal bone surrounding the delicate cribriform (krib′ri-fōrm; cribrum = sieve, forma = form) plate of the ethmoid bone. The plate has numerous perforations called the cribriform foramina, which provide passageways for the olfactory nerves (CN I; see sections 13.9 and 16.3a) into the superior portion of the nasal cavity. The anteromedial part of the cribriform plate exhibits a midsagittal elevation called the crista galli (kris′tă = crest; gal′lē = of a rooster), to which the cranial dural septa of the brain attach
Identify the similarities and differences between male and female skulls.
Human female and male skulls display some obvious differences in general shape and size, a phenomenon known as sexual dimorphism. Typical "female" features tend to be gracile (delicate, small), whereas "male" features tend to be more robust (larger, sturdier, bulkier)
selected features and their functions
Hypophyseal fossa:Depression that houses pituitary gland Body: Houses sphenoidal sinuses Sella turcica:Bony enclosure around hypophyseal fossa Optic groove:Depression on body between the optic canals Medial and lateral pterygoid plates:Attachment sites for chewing muscles Lesser wings:Form part of anterior cranial fossa; contain optic canals Greater wings: Form part of middle cranial fossa, lateral surface of skull, and orbits Sphenoidal sinuses:Lighten bone, moisten inhaled air, and give resonance to voice2
differentiate between supination and pronation of the forearm
In anatomic position, the palm of the hand is facing anteriorly, and the bones of the forearm are said to be insupination (sū′pi-nā′shŭn) (figure 8.26c). Note that the radius and the ulna are parallel with one another. If you view your own supinated forearm, the radius is on the lateral (thumb) side of the forearm, and the ulna is on the medial (little finger) side. Pronation (prō-nā′shŭn) of the forearm requires that the radius cross over the ulna and that both bones pivot along the interosseous membrane (figure 8.26d). 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.
describe the articulations of the humerus
Its proximal end has a hemispherical head that Page 278articulates with the glenoid cavity of the scapula. The prominent greater tubercle is positioned lateral to the head and helps form the rounded contour of the shoulder. The lesser tubercle is smaller and located more medial to the head. Between the two tubercles is the intertubercular sulcus (also called bicipital sulcus or bicipital groove), a depression that contains the tendon of the long head of the biceps brachii muscle
Pterion
Junction of frontal, parietal, sphenoid, and temporal bones
lumbar vertebrae
Largest
female characteristics and male
Less massive; gracile processes, less prominent muscle markings More massive; more robust processes, more muscle markings General width Pelvis wider; ilia more flared Pelvis narrower; ilia more vertically oriented and less flared Pelvic inlet Spacious, wide and oval Heart-shaped Greater sciatic notch Wide and shallow Narrow and U-shaped, deep Obturator foramen Smaller and triangular Larger and oval Subpubic angle Broader, more convex; usually greater than 100 degrees Narrow, V-shaped; usually less than 90 degrees Body of pubis Longer; more rectangular Short; triangular Preauricular sulcus Usually present Usually absent Sacrum Shorter and wider; flatter sacral curvature Narrower and longer; more curved (greater sacral curvature) Ischial spine Rarely projects into pelvic outlet frequently roatetd inward projects into pelvic outlet
Anterior view of skull
Major structures are frontal bone (forehead), zygomatic bones (cheekbones), maxillae, and mandible. Maxilla and mandible bear teeth. Contain Orbits and Nasal cavities
describe the three arches of the foot and their functions
Normally, the sole of the foot is arched, which helps it support the weight of the body and ensures that the blood vessels and nerves on the sole of the foot are not pinched when we are Page 292 standing. The three arches of the foot are the medial longitudinal, lateral longitudinal, and transverse arches
inferior basal view of skull
On the posterior aspect of either side of the palate are the medial and lateral pterygoid (ter′i-goyd; pteryx = winglike) plates of the sphenoid bone. Together, both plates form a pterygoid process. Medially adjacent to these structures are the internal openings of the nasal cavity, called the choanae (kō′an-ē; sing., choana, kō′an-ă; funnel).
identify skeletal features common to the upper and lower limbs
Our upper and lower limb skeletons share some common features based on this evolutionary history, and they exhibit some differences based on the primary functions of each limb. Figure 8.22 summarizes the similarities. The proximal part of both upper and lower limbs are supported by a girdle of bones; the pectoral girdle (clavicles and scapulae) holds the upper limbs in place, whereasPage 276the pelvic 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 the 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 both contain either 5 metacarpals (palm of hand) or 5 metatarsals (arch of foot), and each contains a total of 14 phalanges (bones of the fingers and toes, respectively).
carotid canal
Petrous part of the temporal bone function is internal carotid artery.
Cervical vertebra
Small
locate and identify the auditory ossicles
The auditory ossicles and the hyoid bone are bones of the axial skeleton associated with the skull.are three tiny ear bones housed within the petrous part of each temporal bone. These bones—the malleus (mal′ē-us), the incus (ing′kŭs), and the stapes
describe the changes to the ossa coxae as a person age
The auricular surface of a young adult typically has some billowing texture to it (e.g., appears to have "hills" and "valleys"), and the surface is fine-grained. As the auricular surface ages, the billowing flattens out and the surface becomes more coarse and granular. In much older individuals, the surface may develop some bony lipping (evidence of osteoarthritic changes) and the surface becomes even more rough and irregular. Osteologists also have documented that the symphysial surface of the pubis undergoes uniform, age-related changes as well. In fact, the symphysial surface has become one of the most reliable indicators for estimating age at death. In a young adult (age range 15-24), the symphysial surface is billowed, and no well-formed rim is found around the surface. As the person ages, this billowing becomes more flattened, and a bony rim begins to form around the circumference of the symphysial surface. This rim is completed about ages 35-50 for most individuals. Once the rim is complete, the symphysial surface becomes depressed and concave and may become pitted in much older individuals. The rim or border may start to break down, and bony lipping (arthritis) develops along the edges of the symphysial surface. These last stages typically occur after age 50.
