Axial Skeleton - Human Anatomy & Physiology - Chapter 7 Tortora

Which processes serve as an attachment for muscles?

2 transverse processes and 1 spinous process

How many bones are in the vertebral column?

26

How many bones are in the lumbar vertebrae?

5

How many bones in the sacrum vertebrae?

5 fused together

Sacrum

5 fused vertebrae, triangular shaped Strong foundation of pelvic girdle

Sesamoid Bones

-Develop in certain tendons where there is considerable friction, tension, and physical stress. -Functionally they protect tendons from excessive wear and tear -Ex: Palms, Soles, Kneecaps

Vertebrochondral Ribs

"False Ribs" Ribs 8-12 (5 pairs) Costal cartilage attaches either *indirectly does not attach* to the Sternum at all.

Vertebral Ribs

"Floating Ribs" Ribs 11 and 12 No costal cartilage Doesn't connect to the sternum at all

Flat Bones

-Generally thin -2 thin layers of compact bone tissue, enclosing a layer of spongy bone tissue. -Considerable protection and extensive muscle attachment -Red bone marrow is here -Ex: cranial bones, sternum, ribs

Vertebrosternal Ribs

"True Ribs" Ribs 1-7 Each have their own costal cartilage that connect to Body of sternum

Calvarian

aka skullcap Vault that houses the brain

Long bones

-Greater in length than width -Consist of a shaft and a variable number of extremities or epiphyses, and are slightly curved for strength. -Ex: femur, tibia, fibula, humerus, etc.

Kyphosis

"Hunchback" look increase in curvature, thoracic region Ex: Common in women w/ advanced osteoporosis (old people)

Nasal Septum

*Composed of bone & cartilage* 3 Components: Vomer, Septal cartilage, and perpendicular plate of the ethmoid bone.

Spina Bifida

*Congenital defect of the vertebral column, in which the laminae of L5 and/or S1 fail to develop normally and unite at the midline. -Protrusion of meninges and/or spinal cord through the defect in the laminae. -Presence of cystlike sac protruding from the backbone.

What is the function of Intervertebral Discs?

*Shock absorbers, constantly compressed -Protects nerves down the spine. -Form strong joints, permit various movements. -Account for 25% of the height of the vertebral column.

Where are Intervertebral Discs found?

-Are found between the bodies of adjacent vertebrae from the 2nd cervical vertebra to the sacrum

*Features of vertebrae*

-Body -Vertebral Arch -Several Processes (transverse, spinous, superior articular, inferior articular) -Vertebral Foramen

What are the functions of the vertebral column?

-Encloses and protects the spinal cord -Supports the head -Serves as a point of attachment for the ribs, pelvic girdle, and muscles of the back and upper limbs

How many bones are in the thoracic vertebrae?

12

How many bones are in the cervical vertebrae?

7

How many processes arise from the vertebral arch?

7

How many bones form the orbits (eye sockets)?

7 skull bones

What are the parts of intervertebral discs?

Annulus Fibrous & Nucleus Pulposus

Name the fontanels

Anterior (future Coronal Suture) Posterior (future Lambdoid Suture) Anterolaterals 2 (Future Squamous Suture) Posterolaters 2

Coronoid process

Anterior projection of the ramus of the mandible, insertion point for the temporalis muscle

What forms a transverse process?

At the point where a pedicle and lamninae join, a transverse process extends laterally

Lordosis

Bent backward, or "Hollow back" increase in curvature, lumbar region Ex: Pregnant women, fat people

Odontoid process

Bump on 2nd vertebrae (axis)

What are the normal curves of the vertebral column?

Cervical, Thoracic, Lumbar, Sacrum

What are the regions of the vertebral column?

Cervical, Thoracic, Lumbar, Sacrum, and Coccyx

Temporomandibular joint

Each articulation of the head of the mandible with the mandibular fossa of the temporal bone, mobile joint that allows us to move the lower jaw when we talk or chew

Internal Acoustic Meatus

Hearing apparatus with 3 little bones inside it.

What separations exist between vertebrae?

