Skeletal System - (Fill in the Blank)

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

The ______ bone forms the greater portion of the sides and roof of the cranial cavity.

parietal

The ______ suture usually disappears between the ages of 6 and 8.

metopic

The posterior part and most of the base of the cranium is formed by the ______ bone.

occipital

The temporomandibular joint is formed by the mandibular fossa and the ______.

articular tubercle Signup and view all the answers

The ______ bone protects the upper entry to the nasal cavity.

ethmoid Signup and view all the answers

Lacrimal bones are the smallest bone of the face, located posterior and lateral to the ______ bone.

nasal Signup and view all the answers

The ______ bone forms the posterior portion of the hard palate.

palatine Signup and view all the answers

A typical feature of skull anatomy is the presence of ______, which are immovable joints that hold most skull bones together.

sutures Signup and view all the answers

The sagittal suture connects the two ______ bones.

parietal Signup and view all the answers

The ______ bone forms the inferior portion of the bony nasal septum.

vomer Signup and view all the answers

The ______ is the largest and strongest facial bone in the human body.

mandible Signup and view all the answers

The hard palate separates the nasal cavity from the ______ cavity.

oral Signup and view all the answers

Fontanels serve as spacers for the growth of neighboring skull bones and provide some flexibility to the fetal ______.

skull Signup and view all the answers

The temporomandibular joint is formed by the condylar process articulating with the ______ fossa of the temporal bone.

mandibular Signup and view all the answers

The paired anterolateral fontanels are located among the frontal, parietal, temporal and ______ bones.

sphenoid Signup and view all the answers

The unpaired posterior fontanel is smaller than the anterior fontanel and is located between the two parietal bones and the ______ bone.

occipital Signup and view all the answers

The two subtypes of fibrous joints are ______ and syndesmoses.

sutures Signup and view all the answers

The ______ joint allows for movement between the first rib and the manubrium of the sternum.

synovial Signup and view all the answers

The ______ cartilage serves as the growth center during endochondral bone formation.

epiphyseal Signup and view all the answers

In a symphysis, the ends of articulating bones are covered with ______ cartilage.

hyaline Signup and view all the answers

The fibrous cartilage that connects bones in a symphysis joint is a broad, flat ______.

disc Signup and view all the answers

The ______ ligament and membrane allow limited movement between certain bones.

interosseous Signup and view all the answers

Movements in synovial joints can range from slightly movable to ______.

freely movable Signup and view all the answers

Articular ______ is a type of hyaline cartilage that covers the ends of bones in synovial joints.

cartilage Signup and view all the answers

The ______ joint reduces friction between bones during movement and helps absorb shock.

pivot/trochoid Signup and view all the answers

The ______ joint is characterized by a convex oval-shaped projection fitting into an oval-shaped depression.

ellipsoid/condylar Signup and view all the answers

The 8th, 9th, and 10th pairs of ribs attach to the cartilage of the ______ rib.

7th Signup and view all the answers

The ______ joint consists of the ball-like surface of one bone fitting into a cuplike depression of another bone.

ball and socket Signup and view all the answers

In a ______ joint, the articular surface of one bone is saddle-shaped, allowing for back-and-forth and side-to-side movements.

saddle/sellar Signup and view all the answers

The pectoral girdle does not articulate with the axial skeleton; it is held by a group of large ______.

muscles Signup and view all the answers

The ______ joint has a convex surface of one bone fitting into the concave surface of another bone.

hinge Signup and view all the answers

The most frequently fractured bone in the body is the ______.

humerus Signup and view all the answers

The ______ joint is formed by the combined hinge and plane joint structure.

temporomandibular Signup and view all the answers

The ______ is located on the medial aspect of the forearm and is longer than the radius.

ulna Signup and view all the answers

The articular capsule encloses the ______.

articular cavity Signup and view all the answers

The proximal radioulnar joint is formed by the radial notch and the head of the ______.

radius Signup and view all the answers

The ______ joint allows for flat or slightly curved surfaces to move in multiple directions.

plane/arthrodial Signup and view all the answers

The metacarpals are considered the longest bones in the ______.

hand Signup and view all the answers

The intercarpal joint involves the articulation between ______.

carpals Signup and view all the answers

The pelvic girdle consists of two ______ bones.

hip Signup and view all the answers

The ______ forms the base of the skeleton for the upper limbs.

humerus Signup and view all the answers

The small, pea-shaped carpal bone is called the ______.