compare and contrast the anatomy of male and female pelves
The body of the pubis in females is much longer and almost rectangular in shape, compared to the shorter, triangular-shaped male pubic body. The subpubic angle (or pubic arch)is the angle formed when the left and right pubic bones are aligned at their symphysial surfaces. Because females have much longer pubic bones, the corresponding subpubic angle is much wider and more convex, usually much greater than 100 degrees. The male subpubic angle is much narrower and typically does not extend past 90 degrees.
verterbal foramen
The body together with the vertebral arch enclose an opening called the
describe the phalanges and their relative locations
The bones of the toes (like the bones of the fingers and pollex) are called phalanges. The toes contain a total of 14 phalanges. The great toe is the hallux (hal′ŭks; hallex = great toe), and it has only 2 phalanges (proximal and distal); each of the other four toes has 3 phalanges (proximal, middle, and distal).
list the bones that form the orbital and nasal complexes
The bony cavities called orbits enclose and protect the eyes and the muscles that move them. The orbital complexconsists of seven bones that form each orbit.
locate and identify the carpals and metacarpals
The carpals(kar′păl; karpus = wrist) are small, short bones that form the wrist. They are arranged in two rows (a proximal row and a distal row) of four bones each and allow for the multiple movements possible at the wrist.The proximal row of carpal bones, listed from lateral to medial, are the scaphoid (skaf′oyd; skaphe = boat), lunate(lū′nāt; luna = moon), triquetrum (trī-kwē′trŭm; triquetrus = three-cornered), and pisiform (pis′i-fōrm; pisum = pea, forma= appearance). The distal row of the carpal bones, listed from lateral to medial, are the trapezium (tra-pē′zē-ŭm; trapeza = table), trapezoid (trap′ĕ-zoyd), capitate (kap′i-tāt), and hamate(ha′māt; hamus = hook). Bones in the palm of the hand are called metacarpals (met′ă-kar′păl; meta = beyond). Five metacarpal bones articulate with the distal carpal bones and support the palm. Roman numerals I-V denote the metacarpal bones, with metacarpal I located at the base of the thumb, and metacarpal V at the base of the little finger.
cranial fossae
The contoured floor of the cranial cavity exhibits three curved depressions called the cranial fossae
fetal skull
The frontal bone, which forms the forehead. In the fetus, the frontal bone is in two halves, which fuse (join) into a single bone after the age of eight years. The two parietal bones, which lie on either side of the skull and occupy most of the skull.
identify key landmarks of the femur
The greater trochanter (trō-kan′ter; a runner) projects laterally from the junction of the neck and shaft. A lesser trochanter is located on the femur's posteromedial surface.These are rough processes that serve as attachment sites for powerful gluteal and thigh muscles (see section 11.9a).The greater and lesser trochanters are connected on the posterior surface of the femur by a thick oblique ridge of bone called the intertrochanteric (in′ter-trō-kan-tār′ik) crest. Anteriorly, a raised intertrochanteric line extends between the two trochanters and marks the distal edge of the hip joint capsule. Inferior to the intertrochanteric crest, the pectineal line marks the attachment of the pectineus muscle; the gluteal (glŭ′tē-ăl; gloutos = buttock) tuberosity marks the attachment of the gluteus maximus muscle (see section 11.9a). The gluteal tuberosity and pectineal line merge inferiorly into an elevated, midline ridge called the linea aspera (lin′ē-ă as′pĕr-ă), where many thigh muscles attach. Distally, the linea aspera branches into medial and lateral supracondylar lines. A flattened, triangular area, Page 288called the popliteal (pop-lit′ē-ăl; poples = ham of knee) surface, is bordered by these lines. The medial supracondylar ridge terminates in the adductor tubercle. This is a rough, raised projection that is the site of attachment for the adductor magnus muscle (see section 11.9). On the distal, inferior surface of the femur there are two smooth, oval articulating surfaces called the medial and lateral condyles. Superior to each condyle are projections called the medial epicondyle and lateral epicondyle, respectively. When you flex your knee, you can palpate these epicondyles in the thigh on the sides of your knee joint. The medial and lateral supracondylar lines terminate at these epicondyles. On the distal posterior surface of the femur, a deep intercondylar fossa separates the two condyles. A smooth medial depression on the anterior surface, called the patellar surface, is the place where the patella articulates with the femur. The patella (pa-tel′ă; patina = shallow disk), or kneecap, is a large, roughly triangular sesamoid bone housed within the tendon of the quadriceps femoris muscle (figure 8.32). The patella allows the tendon to glide more smoothly, and it protects the knee joint. The superior base of the patella is broad, whereas its inferior apex is pointed. The posterior aspect of the patella has an articular surface that articulates with the patellar surface of the femur.
