Anatomy 1 - Skull and body bones and landmarks

Sternum

(Breastbone) - Flat, vertical bone at the center of your chest that protects your organs and muscles.

What are the 3 types of joints?

1. Synarthrosis 2. Amphiarthrosis 3. Diarthrosis

Bones in the Appendicular skeleton

126 bones

Bones in the Face

14 bones

How many bones does the face have?

14 bones

Bones in the Human body

206 bones

How many ribs do we have?

24 (12 on each side of the body)

How many vertebrae are in the vertebral column?

26 vertebrae

Bones in the Cranium (skull)

28 bones

Bones are in the Axial skeleton

80 bones

Ethmoid bone

A "cross-shaped" bone located in the posterior portion of the nasal cavity.

Frontal sinus

A hollow space in the bones around the nose. There are two, large frontal sinuses in the frontal bone, which forms the lower part of the forehead and reaches over the eye sockets and eyebrows.

Carotid Canal

A passage within the Petrous Temporal bone for the internal carotid artery; the carotid foramen.

Zygomatic Process

A projection of the temporal bone that forms part of the zygoma

Glabella

A single bony prominence of the frontal bone located between the superciliary arches in the inferior part of the frontal bone above the root of the nose.

Coracoid process

A thick curved process attached by a broad base to the upper part of the neck of the scapula

Ethmoid sinuses

Air cavities on each side of the nose within the ethmoid bone (a light, spongy cubical bone forming much of the walls of the nasal cavity and part of those of the orbits), with each maintaining a separate path to the nasal chamber

What is the Appendicular skeleton function?

Also contributes to the protection of nerves and blood vessels, and the pelvic bone protects the lower internal organs like the bladder and reproductive organs; Enables our body to engage in movement and allows for manipulation of the environment.

Depressions which hold teeth in place

Alveolar process

Sacrum

Bone formed from five vertebrae fused together near the base of the spinal column

Lateral Malleus

Bone on the outside of the Ankle joint, called Fibula.

Orbit area

Bony structures of the skull that house the globe, extraocular muscles, nerves, blood vessels, lacrimal apparatus, and adipose tissue.

What makes a Foramen and a Process alike?

Both of them are Bone Markings or Structural Features of bones that contribute to the overall structure and function of the Skeletal System.

Similarity between Classified and Unclassified bones

Both protect and assist the body and contribute to Hematopoiesis; both are reservoirs for minerals.

Cervical vertebrae

C1-C7

Pubic Symphysis

Cartilaginous joint known to allow some movement to facilitate childbirth and in which two pubic bones fuse together.

Acetabulum

Cup-shaped, located on the lateral face of the hipbone and articulates with the Femoral head.

Perpendicular plate (vertical cross bar) of Ethmoid bone

Divides the nasal cavity into right and left portions; located posterior of the Nasal Septum of the Nose

Parietal bone

Either of two skull bones between the frontal and occipital bones and forming the top and sides of the cranium

Tibia- medial malleolus

End of the shinbone (Tibia); bony bump on the inner side of the Ankle; forms the support for the inner side of the ankle joint. The Medial malleolus is also the attachment of the major ligament on the inner side of the ankle, called the deltoid ligament.

Most posterior projection of the skull

External occipital protuberance

What differentiates Foramen from Process?

Foramens are holes in the bone that serve as passage for nerves, blood, vessels, etc.; a Process is a projection/outgrowth or Protuberance from a bone that serves as an attachment point for muscles, tendons, or ligaments.

Occipital bone

Forms back and base of the skull

Squamous portion of Temporal bone

Forms the anterior and superior portion of the temporal bone - Thin, scale-like and translucent

Petrous portion of Temporal bone

Forms the skull base between the sphenoid and occipital bones; pyramid shaped and houses the components of the inner ear

Coccyx

Four vertebrae fused together to form the tailbone

Diarthrosis joint

Freely movable joint; allows for movement in several directions. Surrounded by a capsule which is a connective tissue membrane that contains SYNOVIAL fluid called BURSAE. It is the most numerous joints found in the body. Ex: Hip, Wrist, Elbow, Shoulder.

Sphenoid Bone (orbit)

Helps connect the neurocranium to the facial skeleton. Single bone in the midline of the cranial cavity situated posterior to the Frontal bone but anterior to the Occipital bone.

Ox coxae

Hip bone; composed of the ilium, ischium, and pubis

Only unarticulated bone in the body

Hyoid bone (Suspended in the neck by muscles and ligaments)

Synarthrosis joint

Immovable joint. Example: Cranial sutures, Sternocostal joint.

Mastoid Process of Temporal bone

Inferior projection of bone just behind the ear; site of attachment for many muscles, specifically the sternocleidomastoid muscle.

Lumbar vertebrae

L1-L5, third set of five larger vertebrae, which forms the inward curve of the spine

Acetabulum

Large socket in the pelvic bone for the head of the femur

Obturator foramen of coxal bone

Large, bilaterally paired opening of the bony pelvis. It is formed by the pubis and ischium.

Glenoid cavity/fossa

Lateral aspect of scapula which serves as point of articulation with the humerus

"Upper" jaw bone

Left and right Maxilla

Purpose of the Paranasal Sinuses

Lightens the skull and gives resonance and amplification to the voice providing buffers against trauma, and immunological defense.

Sphenoid sinuses

Located in the sphenoid bone behind the eye and under the pituitary gland

Classified Bones

Long, short, flat, and irregular bones.

