Lab Exam #2 ALL TTK

Skull Anatomy

Fontanelles

Fontanelles are soft, membranous gaps between the cranial bones in infants, allowing for growth of the brain and skull. They typically ossify as the child ages.

• Anterior fontanelle: Largest, located at the junction of the frontal and parietal bones.

• Posterior fontanelle: Smaller, located at the junction of the parietal and occipital bones.

Cranial Sutures

Sutures are immovable joints between the bones of the skull, providing stability and protection for the brain.

• Frontal/Coronal suture: Between frontal and parietal bones.

• Sagittal suture: Between the two parietal bones.

• Squamous suture: Between parietal and temporal bones.

• Lambdoid suture: Between parietal and occipital bones.

Cranial Fossae

The cranial fossae are depressions in the floor of the cranial cavity that accommodate different parts of the brain.

• Anterior cranial fossa: Houses the frontal lobes.

• Middle cranial fossa: Houses the temporal lobes.

• Posterior cranial fossa: Contains the cerebellum and brainstem.

Cranial Bones (8)

The cranium consists of eight bones that protect the brain and form the structure of the head.

• Frontal Bone (1): Forms the forehead; contains sinuses.

• Parietal Bones (2): Form the sides and roof of the cranium.

• Temporal Bones (2):

  • Mandibular fossa

  • External acoustic meatus

  • Zygomatic process

  • Mastoid process

  • Styloid process

  • Internal acoustic meatus

• Occipital Bone (1): Contains occipital condyles for articulation with the vertebral column.

• Sphenoid Bone (1): Contains sella turcica (pituitary gland location) and sinus.

• Ethmoid Bone (1):

  • Cribriform plate (with olfactory foramen)

  • Perpendicular plate

  • Crista galli

  • Sinus

Cranial Foramen and Canals

Foramina and canals are openings in the skull that allow passage of nerves and blood vessels.

• Foramen magnum

• Superior orbital fissure

• Inferior orbital fissure

• Foramen rotundum

• Foramen ovale

• Foramen spinosum

• Foramen lacerum

• Carotid canal

• Jugular foramen

Facial Bones (14)

The facial skeleton consists of fourteen bones that form the structure of the face and support sensory organs.

• Nasal Bones (2)

• Lacrimal Bones (2): Contain the fossa for the lacrimal sac.

• Maxillary Bones (2): Contain palatine process and sinus.

• Zygomatic Bones (2): Form the cheekbones; include temporal process.

• Palatine Bones (2)

• Vomer (1)

• Inferior Nasal Conchae (2)

• Mandible (1):

  • Ramus

  • Angle

  • Condylar process

Hyoid Bone

The hyoid bone is a U-shaped bone in the neck that supports the tongue and is not directly attached to other bones.

Composite Structures of Skull

• Zygomatic Arch: Formed by the temporal process of the zygomatic bone and the zygomatic process of the temporal bone.

• Nasal Septum: Formed by the perpendicular plate of the ethmoid bone and the vomer.

• Orbit of Eye: Composed of several bones including frontal, sphenoid, ethmoid, lacrimal, maxillary, zygomatic, and palatine bones.

Vertebral Column / Spine of Axial Skeleton

Vertebrae

The vertebral column consists of 33 vertebrae, divided into regions:

• Cervical (C1–C7)

  • Transverse foramen

  • Atlas (C1): Supports the skull

  • Axis (C2): Contains the odontoid process (dens)

• Thoracic (T1–T12)

• Lumbar (L1–L5)

• Sacrum

• Coccyx

Parts of Generic Vertebrae

• Vertebral body

• Vertebral arch (laminae, pedicles)

• Spinous process

• Transverse processes

• Articular processes (superior & inferior)

Intervertebral Foramen

Openings between adjacent vertebrae for the passage of spinal nerves.

Intervertebral Disc

• Annulus fibrosus: Outer ring of fibrocartilage

• Nucleus pulposus: Gel-like center

Ligaments of the Spine

• Anterior longitudinal ligament

• Posterior longitudinal ligament

• Ligamentum flavum

• Ligamentum nuchae

Normal & Abnormal Spinal Curvatures

• Lordosis: Exaggerated lumbar curve

• Kyphosis: Exaggerated thoracic curve

• Scoliosis: Lateral curvature of the spine

The Thoracic Cage

Sternum

• Manubrium

• Body (gladiolus)

• Xiphoid process

Costals (Ribs)

• True ribs: Directly attached to sternum (1–7)

• False ribs: Indirectly attached or not attached to sternum (8–12)

• Costals 8–12 are vertebro-chondral

Bones of the Lower Extremities: Appendicular Skeleton

Pelvic Girdle

• Coxal bone (hip bone)