neonatal ( infant) cranium
The infant's cranial bones are not yet large enough to surround the brain completely, so some cranial bones are interconnected by flexible areas of dense regular connective tissue in regions called fontanelles Fontanelles are sometimes referred to as the "soft spots" on a baby's head. The fontanelles enable some flexion in the bony plates within the skull during birth, thus allowing the child's head to pass through the birth canal to ease the baby's passage
list the fontanelles and the ages at which they close
The infant's cranial bones are not yet large enough to surround the brain completely, so some cranial bones are interconnected by flexible areas of dense regular connective tissue in regions called fontanelles (fon′tă-nel = little spring; sometimes spelled fontanels). Fontanelles are sometimes referred to as the "soft spots" on a baby's head. The fontanelles enable some flexion in the bony plates within the skull during birth, thus allowing the child's head to pass through the birth canal to ease the baby's passage
describe landmarks and features of an os coxae
The largest of the three coxal bones is the ilium (il′ē-ŭm; groin, flank), which forms the superior region of the os coxae and part of the acetabular surface. The wide, fan-shaped portion of the ilium is called the ala (ā′lă). The ala terminates inferiorly at a ridge called the arcuate (ar′kyū-āt; arcuatus = bowed) line on the medial surface of the ilium. On the medial side of the ala is a depression termed the iliac fossa. On the lateral surface of the ilium, the anterior, posterior, and inferior gluteal (glū′tē-ăl; gloutos = buttock) lines are attachment sites for the gluteal muscles of the buttock (see section 11.9a). The posteromedial side of the ilium exhibits a large, roughened area called the auricular(aw-rik′yū-lăr; auris = ear) surface, where the ilium articulates with the sacrum. The superiormost ridge of the ilium is the iliac crest. Palpate the posterosuperior edges of your hips; the ridge of bone you feel on each side is the iliac crest. The iliac crest arises anteriorly from a projection called the anterior superior iliac spine and extends posteriorly to the posterior superior iliac spine. Located inferiorly to the ala of the ilium are the anterior inferior iliac spine and the posterior inferior iliac spine. The posterior inferior iliac spine is adjacent to a prominent greater sciatic notch (sī-at′ik; sciaticus = hip joint), through which the sciatic nerve extends to the lower limb (see section 14.5g). The ilium fuses with the ischium (is′kē-ŭm; ischion = hip) near the superior and posterior margins of the acetabulum. Posterior to the acetabulum, the prominent triangular ischial(is′kē-ăl) spine projects medially. The bulky bone superior to the ischial spine is called the body of the ischium. The lesser sciatic notch is a semicircular depression inferior to the ischial spine. The posterolateral border of the ischium is a roughened projection called the ischial tuberosity. The ischial tuberosities also are called the sitz bones by some health professionals and fitness instructors because they support the weight of the body when seated. If you palpate your buttocks while in a sitting position, you can feel the large ischial tuberosities. An elongated ramus (rā′mŭs; pl., rami, rā′mē) of the ischium extends from the ischial tuberosity toward its anterior fusion with the pubis. The pubis (pyū′bis) fuses with the ilium and ischium at the acetabulum. The ramus of ischium fuses anteriorly with the inferior pubic ramus to form the ischiopubic ramus(figure 8.28). The superior pubic ramus originates at the anterior margin of the acetabulum. Between the superior and inferior pubic rami is an anteriorly placed mass of bone called the body of the pubis. The obturator (ob′tū-rā-tŏr; obturo = to occlude) foramen is a space in the os coxae that is encircled by both pubic and ischial rami. In a living individual, this foramen is covered with a connective tissue membrane. A roughened ridge, called the pubic crest, is located on the anterosuperior surface of the superior pubic ramus, and it ends at the pubic tubercle. A roughened area on the body of the pubis, called the symphysial (sim-fiz′ē-ăl; growing together) surface or pubic symphysis, denotes the site of articulation between the pubic bones. On the medial surface of the Page 283pubis, the pectineal (pek-tin′ē-ăl) lineoriginates and extends diagonally across the pubis to merge with the arcuate line.
three arches
The medial longitudinal arch is the highest of the three arches and extends from the heel to the great toe. It is formed from the calcaneus, talus, navicular, and cuneiform bones and metatarsals I-III. The medial longitudinal arch prevents the medial side of the foot from touching the ground and gives our footprint its characteristic shape (figure 8.35d). The lateral longitudinal arch is not as high as the medial arch, so the lateral part of the foot does contribute to a footprint. This arch extends between the little toe and the heel, and it is formed from the calcaneus and cuboid bones and metatarsals IV and V. The transverse arch runs perpendicular to the longitudinal arches. It is formed from the distal row of tarsals and the bases of all five metatarsals.
describe the location and function of the patella
The patella (pa-tel′ă; patina = shallow disk), or kneecap, is a large, roughly triangular sesamoid bone housed within the tendon of the quadriceps femoris muscle (figure 8.32). The patella allows the tendon to glide more smoothly, and it protects the knee joint. The superior base of the patella is broad, whereas its inferior apex is pointed. The posterior aspect of the patella has an articular surface that articulates with the patellar surface of the femur.
compare and contrast the pelvic inlet and pelvic outlet
The pelvic inlet, also known as the superior pelvic aperture, is the superiorly positioned space enclosed by the pelvic brim. In other words, the pelvic brim is the bony, oval ridge of bone, whereas the pelvic inlet is the space surrounded by the pelvic brim. The pelvic inlet is the opening at the boundary between the true pelvis and the false pelvis. The pelvic outlet, also known as the inferior pelvic aperture, is the inferiorly placed opening bounded by the coccyx, the ischial tuberosities, and the inferior border of the symphysial surface. In males, the ischial spines commonly project into the pelvic outlet, thereby narrowing the diameter of this outlet. In contrast, female ischial spines less frequently project into the pelvic outlet (so the birth canal will not be obstructed by these bony prominences). The pelvic outlet is covered with muscles and skin, and it forms the body region called the perineum (per′i-nē′ŭm) (see figure 11.17). The width and size of the pelvic outlet are especially important in females, because the opening must be wide enough to accommodate the fetal head during childbirth (see
Posterior View of Skull
The posterior view of the skull in figure 8.5b shows a portion of the occipital, parietal, and temporal bones, as well as the lambdoid suture between the occipital and parietal bones. Within the lambdoid suture, there may be one or more sutural bones.