Intervertebral foramina & Intervertebral Discs

Mandible

Lower jaw Largest strongest facial bone Only movable skull bone

Superior/inferior orbital fissure

Jagged openings (on top or bottom) behind orbitals where the optic nerve enters

Inferior nasal conchae

Located in the inferolateral wall of the nasal cavity, help create turbulence in inhaled air

Scoliosis

Most common lateral bending of the vertebral column, usually in the thoracic region varying degrees

What makes up the Nasal Cavity?

Nasal Septum 3 Turbinates/Conchae (Superior, Middle, and Inferior) Nasal Bone

Annulus Fibrous

Outer fibrous ring of fibrocartilage around each disc.

Mental foramen

Penetrate body of mandible on each side to provide a passageway for nerves and blood vessels

Mental protuberance

Point of the chin

Condylar process

Posterior projection of each mandibular ramus

Craniosynostosis

Premature complete ossification of the sutures/fontanels

What do the foramina of the skull bones do?

Provide passages for nerves and blood vessels

What are some abnormalities with the curves of the vertebral column?

Scoliosis, Lordosis, Kyphosis, Spina Bifida

What are the functions of fontanels?

Serve as spacers for the growth of neighboring skull bones and provide some flexibility to the fetal skull, allowing the skull to change shape as it passes through the birth canal and later permitting rapid growth of the brain during infancy.

Palatine

Small, L-shaped bones; form part of the hard palate, nasal cavity, and eye orbit

Where can you find the paranasal sinuses?

The frontal, sphenoid, ethmoid, and macillae bones

*What are the different kinds of processes?*

Transverse (2) Spinous (1) Superior Articular Processes (2) Inferior Articular Processes (2) Facets

Auditory ossicles

Three tiny ear bones (malleus, incus, stapes) housed within petrous part of each temporal bone

Parietal Bone

Two separate bones on top of head. Forms the skullcap Bones are thin and curved and very strong

Mandibular notch

U-shaped depression between the condylar and coronoid processes of the mandible

Herniated Disc

aka Slipped Disc Is a condition in which the annulus fibrosus (outer portion) of the vertebral disc is torn, enabling the nucleus (inner portion) to herniate or extrude through the fibers.

Paranasal sinuses

are cavities in bones of the skull that are connected to the nasal cavity.

Fontanels

called "soft spots" are mesenchyme-filled spaces between the cranial bones of fetuses and infants. After birth, the fontanels fill in with bone and become sutures.

Vertebral Foramen

contains the spinal cord, adipose tissue, areolar CT, and blood vessels

Intervertebral Foramina

holes/spaces between the vertebrae

Nucleus Pulposus

inner soft, pulpy, highly elastic substance inside the Annulus Fibrous, inside an intervertebral disc.

Sternal Puncture

removal of bone marrow from the Manubrium by needle.

Alveolar Process

sockets for upper teeth

Broken nose usually refers to damage of...?

the septal cartilage rather than the nasal bones themselves.

Vertebral Body

thick, disc shaped anterior portion Weight bearing part of the vertebrae

What bones make up the body's trunk?

vertebral column, sternum, and ribs

Foramen magnum

Hole where the spinal cord enters the brain

How many facial bones are there?

14

Parts of the Appendicular Skeleton

Bones of the girdles Upper & Lower limbs

Inferior demifacet

Flat part on back of transverse processes

The mandible articulates with what?

the mandibular fossa and articular tubercle of the temporal bone to form the Temporomandibular Joint (TMJ)

Zygomatic Arch. Function Composed of...?

-Has lots of important muscles; like for chewing and facial expressions -Protects the face against blows. -Composed of zygomatic process and temporal bone.

*Thoracic Vertebrae*

-Middle 12 vertebra; curve of spine; -Articulates laterally with ribs w/ Costal facets. -Facets face posterolateral & anteromedial -Long spinous process

Sphenoid Bone features

-Optic Chiasma - Eyeballs go here -Sphenoid Sinus - open cavity to lighten the skull -3 Important foramen (Lacerum, Ovale, Spinosum)

Regions of the sphenoid bone

-Sella Turcica - pituitary gland sits here -Wings of optic foramen - optic nerves go through here

Short Bones

-somewhat cube-shaped -Nearly = in length and width -Consist of spongy bone tissue, except at surface, which has a thin layer of compact bone. -Ex: Wrist, most tarsal (ankle) bones

The Ethmoid bone forms...