• Ilium (regional division)

• Ischium (regional division)

• Pubis (regional division)

• Pelvis: Male vs. female differences (male pelvis is more robust, female pelvis is wider for childbirth)

Lower Limb Bones

• Femur

• Tibia

• Fibula

• Patella (sesamoid bone)

• Metatarsals (1–5)

• Tarsals:

  • Calcaneus

  • Talus

  • Navicular

  • Cuboid

  • Cuneiforms (medial, intermediate, lateral)

• Phalanges (1–5): Proximal, middle (except hallux), distal

Shoulder (Pectoral) Girdle

• Clavicle

• Scapula

• Humerus

• Radius

• Ulna

• Metacarpals (1–5): Proximal, middle (except for pollex), distal

Carpal Bones

• Scaphoid

• Lunate

• Triquetrum (triquetral bone)

• Pisiform

• Hamate

• Capitate

• Trapezoid

• Trapezium

Phalanges (1–5)

• Proximal

• Middle (except for pollex)

• Distal

Movements

Movements in Sagittal Plane

• Flexion

• Extension

• Plantar flexion

• Dorsiflexion

Movements in Frontal Plane

• Abduction

• Adduction

• Lateral flexion

• Inversion

• Eversion

Movements in Transverse Plane

• Rotation

• Supination

• Pronation

• Horizontal abduction

• Horizontal adduction

• Retraction

• Elevation

• Depression

• Opposition

• Circumduction

Classification of Joints

Functional Classification

• Diarthrosis: Freely movable joints

• Amphiarthrosis: Slightly movable joints

• Synarthrosis: Immovable joints

Structural Classification

• Synovial:

  • Joint cavity

  • Synovial fluid

  • Articular capsule

  • Fibrous capsule

  • Synovial membrane

  • Articular cartilage

  • Reinforcing ligaments

• Fibrous

• Cartilaginous

Major Joints and Ligaments

Knee Joint (Femoro-tibial Joint)

• Lateral (fibular) collateral ligament

• Medial (tibial) collateral ligament

• Anterior cruciate ligament

• Posterior cruciate ligament

• Lateral meniscus

• Medial meniscus

Shoulder (Pectoral) Girdle

• Clavicle: Sternal (medial) end, acromial (lateral) end

• Scapula: Glenoid fossa, supraspinous fossa, infraspinous fossa, subscapular fossa, coracoid process, acromion process, spine, superior angle, inferior angle, medial border, lateral border, supraglenoid tubercle, infraglenoid tubercle

• Humerus: Head, greater tubercle, lesser tubercle, intertubercular sulcus (bicipital groove), deltoid tuberosity, medial epicondyle, lateral epicondyle, trochlea, capitulum, lateral supracondylar ridge, olecranon fossa

• Radius: Head, radial tuberosity, styloid process

• Ulna: Olecranon process, coronoid process, trochlear notch

Pelvic Girdle and Lower Limb Bones

Pelvic Girdle

• Coxal bone

• Ilium: Iliac crest, iliac fossa, greater sciatic notch, anterior superior iliac spine, anterior inferior iliac spine, posterior superior iliac spine, posterior inferior iliac spine

• Auricle (articular surface for sacrum)

• Ischium: Ramus, ischial tuberosity, lesser sciatic notch, ischial spine

• Pubis: Pubis tuberosity, ramus (superior & inferior)

• Acetabulum

• Obturator foramen

Femur

• Head

• Greater trochanter

• Lesser trochanter

• Gluteal tuberosity

• Linea aspera

• Lateral epicondyle

• Medial epicondyle

• Lateral condyle

• Medial condyle

• Intercondylar fossa

• Adductor tubercle

Summary Table: Cranial Bones and Key Features

Bone	Number	Key Features
Frontal	1	Sinuses
Parietal	2	Forms roof and sides of cranium
Temporal	2	Mandibular fossa, acoustic meatus, zygomatic process, mastoid process, styloid process
Occipital	1	Occipital condyles
Sphenoid	1	Sella turcica, sinus
Ethmoid	1	Cribriform plate, perpendicular plate, crista galli, sinus

Summary Table: Functional Classification of Joints

Type	Mobility	Example
Diarthrosis	Freely movable	Shoulder, knee
Amphiarthrosis	Slightly movable	Intervertebral discs
Synarthrosis	Immovable	Sutures of skull

Key Equations

• Range of Motion (ROM) is measured in degrees and depends on joint type and ligament flexibility.

• Torque (T) produced by muscles at a joint: $T = F \times r$ where F is force and r is the lever arm distance.

Additional info: Some anatomical terms and features have been expanded for clarity and completeness. The tables summarize key bones and joint classifications for quick review.