name the four spinal curvatures of an adult vertebral column
The primary curvesare the thoracic and sacral curvatures, and they are present at birth. These curvatures arch posteriorly and result in the vertebral column being C-shaped. The secondary curves are called the cervical and lumbar curvatures, and they appear after birth. These curvatures arch anteriorly and are also known as compensation curvesbecause they help shift the trunk weight over the legs.
sella turcica
The relatively large sphenoid is located posterior to the frontal bone. It is often referred to as a "bridging bone" because it unites the cranial and facial bones. The lateral expansions of the sphenoid bone are called the greater wings and the lesser wings of the sphenoid.
describe the features found on all ribs
The ribs are elongated, curved, flattened bones that originate on or between the thoracic vertebrae and end in the anterior wall of the thorax
clavicle characteristics
The superior surface of the clavicle is relatively smooth and the inferior surface is roughened (figure 8.23). On the inferior surface, near the acromial end, is a rough tuberosity called the conoid (kō′noyd; konoeides = cone-shaped) tuberclefor the conoid ligament (part of the coracoclavicular ligament of the shoulder joint; see section 9.7b). The inferiorly located prominence at the sternal end of the clavicle is the costal tuberosity, for the attachment of the shoulder's costoclavicular ligament.
compare and contrast the features of the radius and the ulna
The shaft of the radius curves slightly and leads to a wider distal end, where there is a laterally placed styloid (stī′loyd) process. This bony projection can be palpated on the lateral side of the wrist, just proximal to the thumb. On the distal medial surface of the radius is an ulnar notch, which articulates with the medial surface of the distal end of the ulna at the distal radioulnar joint. The ulna (ŭl′nă) is the longer, medially placed bone of the forearm. At the proximal end of the ulna, a C-shaped trochlear notch interlocks with the trochlea of the humerus.The posterosuperior aspect of the trochlear notch has a prominent projection called the olecranon. The olecranon articulates with the olecranon fossa of the humerus and forms the posterior "bump" of the elbow. The inferior lip of the trochlear notch, called the coronoid process, articulates with the humerus at the coronoid fossa. Lateral to the coronoid process, a smooth, curved radial notchaccommodates the head of the radius and helps form the proximal radioulnar joint. Also at the proximal end of this bone is the tuberosity of ulna. At the distal end of the ulna, the shaft narrows and terminates in a knoblike head that has a posteromedial styloid process. The styloid process of the ulna may be palpated on the medial (little finger) side of the
compare the structures of fetal, child, and adult skulls
The shape and structure of cranial elements differ between infants and adults, causing variations in their proportions and size. The most significant growth in the skull occurs before age 5, when the brain is still growing and exerting pressure against the developing skull bones' internal surface.Brain growth is 90-95% complete by age 5, at which time cranial bone growth is close to completion, and the cranial sutures are almost fully developed.
gridles
The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of the clavicle, scapula, and coracoid.
Compare and contrast the composition and functions of the axial and appendicular skeletons?
The skeletal system is organized into two divisions: the axial skeleton and the appendicular skeleton
distinguish between the cranial and the facial bones
The skull is composed of both cranial and facial bones. Cranial bones form the rounded cranium (krā′nē-um; kranion = skull), which completely surrounds and encloses the brain.1 The cranium consists of eight bones that form a roof and a base. The roof of the cranium, called the calvaria (kal-vā′rē-ă), is composed of part of the frontal bone, the parietal bones, and part of the occipital bone.
adult skull
The skull undergoes many more changes as we age. The maxillary sinus becomes more prominent after age 5, and by age 10 the frontal sinus is becoming well formed. Later, the cranial sutures start to fuse and ossify. As a person ages, the teeth start to wear down from use, a process called dental attrition. Finally, if an individual loses some or all of his or her teeth, the alveolar processes of the maxillae and mandible regress and eventually disappear.
explain the sequence of curvature development
The spinal curvatures appear sequentially during fetal, newborn and child development stages which is the primary curves The cervical curvature appears when the child is first able to hold up its head without support( usually 3-4) months of age the lumbar curvature appears when the child is learning to stand and walk ( typically by 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
describe the functional reasons for differences between upper and lower limbs skeletons ?
The structural differences between the upper and lower limb skeletons arise from the functional differences. Understanding these general differences between upper and lower limbs will make the study of their individual bones easier. 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 the shoulder joints) are the most frequently injured.
superior view of skull
The superior view of the skull in figure 8.5a primarily shows four of the cranial bones: the frontal bone, both parietal (pă-rī′ĕ-tăl; paries = wall) bones, and the occipital (ok-sip′i-tăl; occiput = back of head) bone. The articulation between the frontal and parietal bones is the coronal suture, so named because it runs along a coronal plane. The sagittal suture connects the left and right parietal bones along the midline of the skull.