Xiphoid Process

Lower, narrow portion of the sternum that starts out as cartilage and hardens as the person ages.

Major components of the Axial Skeleton

Made up of 80 bones within the central core of the body. This includes the skull (cranial and facial bones). ears, neck, back (vertebrae, sacrum, tailbone), and ribcage (sternum, ribs).

The three auditory ossicles

Malleus (hammer), incus (anvil), stapes (stirrup)

External occipital protuberance

Marks the most posterior projection of the skull

Gladiolus

Middle and largest portion of the Sternum

Nasion

Midpoint between the eyes just below the eyebrows

Ethmoid sinuses (air cells)

Nearly closed holes in the interior of the ethmoid bone.

Supraorbital Foramen

Opening above each orbit allowing blood vessels and nerves to pass

What is a Foramen?

Opening that allows the passage of structures from one region to another.

Acromion

Outward extension of the shoulder blade forming the point of the shoulder.

Forms major part of side and top of the skull

Parietal Bones

Widest part of the skull

Parietal bones

Ilium

Part of the hip bone

Glenoid Fossa/cavity

Pear-shaped, articular area found on the lateral aspect of the head of the scapula. It articulates with the head of the humerus, forming the glenohumeral (shoulder) joint.

What does the Appendicular skeleton consist of?

Pectoral girdle, upper limbs, pelvic girdle, lower limbs

What is the Axial skeleton function?

Primarily protects internal organs such as the brain, spinal cord, heart, lungs, etc.

What is a process?

Projection or outgrowth of tissue from a larger body.

Olecranon Process

Proximal articular portion of the Ulna; projection at the upper end of the ulna that forms the bony point of the elbow; (forms greater sigmoid notch which articulates with the Humerus to help Flexion and Extension of the Elbow)

Posterior/vertical portion of the Mandible

Ramus

What are the False ribs?

Ribs 8-12, lack independent cartilaginous connections to the sternum

What are True ribs?

Ribs that attach directly to the sternum (1-7)

Orbital plate

Roof of each orbit

Axis (C2)

Second cervical vertebra of the spine located below the Atlas and articulates with C1 via a superior projection called ODONTOID PROCESS (DENS) on the vertebral side. Enables head rotation.

Supports the pituitary gland

Sella turcica (superior projection of the sphenoid bone)

Cribriform plate (the horizontal cross bar) of Ethmoid bone

Separates the cranial cavity from the nasal cavity and determines the width between the eye orbits.

Where is the Hyoid bone located?

Situated at the root of the tongue in the front of the neck, and between the lower jaw. It is the largest cartilage of the larynx.

What does the Axial skeleton consist of?

Skull, vertebral column, ribs, sternum; Upper extremities (64 bones) and Lower extremities (62 bones)

Amphiarthrosis joint

Slightly movable joint (Small piece of cartilage between the bone to allow movement). Ex: joint between the pelvic bones, Intervertebral joints between the bodies of the vertebrae.

Occipital condyles of occipital bone

Small elevation on each side of the foramen magnum - articulates with the spine.

Manubrium of sternum

Superior portion of the sternum (shaped like a handle or trapezoid) Articulates with ribs 1, 2, & and clavicles. Sternocleidomastoid muscles also attach here.

Frontal sinuses

Superior to the eyes within the frontal bone. The frontal sinuses are lined with cells that make mucus to keep the nose from drying out.

Unclassified Bones

Sutural bones and sesamoid bones

Thoracic vertebrae

T1-T12; second set of 12 vertebrae; they articulate with the 12 pairs of ribs to form the outward curve of the spine

Temporal bone

The bone that forms parts of the side of the skull and floor of the cranial activity. There is a right and left temporal bone.

Ischium

The curved bone forming the base of each half of the pelvis.

Mandibular fossa (temporal)

The depression in the temporal bone into which the condyle of the mandible fits; indentation on the underside of the zygomatic process

Atlas (C1)

The first cervical vertebra of the spine located below the skull; holds the skull upright. Has a large vertebral canal and articulates with the occipital condyles of the skull. Allows for nodding or flexion of the head.

Maxillary sinuses

The largest ones located under the eyes in the maxillary bones; an infection here can cause pain in the posterior maxillary teeth

What are Floating ribs?

The last two pairs of false ribs that lack the sternal attachments

Pubis

The medial anterior portion of the pelvis

Superior and middle nasal conchae

The medial projections of the cribriform plate into the nasal cavity

Crista galli of Ethmoid bone

The most superior projection of the cribriform plate

Superciliary arch

The ridge above the eye socket indicating the location of the frontal sinus

Nasal spine

The sharp, bony projection located medially at the inferior margin of the nasal cavity.

Scapula

The shoulder blade

Lower Extremity important structures

Tibia (Medial malleolus), Fibula (Lateral malleolus), Tarsals (Calcaneus)

Acromion

Top outer edge of the scapula (shoulder blade) located above the glenohumeral joint.

Iliac crest

Upper margin of iliac bones

Why does the adult vertebral column have 26 vertebrae compared to the 33 vertebrae present at birth?

We are born with 33 individual bones that interact and connect with each other through FACETS (flexible joints). By the time we reach adulthood some vertebrae at the bottom end of the spine FUSE TOGETHER during normal growth and development.

Commonly called "the cheek bone"

Zygomatic bone