pisiform Signup and view all the answers

Study Notes

Cranial Bones

Frontal bone: Forms the forehead and roof of the nasal cavity.
Parietal bone: Forms the majority of the sides and roof of the cranium.
- The inner surface has protrusions and depressions to accommodate blood vessels supplying the dura mater (brain covering).
Occipital bone: Forms the posterior part and most of the base of the cranium.
Temporal bone: Forms the inferior lateral aspects of the cranium and part of the cranial floor.
- Temporomandibular joint: Formed by the articulation of the mandibular fossa and articular tubercle with the mandible.
Sphenoid bone: Wedge-shaped, located at the middle part of the skull.
- Keystone of the cranial floor: Articulates with all other cranial bones.
Ethmoid bone: Delicate bone with a spongy appearance, anterior to the cranial floor.
- Protects the upper entry to the nasal cavity.

Facial Bones

Nasal bone: Paired, small, flattened, rectangular bones that form the bridge of the nose.
Lacrimal bone: Paired, thin, smallest bone of the face, posterior and lateral to the nasal bone.
- Lacrimal fossa: Vertical tunnel housing the lacrimal sac (collects tears and passes them to the nasal cavity).
Palatine bone: Two L-shaped bones forming the posterior portion of the hard palate.
Inferior nasal concha: Located inferior to the middle nasal concha, not part of the ethmoid bone.
Vomer: Triangular bone on the floor of the nasal cavity.
- Forms the inferior portion of the bony nasal septum.
Maxillae: Upper jawbone, part of the cranium.
- Hard palate: Bony roof of the mouth, separating the nasal cavity from the oral cavity.
- Infraorbital foramen: Passage for infraorbital blood vessels and nerves, maxillary division of the trigeminal nerve.
Zygomatic bone: Cheekbones, temporal process projects posteriorly and articulates with the zygomatic process to form the zygomatic arch..
Mandible: Lower jawbone, largest and strongest facial bone.
- Temporomandibular joint: Condylar process articulates with the mandibular fossa and the articular tubercle of the temporal bone.

Sutures

Immovable joints: Holds most skull bones together.
Four prominent sutures:
- Coronal suture: Joins the frontal and parietal bones.
  - Bregma: Junction of coronal and sagittal sutures.
- Sagittal suture: Joins the two parietal bones.
  - Fontanels: Soft spots that allow for skull growth.
- Lambdoid suture: Joins the two parietal and occipital bones.
  - Lambda: Junction of the sagittal and occipital sutures.
- Squamous sutures: Two parietal bones and two temporal bones.

Fontanels

Incompletely developed cranial bones: Act as spacers for the growth of neighboring skull bones, providing flexibility to the fetal skull during birth.
Six fontanels:
- Anterior fontanel (unpaired): Largest, diamond shape, located at the midline along the two parietal bones and the frontal bone. Closes 18-24 months after birth.
- Posterior fontanel (unpaired): Smaller than the anterior fontanel, located at the midline between the two parietal bones and the occipital bone. Closes about 2 months after birth.
- Anterolateral fontanels/sphenoid fontanels (paired): Small and irregular, located among the frontal, parietal, temporal, and sphenoid bones.

Appendicular Skeleton

Pectoral/Shoulder Girdle

Connects the upper limbs to the axial skeleton.
Does not directly articulate with the axial skeleton, but is held in place by muscles.
Clavicle: S-shaped bone, medial half is convex anteriorly, lateral half is concave anteriorly.
- Most frequently fractured bone in the body.
- The clavicular mid region is the weakest point.

Upper Extremity

Contains 30 bones on one side (60 for both sides).
Humerus (1): Bone of the arm.
- Forms the glenohumeral joint with the scapula.
Radius and ulna (2): Bones of the forearm.
Carpals (8), metacarpals (5), and phalanges (14): Bones in the hand, wrist.

Humerus

Trochlea and coronoid process (anterior): With the olecranon (posterior), forms the elbow joint.
Coronoid fossa: Part of the humerus involved in elbow joint formation.

Ulna

Located on the medial aspect.
Longer than the radius.
"Pinky on the Ulnar side."
Olecranon: Forms the elbow.
Trochlear notch: With the olecranon and coronoid fossa (part of humerus), forms the elbow joint.