locate and identify the tarsals and metatarsals
The talus, calcaneus, and navicular bone are considered the proximal row of tarsal bones. The superiormost and second largest tarsal bone is the talus (tā′lŭs; ankle bone), which articulates with the tibia. The calcaneus (kal-kā′nē-ŭs) is the largest tarsal bone and forms the heel. Its posterior end is a rough, knob-shaped projection that is the point of attachment for the calcaneal (Achilles) tendon extending from the strong posterior leg muscles (see section 11.9c).The navicular (nă-vik′yū-lăr; navis = ship) bone is on the medial side of the ankle. Page 291 The distal row of four tarsal bones includes the cuneiforms and the cuboid bone. The medial cuneiform(kū′nē-i-fōrm; cuneus = wedge), intermediate cuneiform, and lateral cuneiform bones are wedge-shaped bones that articulate with and are positioned anterior to the navicular bone. The laterally placed cuboid (kyū′boyd; kybos = cube) bone articulates at its medial surface with the lateral cuneiform and at its posterior surface with the calcaneus. The metatarsals (met′ă-tar′săl) of the foot are five long bones similar in arrangement and name to the metacarpal bones of the hand. They form the arched sole of the foot and are identified with Roman numerals I-V, proceeding medially to laterally. The metatarsals articulate proximally with either the cuneiform bones or the cuboid bone. Distally, each metatarsal bone articulates with a proximal phalanx. At the head of the first metatarsal are two tiny sesamoid bones, which insert on the tendons of the flexor hallucis brevis muscle and help these tendons move more freely (see section 11.9d).
Lateral temporal bone
The temporal process of the zygomatic bone and the zygomatic process of the temporal bone fuse to form the zygomatic arch The zygomatic arch terminates superior to the point where the mandible articulates with the mandibular (man-dib′ū-lăr) fossa of the temporal bone. This articulation is called the temporomandibular joint (TMJ)
paranasal sinuses
The term paranasalrefers to their being located adjacent to the nasal cavity. The sinuses have a mucous membrane lining that helps to humidify and warm inhaled air. Additionally, the sinus spaces reduce the weight of the skull bones in which they are located, and they provide resonance to the voice. The paranasal sinuses are air-filled chambers within the frontal, ethmoid, and sphenoid bones and the maxillae. They are shown in (a) anterior and (b) lateral views. They are lined with a mucous membrane and are connected by ducts to the nasal cavity.
describe the features of the tibia and fibula
The tibia (tib′ē-ă; large shinbone) is the medially placed bone and the only weight-bearing bone of the leg (crural region). Its broad, superior head has two relatively flat surfaces, themedial and lateral condyles, which articulate with the medial and lateral condyles of the femur, respectively. Separating the condyles of the tibia is a prominent ridge called the intercondylar eminence (em′i-nens). On the proximal posterolateral side of the tibia is a fibular articular facet, where the head of the fibula articulates to form the superior(or proximal) tibiofibular joint. The rough anterior surface of the tibia near the proximal condyles is the tibial tuberosity, which can be palpated just inferior to the patella and marks the attachment site for the patellar ligament. The anterior border (or margin), often referred to as the shin, is a prominent ridge that extends distally along the anterior tibial surface from the tibial tuberosity. The tibia narrows distally, but at its medial border it forms a large, prominent process called the medial malleolus (ma-lē′ō-lŭs; malleus = hammer). Palpate the medial side of your ankle; the bump you feel is your medial malleolus. There is a fibular notch on the distal posterolateral side of the tibia where the fibula articulates and forms the inferior (or distal) tibiofibular joint. On the inferior distal surface of the tibia is the smooth inferior articular surface for the talus, one of the tarsal bones. The fibula (fib′yū-lă; buckle, clasp) is the long, thin, lateral bone of the leg. The fibula does not bear any weight, but several muscles attach to it. The rounded, knoblike head of the fibula is slightly inferior and posterior to the lateral condyle of the tibia. Distal to the fibular head is the neck of the fibula, followed by its shaft. The fibula's distal tip, called the lateral malleolus, extends laterally to the ankle joint, where it provides lateral stability. Palpate the lateral side of your ankle; the bump you feel is your lateral malleolus.
spine of scapula
The triangular shape of the scapula forms three sides, or borders. The superior border is the horizontal edge of the scapula superior to the spine of the scapula; the medial border (also called the vertebral border) is the edge of the scapula closest to the vertebrae; and the lateral border (also called the axillary border) is closest to the axilla. A suprascapular notch (which in some individuals is a suprascapular foramen) in the superior border provides passage for the suprascapular nerve and blood vessels. Between these borders are the superior, inferior, and lateral angles. The superior angle is located between the superior and medial, while the inferior angle is positioned between the medial and lateral borders. The lateral angle is primarily made up of the cup-shaped, shallow glenoid (glē′noyd; glen′oyd; resembling a socket) cavity, or glenoid fossa, which articulates with the humerus, the bone of the arm. The broad, relatively smooth anterior surface of the scapula is called the subscapular (sŭb-skap′yū-lă r; sub = under) fossa. A large muscle called the subscapularis overlies this fossa. The spine subdivides the posterior surface of the scapula into two shallow fossae. The depression superior to the spine is the supraspinous (sū-pră-spī′nŭs; supra = above) fossa;inferior to the spine is a broad, extensive surface called the infraspinous fossa. The supraspinatus and infraspinatus muscles, respectively, occupy these fossae (see section 11.8b).
differentiate between the true and false pelves
The true pelvis, also known as the lesser pelvis, lies inferior to the pelvic brim. It encloses the pelvic cavity and forms a deep bowl that contains the pelvic organs. The false pelvis, also known as the greater pelvis, lies superior to the pelvic brim. It is enclosed by the alae of the ilia. It forms the inferior region of the abdominal cavity and houses the inferior abdominal organs.