1. Part of the anterior portion of the cranial floor 2. Medial wall of the orbits 3. Superior portion of the nasal septum 4. Most of the superior sidewalls of the nasal cavity

Temporal Bone Regions

1. Temporal Squama - flat region 2. Zygomatic Process - contributes to the zygomatic arch 3. Petrous Portion - auditory canals inside it

When does the sacral vertebrae begin to fuse?

16-18 years old

Embryotic form & Occipital form

2 occipital condyles rock on atlas/head

How many bones are in the skull?

22

Sternum

3 Parts: Manubrium, Body, and Xiphoid Process. Usually uses fuse by age 25

Lumbar

5 vertebrae, lower back. Largest & Strongest of vertebrae. Thickest vertebral discs Facets face medially & lateral

How many cranial bones are there?

8

Styloid process

A thin, pointed projection of bone Serves as an attachment site for several HYOID and tongue muscles

Regions of the Maxilla

Alveolar Process Orbital Process Palatine Process Maxillary Sinus

Body of vertebrae

Anterior region of each vertebra; rounded or cylindrical

Coronal suture

Between Frontal and Parietal bones.

Metopic Suture

Between the 2 frontal bones before the fuse together. Usually disappears between the ages of 6 and 8 years old.

Lambdoidal suture

Between the Parietal and Occipital bones.

Squamosal suture

Between the Temporal and Parietal bone of that side

Ethmoid

Between the eyes and behind the nose (but in front of the Sphenoid Bone)

Shaft

Big long bone of rib, connects to costal cartilage

Sternal angle

Body and manubrium of sternum articulate at this point

Hard Palate

Bony roof of the mouth. Formed by the palatine processes of the maxilla and horizontal palatine bones. Separates nasal and oral cavity

Xiphoid process

Bottom bone of sternum, "tailbone" of sternum. Is hyaline cartilage until your 40's. No ribs attached here, but some ab muscles attach here.

Inferior articular process

Bumps on bottom on vertebrae that connect them to other vertebrae

Superior articular process

Bumps on tops on vertebrae that connect them to other vertebrae

*Vertebral Prominens*

C7 "bump on the back of your neck" Has a large nonbifid spinous process

TMJ Syndrome

Characterized by dull pain around the ear, tenderness of the jaw muscles, a clicking/popping noise when opening or closing the mouth headache, tooth sensitivity, and abnormal wearing of teeth.

Pedicle

Connects body of vertebrae to transverse processes

Lamina

Connects spinous and transverse processes in the vertebrae

Why is costal cartilage important?

Contributes to the elasticity of the thoracic cage and prevent varying blows to the chest from fracturing the sternum and/or ribs.

Name the skull sutures

Coronal (Frontal) Sagittal Lamboid Squamous

Occipital condyle

Dents on either side of foramen magnum where the first cervical vertebra (atlas) articulates

Embryonic form of the Frontal bone

Originally 2 bones that are united soon after birth.

Cleft Palate

Failure to fuse the palatine processes of the maxillary bones

*Atlas*

First vertebrae [C1], holds head on neck Missing a body & spinous process

Occipital Bone features

Foramen magnum Occipital condyles Nuchal lines

Lacrimal

Form part of the medial wall of each orbit; articulate with nasal bone anteriorly and Ethmoid bone posteriorly. Lacrimal Sac - passes tears into the nasal cavity

Nasal

Form the bridge of the nose; medial edge of maxilla articulate with it's lateral edge

Occipital

Forms most the posterior and inferior portions of the cranium.

Frontal Bone

Forms part of the skullcap, the forehead, and the roof of the orbits.

Temporal Bone

Forms the inferior lateral aspects of the cranium and part of the cranial floor.

Name the cranial bones.