Radius

Smaller bone of the forearm, located on the lateral side.
Proximal radioulnar joint: Articulation between the radial notch and the head of the radius.
Distal radioulnar joint: Articulation between the head of the ulna and the ulnar notch.
Allows forearm pronation and supination.

Carpals

Bones of the wrist, proximal region of the hand.
Intercarpal joint: Articulation between the carpal bones.
Proximal row:
- Scaphoid: Boat-shaped.
- Lunate: Moon-shaped.
- Triquetrum: Triangular-shaped.
- Pisiform: Pea-shaped.
Distal row:
- Trapezium: Four-sided, no sides parallel.
- Trapezoid: Four-sided, two sides parallel.
- Capitate: Head-shaped.
- Hamate: Hooked.

Metacarpals, Phalanges/Phalanx/Digit

Metacarpals: Longest bones in the hand.
Phalanges:
- Proximal phalanges:
- Middle phalanges:
- Distal phalanges:
Thumb (pollex): Has two phalanges.

Pelvic Girdle

Consists of two hip bones/coxal bones/pelvic bones (aka os coxa).
These bones form the pelvic girdle.

Lower Extremities

Contains 40 bones on one side (80 for both sides).
Femur: Thighbone; longest and strongest bone in the body
- Forms the hip joint with the acetabulum (pelvic girdle) and the knee joint with the tibia.
Tibia (shinbone): Medial bone in the lower leg.
- Forms the knee joint with the femur and the ankle joint with the talus.
Fibula: Lateral bone in the lower leg.
- Does not articulate with the femur.
- Forms the ankle joint with the talus.
Tarsals (7): Bones of the ankle, proximal region of the foot.
Metatarsals (five): Bones of the foot.
Phalanges (14): Bones of the toes.
- The big toe is the hallux and has two phalanges.

Joints

Types of Joints

Fibrous joints: Characterized by dense irregular connective tissue (collagen fibers). Movements vary from immovable to slightly movable.
- Sutures: Found only on the skull, with a thin layer of dense irregular connective tissue.
- Syndesmosis: Has a greater articulating surface and more dense connective tissue than a suture.
  - Interosseous ligament (AnTiFi) and interosseous membrane (radioulna): Permit limited movement.
Cartilaginous joints: Characterized by hyaline cartilage.
- Synchondroses: Hyaline cartilage connecting bones (costal cartilages – 1st rib and manubrium of sternum).
  - Epiphyseal cartilage: Hyaline cartilage growth centers used during endochondral bone formation, not associated with movement (epiphyseal plate).
- Symphyses: Ends of bones covered with hyaline cartilage, connected by a flat disc of fibrous cartilage (pubic symphysis).
Synovial joints: Characterized by an articular cavity (a space between articulating bones). Movements range from slightly movable to freely movable.
- Bones are covered with hyaline cartilage, and the joint is enclosed by an articular capsule.
- Synovial fluid: Lubricates the joint, reducing friction and absorbing shocks.

Types of Synovial Joints

Plane/Arthrodial joint: Flat or slightly curved surfaces.
- Biaxial, triaxial/multiaxial.
- Examples: Intercarpal joints, sternocostal joints.
Hinge joint: Convex surface of one bone fits into the concave surface of another bone.
- Uniaxial.
- Examples: Elbow, ankle.
Pivot/Trochoid joint: Rounded or pointed surface of one bone articulates with a ring formed by another bone and ligament.
- Uniaxial
- Examples: Atlanto-axial joint (allows "no" movement), radioulnar joint.
Ellipsoid/Condylar joint: Convex oval-shaped projection of one bone fits into an oval-shaped depression on another bone.
- Biaxial.
- Examples: Radiocarpal joint, metacarpophalangeal joint (MCP).
Saddle/Sellar joint: Articular surface of one bone is saddle-shaped, and the other bone fits into this "saddle."
- Biaxial, plus limited circumduction.
- Examples: Carpometacarpal joint (CMC) of the thumb, sternoclavicular joint.
Ball and socket/Spheroidal joint: Ball-like surface of one bone fits into a cuplike depression on another bone.
- Triaxial.
- Examples: Glenohumeral joint, hip joint.

Temporomandibular Joint

A combined hinge and plane joint formed by the condylar process of the mandible and the mandibular fossa and articular tubercle of the temporal bone.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz provides an in-depth look at various bones and features of the skull. Test your knowledge on the anatomical structures, sutures, and joints that make up the cranial and facial skeleton. Perfect for students of anatomy or those preparing for exams in human biology.