describe how the limb buds form
The upper limb buds appear early in the fourth week (approximately day 26), and the lower limb buds appear a few days later (day 28) (figure 8.36). Lower limb development lags behind upper limb development by about 2 to 4 days. The upper and lower limbs form proximodistally, meaning that the more proximal parts of the limbs form first (in weeks 4-5), whereas the more distal parts differentiate later.
list the five types of verbrae
The vertebral column is partitioned into five divisions, or regions (figure 8.16). Vertebrae are identified by using a capital letter to denote their region, followed by a numerical subscript that indicates their sequence, going from a superior to an inferior location:
inferior nasal conchae
along the inferolateral walls of the nasal cavity are two scroll-shaped bones .
identify the three main components of the sternum and their features
also referred to as the breastbone, is a flat bone that forms in the anterior midline of the thoracic wall. Its shape has been likened to that of a sword. The sternum is composed of three parts: the manubrium, the body, and the xiphoid process.
Ramus
angular extension of bone relative to the rest of the structures
hypoglossal canal
antero-medial to occipital condyle of occipital bone ; hypoglossal nerve( CN . XII)
process
any marked bony prominence
describe the locations of the sutures between the cranial bones
are immovable fibrous joints (see section 9.2b) that form the boundaries between the cranial bones (see figures 8.5-8.7). Dense regular connective tissue connects cranial bones firmly together at a suture. The sutures often have intricate, interlocking forms resembling puzzle pieces. Numerous sutures are present in the skull, each with a specific name. Many of the smaller sutures are named for the bones or features they interconnect.
thoracic and sacral curvatures
are primary curves and they are present at birth, these curvatures arch posteriorly and result in the vertebral column being c-shaped.
cervical and lumbar curvatures
are the secondary curves they appear after birth. These curvatures arch anteriorly and are also known as compensation curvesbecause they help shift the trunk weight over the legs.
bone markings
are the surface features that are characterize each bone in the body. projections from the bone surface mark the points where muscles, tendons and ligaments attach.
Sphenoid bone
articulates with the frontal, parietal and temporal bone.
palatine bone
associated passageways greater and lesser palatine foramina
maxilla
associated passageways incisive foramen infraorbital foramen
sphenoid bone
associated passageways ; Foramen lacerum (with temporal and occipital bones) Foramen ovale Foramen rotundum Foramen spinosum Optic canal Pterygoid canal Superior orbital fissure
ethmoid bone
associated passagways cribriform foramina
sinus
cavity or hollow space in a bone
zygomatic bone
cheek bone associated passageways are none
mastoid and sphenoidal fontanelles
close relatively quickly after birth. However others are present until many months after birth, when skull bone growth finally starts to keep pace with brain growth.
identify and locate the clavicle and its landmarks
commonly known as the collarbone, is an elongated, S-shaped bone that extends between the manubrium of the sternum and the acromion of the scapula Its sternal end (medial end) is roughly pyramidal in shape and articulates with the manubrium of the sternum, forming the sternoclavicular joint (see section 9.7b). The acromial end (lateral end) of the clavicle is broad and flattened. The acromial end articulates with the acromion of the scapula, forming the acromioclavicular joint. You can palpate your own clavicle by first locating the superior aspect of your sternum and then moving your hand laterally. The curved bone you feel under your skin, and close to the neck opening of your shirt, is your clavicle.
orbital complex
consits of seven bones that form each orbit.
skull
cranium is made up of 22 bones and it is the most complex structure
Cribriform foramina
cribriform plate of the ethmoid bone ; olfactory nerves
Alveolus
deep pit or socket in the maxillae or mandible
anterior fontanel
doesn't close until about 15 months of age
description and bounderies of the bone
each forms a cheek and lateral part of the orbit
description and boundries of bone
each forms part of the medial wall of the orbit
internal occipital protuberance
extends from the protuberance to the posterior border of the foramen magnum. Large grooves along the internal aspect of the cranium are formed from impressions from the dural venous sinuses of the brain that lie within them
coronal suture
extends laterally across the superior surface of the skull along a coronal plane. It represents the articulation between the anterior frontal bone and the more posterior parietal bones.
lambdoid suture
extends like an arc across the posterior surface of the skull. This suture is the site where the parietal bones and the occipital bone articulate. It is named for the Greek letter lambda, which its shape resembles.
mental protuberance
female; more pointed and triangular-shaped less forward projection male; squarish, more forward projection
supraorbital margin
female; thin sharp border male; thick rounded blunt border
general size and appearance
females; more gracile (delicate and small) less prominet muscle markings males: more robust (big and bulky) more prominent muscle markings
mastoid process
females; relatively small males: large may project inferior to external acoustic meatus
mandible (general features)
females; smaller and ligher males: larger, heavier, more robust
mandibular angle
females; typically greater than 125 degrees males: typically less obtuse and less than 125 degrees ( closer to 90 degrees) angle edges may flare outward
squamous part of frontal bone
females; usually more vertically orientated and rounded than males males exhibits a sloping angle
Fossa
flattened or shallow depression
Cranial
form the rounded cranium which complelty surrounds and encloses the brain. The cranium consist of eight bones that form a roof and . a base. The roof of the cranium called the calvaria is composed of part of the frontal bones, the parietal bones, and the part of the occipital bone. The base of the cranium is composed of portions of the ethmoid, sphenoid, occipital and temporal bones.
twelve thoracic vertebrae
form 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.
description and bodaries of bone
forms the lower jaw
Maxillae
fuse in the midline to form most of the upper jaw and the lateral boundaries of the nasal cavity. The maxillae also help form a portion of both the floor of each orbit and the roof of the oral cavity.