Frontal Parietal 2 Temporal 2 Occipital Sphenoid Ethmoid

Features of the frontal bone

Frontal squama Supraorbital margin Supraorbital foramen Supraorbital notch Frontal Sinuses

Maxillary Sinus

Largest of the paranasal sinuses Drains into the middle meatus of the nose.

Transverse process

Lateral projections on both sides of the vertebral arch

Cribiform Plate

Lies in the anterior floor of the cranium and forms the roof of the nasal cavity. Contains olfactory foramina (sense of smell)

Types of Bone

Long Short Flat Irregular Sesamoid

Temporal Bone Features

Mandibular Fossa External Auditory Meatus Mastoid Process Styloid Process

Gladiolus or Body

Middle bone of sternum. 2nd-10th ribs

Sagittal suture

Midline of the cranium and articulation between right and left parietal bones

Name the facial bones.

Nasal 2 Maxillae 2 Zygomatic 2 Lacrimal 2 Palatine 2 Inferior nasal conchae 2 vomer mandible

Tubercle

Part of individual rib that bumps out on the bottom of a rib

Neck

Part of individual rib that is between head and tubercle

Head

Part of individual rib that is closest to vertebrae

Features of Ethmoid Bone

Perpendicular Plate Cribiform Plate Crista Galli Superior & Middle Nasal Concha

Spinous process

Project posteriorly from left and right lamina

Mastoid process

Prominent bulge on the inferior surface of the temporal bone; an anchoring site for muscles that move the neck

Bone Functions

Protect the soft body parts and make movement possible. They also serve as landmarks for locating parts of other body systems.

Superior/inferior nuchal lines

Raised ridges on occipital bones in skull, points where neck and spine muscles attach

Features of the Mandible

Ramus Body Temporomandibular Joint

*Axis*

Second vertebrae [C2] Dens - peglike projection, goes through C1, allows side-to-side movement of the head (shake head to signify "no")

Hyoid

Slender, curved bone located inferior to the skull between the mandible and larynx u-shaped bone Does not articulate with any other bone. Supports the tongue and provides attachment for some tongue muscles and for some muscles of the pharynx and neck,

*Cervical Vertebrae*

Top 7 vertebrae (in the neck) 2nd smallest to coccyx *3 foramina* (1 vertebral foramen, 2 transverse foramen) Bifid (spinous process splits into 2)[C2-C6]

Manubrium

Top bone of the sternum. Clavicles attach here at suprasternal notch Articulates with costal cartilage of 1st and 2nd ribs

Sphenoid

Unites cranial and facial bones; articulates with almost every other bone of skull; shaped like a butterfly.

Maxilla

Upper jaw; above upper lip under nose; form floor of each orbit

Coccyx

Usually 4 fused vertebrae but can vary Aka tailbone Fuses between age 20 and 30.

Examples of irregular bones

Vertebrae, hip bones, certain facial bones.

What are the articulations between the thoracic vertebrae and ribs called?

Vertebrocostal Joints

Vomer

Vertical plate of this bone articulates with the perpendicular plate of the Ethmoid bone and forms the bony nasal septum

Costal cartilage

Where true ribs connect individually to the sternum by separate cartilaginous extensions.

Sacral Hiatus

a break in the vertebral canal of the sacrum between the laminae of the fifth sacral vertebra. Important because this is where we can administer anesthesia (caudal anesthesia), i.e. pain meds during labor

Sutural Bones

an immovable joint in the skull Small bones that form into suture lines after birth and a few months of age.

What are surface markings?

are structural features visible on the surface of bones. Each marking is structured for a specific function, such as a joint formation, muscle attachment, or passage of nerves and blood vessels.

Superior & Middle nasal concha

cause inhaled air to swirl, fling junk to mucus passageway instead of into the lungs

Sinusitis

is an inflammation of the mucous membrane of one or more paranasal sinuses.

Parts of the Axial Skeleton

skull, auditory ossicles, hyoid bone, vertebral column, sternum, and ribs

Crista Galli

triangular process, something attaches here to separate the left and right halves of the brain