foramen ovale
greater wing of of sphenoid bone; mandibular branch of trigeminal nerve (CN V2)
foramen spinosum
greater wing of sphenoid bone ; middle meaningless vessels.
foramen rotundum
greater wing of sphenoid bone; maxillary branch of trigeminal nerve (CNA v2)
each vertebra
has a superior and inferior articular processes that originate at the junction between the pedicles and laminae. each articular process has a smooth surface called articular facet.
describe how the ossa coxae articulate with each femur and scarum
he femur articulates with a deep, curved depression on the lateral surface of the os coxae called the acetabulum (as-ĕ-tab′yū-lŭm; shallow cup). The acetabulum contains a smooth, curved surface, called the lunate surface, which is C-shaped and articulates with the femoral head. The ilium, ischium, and pubis all contribute a portion to the acetabulum—thus, it represents a region where these bones have fused.
posterior fontanel
he posterior fontanelle normally closes around 9 months of age;
describe the functions of the vertebral column
he vertebral column provides vertical support for the body and supports the weight of the head. It helps maintain an upright body position. Most important, it houses and protects the delicate spinal cord.
body shape
heart shaped
Appendicular skeleton
included the bones of the upper and lower limbs and the girdles of the bones that attach the lower and upper limbs to the axial skeleton. The pectoral girdles consist of bones that hold the upper limbs in place whereas the pelvic girdle consist of bones that hold the lower limbs in place.
selected features and their functions
increase airflow turbulence in the nasal cavity
infraorbital foramen
inferior to each orbit int he maxilla, which is the passageway for blood vessels and nerves to the face.
infraorbital foramen
inferior to orbit in the maxilla ; infraorbital artery, infraorbital nerve
mental foramen
inferior to second premolar on anterolateral surface of mandible; mental blood vessels, mental nerve
describe the landmarks and features of the scapula
is a broad, flat, triangular bone that forms the shoulder blade (figure 8.24). You can palpate your scapula by putting your hand on your superolateral back region and moving Page 277your upper limb; the bone you feel moving is the scapula. The spine of the scapula is a ridge of bone on the posterior aspect of the scapula. It is easily palpated under the skin. The spine is continuous with a larger, posterior process called the acromion (a-krō′mē-on; akron = tip, omos = shoulder), which forms the bony tip of the shoulder. Palpate your upper shoulder; the prominent bump you feel is the acromion. The coracoid (kōr′ă-koyd) process is the smaller, more anterior, hook-shaped projection that is a site for muscle attachment.
hyoid bone
is a slender, curved bone located inferior to the skull between the mandible and the larynx (voice box) It does not articulate with any other bone in the skeleton. The hyoid has a medial body and two paired, hornlike processes, the greater cornua (kor′nū-ă = horn; sing. cornu, kōr′nū) and the lesser cornua. The cornua and body serve as attachment sites for tongue and anterior neck muscles and ligaments
the styloid process
is a thin pointed projection of bone located anteromedial to the mastoid process. it serves as an attachment site for several hyoid and tongue muscles.
Nasal cavity
is also seen in the anterior view. Anterior nasal spine; its inferior border is marked by anterior nasal spine.
jugular foramen
is an opening between the temporal and occipital bones that provide a passageway for the internal jugular vein and several nerves.
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.
Nasal complex
is composed of bones and cartilage that enclose the nasal cavity and the paranasal sinuses
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 L5superiorly, the first coccygeal vertebra inferiorly, and laterally with the two ossa coxae (hip bones).
mastoid process
is inferior and posterior from the extreranl acoustic meatus and its the bumbp you feel behind your exteranl ear openeing.
middle cranial fossa
is inferior and posterior to the anterior cranial fossa. it ranges from the posterior edge of the lesser wings of the sphenoid bone (anteriorly) to the anterior region of the petrous part of the temporal bone. it houses the temporal lobes of the brain and the pituitary gland
posterior cranial fossa
is is the most inferior an dposterior cranial fossa and extends fromt he posterior region of the petrous part of the temporal bones tot he occipital bone. this fossa supports part of the brainstem and the cerebullum.
Axial skeleton
is so names because it is composed of the bones along the central axis of the body which include the bones of the skull, vertebral column, sternum and the ribs. The main function of the axial skeleton is to form a framework that supports and protects the organ. The spongy bone of most axial Skelton contains hemopoietic tissue that is responsible for the blood cells formation.
the pituitary gland
is suspended inferiorly from the brain into the prominent midline depression between the greater and lesser wings.This depression is termed the hypophyseal fossa, and the bony enclosure around the hypophyseal fossa is called the sella turcica Anterior to the sella turcica are the optic canals through which the optic nerves (CN II) extend from the eyes in the orbits to the brain
carotid canal
is the anteromedial to the jugular foramen, the internal cartoid artery passes trhough this canal.
pariteal eminence
is the lateral surface of each parietal bone exhibits a rounded, smooth area.
describe the articulations of the femur
is the longest bone in the body as well as the strongest and heaviest (figure 8.31). The nearly spherical head of the femur articulates with the os coxae at the Page 287acetabulum. There is a small depression within the head of the femur, called the fovea (fō′vē-ă; a pit), or fovea capitis. Here a small ligament connects the head of the femur to the acetabulum. Distal to the head, an elongated, constricted neck joins the shaft of the femur at an angle. This results in a medial angling of the femur, which brings the knees closer to the midline.
body of sternum
is the longest part of the sternum and forms its bulk (the blade of the bony sword). Individual costal cartilages from ribs 2-7 are attached to the body at indented articular costal notches. The body and the manubrium articulate at the sternal angle, a horizontal ridge that may be palpated under the skin. The sternal angle is an important landmark in that the costal cartilages of the second ribs attach there; thus, it may be used to count the ribs.
external occipital protuberance
is the prominence on the posterior aspect of the skull.Palpate the back of your head; males tend to have a prominent, pointed external occipital protuberance, whereas females have a more subtle, rounded protuberance. Intersecting the external occipital protuberance are two horizontal ridges, the superior and inferior nuchal (nū′kăl) lines
anterior cranial fossa
is the shallowest of the three depressions. it is formed by the frontal bone , the ethmoid bone, and the lesser wings of the sphenoid bone. the anterior cranial fossa houses the frontal lobes of the brain.
Manubrium of sternum
is the widest and most superior portion of the sternum (the handle of the bony sword). The two clavicular notches of the sternum articulate with the left and right clavicles. The shallow superior indentation between the clavicular notches is called the suprasternal (or jugular) notch. A single pair of costal notchesrepresent articulations for the first ribs' costal cartilages.
cylindrical body
its the anterior region of each vertebra which is the weight bearing structure
Inferior orbital fissure
junctions maxilla, sphenoid and zygomatic bones; infraorbital nerve ( Branch of CN . V2)
lacrimal groove
lacrimal bone; nasolacrimal duct
lacrimal bone
lacrimal groove
selected featured and their functions
lacrimal groove; contains nasolacrimal duct
transeverse processes
large , thick and blunt
body shape
large oval or round
Tuberosity
large, rough projection
condyle
large, smooth, rounded oval structure
intervertebral foramina
lateral openings between adjacent vertebrae for spinal nerves it provides horizontally directed passageways through which spinal nerves extend to various parts of the body
sylomastoid foramen
lies between the mastoid process and the styloid process. the facial nerve extends through the stylomastoid foramen to inervate the facial muscles.
squamous part of the temporal bone
lies directly inferior to the squamous suture immediately posterolateral to the mandibular fossa is the tympanic part of the temporal bone which is called the external acoustic meatus.
spinous processes
long most project inferiorly
line (anatomy )
low ridge
Mandible
lower jaw passagways; mandibular foramen and mental foramen
petrous
makes the lateral regions of the cranial base of each temporal bone.
mandibular foramen
medial surface of ramus of mandible; inferior alveolar blood vessels, inferior alveolar nerve
thoracic vertebrae
medium size ( larger than cervical)
transverse processes
medium sized
fissure
narrow, stillike opeing trhough a bone
vomer
nasal septum no associated passageways
inferior nasal concha
no associated passageways
transverse foramina
none
transverse foramina
none( l)
costal facets for ribs
not present
costal facets for ribs
not present (c)
perpendicular plate
of the ethmoid forms the posterosperior portions the nasal septum, whereas the vomer forms the posterferior portions
parietal foramen
parietal bone near saggital suture.; parietal emissary vein
nasal septum
partition separating the right and left nasal cavities
parietal bone
passageway is parietal foramen ; description and boundaries of the bone are that each forms most of lateral and superior walls of the skull; Superior and inferior temporal lines:Attachment sites for temporalis muscle Parietal eminence:Forms rounded prominence on each side of the skull
Canal
passageway through a bone
occpital bone
passagways ;Foramen magnum Hypoglossal canal Jugular foramen (with temporal bone) Condylar canal
temporal bone
passagways; sylomastoid foramen, cartoid canal, external acoustic meatus and internal acoustic meatus , mastoid foramen, jugular foramen with occpital bone Each forms inferolateral wall of the skull; forms part of middle cranial fossa. Three parts are included below. Petrous part:Protectssensory structures in inner ear Squamous part:Attachment site of some jaw muscles Tympanic part: Houses external acoustic meatus Mastoid process:Attachment site of some neck muscles to extend or rotate head Styloid process:Attachment site for hyoid bone ligaments and muscles Zygomatic process:Articulates with zygomatic bone to form zygomatic arch Mandibular fossa:Articulates with mandible Articular tubercle:Limits displacement of head of mandible within mandibular fossa
spinous process
short (thick and blunt) project posteriorly.
transverse processes
small ( contain transverse foramina)
tubercle
small rounded projection
facet
small, flat, shallow surface
trochlea
smooth, grooved, pulley-like process
vertebral arch
structure that encloses the nerve cord and its posterior to the vertebral body
Cranial passageways
such as canals, fissures, and foramina that serve as passageways for blood vessels and nerves. The major foramina of the cranial and facial bones are summarized in
Frontal bone
supra orbital foramen or notch; forms the superior and anterior parts of the skull part of anterior cranial fossa and orbit. selected features and their functions Frontal crest:Attachment site for meninges to help stabilize brain within the skull Frontal sinuses:Lighten bone, moisten inhaled air, and give resonance to voice Orbital part:Forms roof of orbit Squamous part:Attachment of scalp muscles Supraorbital margin:Forms protective superior border of orbit Zygomatic process:Articulates with zygomatic bone
foramen magnum
the largest foramen and which is meaning is big hole. through this opening the spinal cord enters the cranial cavity and is continuous superiorly with the bran stem. on the either side of the foramne magnum are the occipital condyles which articulate with the first cervical vertebra of the vertebral column At the anteromedial edge of each condyle is a hypoglossal canal through which the hypoglossal nerve (CN XII) extends to innervate tongue muscles
mandible
the lower jaw is formed by the mandible. the prominent chin of the mandible is called the mental protuberance. The oral margins of the maxillae and mandible each have alveolar processes that contain the teeth.
