Skull and Skeletal System Overview

Questions and Answers

How many bones does the skull have?

What are the two major parts of the skeletal system?

Axial and appendicular

What are some facts about the skeletal system?

composed of bones, cartilages, joints and ligaments; 20% of body mass

What does the axial skeleton consist of?

80 bones; 3 major regions: skull, vertebral column, and thoracic cage Signup and view all the answers

What are the two types of skull bones?

Cranial bones and facial bones Signup and view all the answers

What are the cranial fossae in the base?

anterior, middle, and posterior cranial fossae Signup and view all the answers

Which lobes are located in the anterior cranial fossa?

Frontal lobes Signup and view all the answers

Which lobes are located in the middle cranial fossa?

temporal and lateral lobes Signup and view all the answers

Which part of the brain is located in the posterior cranial fossa?

cerebellum Signup and view all the answers

What is the function of the concha?

very vascular, they warm the air as you breathe Signup and view all the answers

What is the inferior nasal concha?

a standalone bone Signup and view all the answers

What is the vomer?

lowest part of the nasal septum; it is separate from the ethmoid; plow shaped Signup and view all the answers

What is the mandibular condyle?

the joint for the jaw; has the fossa as well Signup and view all the answers

How many sutures are there in the cranium?

four sutures; Squamous suture, Coronal suture, Lambdoid suture, sagittal suture Signup and view all the answers

What does the squamous suture separate?

the temporal bone from the parietal Signup and view all the answers

What does the coronal suture separate?

the frontal from the parietal Signup and view all the answers

What does the lambdoid suture separate?

the parietal and occipital Signup and view all the answers

What does the sagittal suture separate?

the left and right parietal bone Signup and view all the answers

What is the frontal sinus?

hollow chamber filled with air lined with mucous membrane and open to the outside; makes your skull lighter and your voice more pleasant Signup and view all the answers

What is sinusitis?

inflammation of sinuses because of infection Signup and view all the answers

What is the christa galli?

"cock's comb" part of the ethmoid bone; separates the two frontal lobes of the brain Signup and view all the answers

How many named openings are there in the cranium?

85 Signup and view all the answers

What is the sella turcica?

"turk's saddle"; it protects the pituitary gland, which is the body's gland master Signup and view all the answers

Which bones have perinasal sinuses?

Frontal, sphenoid, ethmoid, and maxilla Signup and view all the answers

What is the Foramen magnum?

the largest foramen in the skull Signup and view all the answers

What is the external occipital protuberance?

knot on back of head Signup and view all the answers

How many bones make up the hard palate?

4 bones; maxilla (palatine process), Maxilla, Palatine (horizontal plate) and Palatine Signup and view all the answers

What are the cribriform foramina?

olfactory, sense of smell Signup and view all the answers

How many cranial bones are there?

8; frontal bones, parietal bones (2), occipital bones, temporal bones (2), sphenoid bone, ethmoid bone Signup and view all the answers

What does the occipital bone articulate with?

1st vertebrae Signup and view all the answers

What are the four major regions of temporal bones?

Squamous, tympanic, mastoid, and petrous Signup and view all the answers

What is mastoiditis?

inflammation of the mastoid process when it becomes infected Signup and view all the answers

What is the sphenoid bone?

bat or butterfly shaped; keystone bone; Greater wing, lesser wing, and pterygoid process Signup and view all the answers

What is the ethmoid bone?

deepest skull bone; superior part of nasal septum; contributes to medial wall of orbits; christa galli for dural attachment Signup and view all the answers

How many facial bones are there?

14; mandible, maxillary (2), zygomatic, nasal, lacrimal (2), palatine (2), vomer, inferior nasal conchae (2) Signup and view all the answers

What muscles are in the neck?

you have a TON of muscles in your neck; they attach to your hyoid bone Signup and view all the answers

What is the hyoid bone?

sesamoid bone imbedded in neck muscles; adds stability to the neck; forensic effect: When one is strangled or throat is sliced, it usually breaks; movable base for tongue Signup and view all the answers

What is the mandible?

lower jaw; largest strongest bone of the face; temporomandibular joint; the only freely movable joint in skull Signup and view all the answers

What is the maxillary?

medially fused to form upper jaw and central portion of facial skeleton; keystone bones, and maxillary sinuses Signup and view all the answers

What are keystone bones?

articulates with all other facial bones except mandible Signup and view all the answers

What are zygomatic bones?

cheekbones; inferolateral margins of orbits Signup and view all the answers

What is the lacrimal fossa?

houses lacrimal sac (tear duct) Signup and view all the answers

How many bones are in the orbits?

7; frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal, and ethmoid Signup and view all the answers

How many bones are in the nasal cavity?

4; ethmoid, palatine, maxillary, inferior nasal conchae Signup and view all the answers

What are the nasal septum bones?

3; perpendicular plate of ethmoid, vomer, anterior septal cartilage Signup and view all the answers

What is the vertebral column?

transmits weight of trunk to lower limb, surrounds and protects spinal cord; 5 major regions with 26 irregular bones in adults, 33 in infants Signup and view all the answers

How many cervical vertebrae are there?

7; C1-C7: concave Signup and view all the answers

How many thoracic vertebrae are there?

12; T1-T12: convex Signup and view all the answers

How many lumbar vertebrae are there?

5; L1-L5: concave; help us walk upright Signup and view all the answers

How many sacral vertebrae are there?

5; vertebrae are fused in adults; convex Signup and view all the answers

How many bones make up the coccyx?

4; fused vertebrae in adults Signup and view all the answers

What is scoliosis?

lateral curvature of the spine; more common in females Signup and view all the answers

What is kyphosis?

hunchback Signup and view all the answers

What is lordosis?

swayback; can be exaggerated by pregnancy or "beer" belly Signup and view all the answers

What ligaments are found from neck to sacrum?

anterior and posterior longitudinal ligaments Signup and view all the answers

What ligaments connect adjacent vertebrae?

ligamentum flavum Signup and view all the answers

What ligaments connect each vertebra to those above and below?

short ligaments Signup and view all the answers

What is the nucleus pulposus?

inner gelatinous nucleus; gives disc its elasticity and compressibility Signup and view all the answers

What is the anulus fibrosis?

outer collar composed of collagen and fibrocartilage Signup and view all the answers

What is the general structure of vertebrae?

body or centrum, vertebral arch, vertebral foramina (vertebral canal) Signup and view all the answers

What is a herniated disc?

herniation occurs when the anulus fibrosis is thinned and broken; the nucleus pulposus pushes against the spinal cord Signup and view all the answers

What cervical vertebra turns the neck?

Atlas Signup and view all the answers

What cervical vertebra limits turning range?

Axis Signup and view all the answers

What is the dens?

fuses with the axis; tooth-like; used in hangings Signup and view all the answers

How many processes do vertebrae have?

7; spinous, transverse, superior articular (2), inferior articular (2) Signup and view all the answers

What is the vertebra prominens?

C7 Signup and view all the answers

What is the thoracic cage?

rib cage; flexible with costal cartilage; has 12 ribs (7 true, 5 false) Signup and view all the answers

What allows for movement in ribs?

intercostal spaces Signup and view all the answers

What attaches ribs to vertebrae?

Ligaments Signup and view all the answers

What are the bones of the sternum?

manubrium (articulates with ribs 1 and 2), body (articulates with ribs 2-7), and xiphoid process (ossifies at age 40) Signup and view all the answers

What is the pectoral girdle composed of?

4 bones; 2 clavicles and 2 scapulae Signup and view all the answers

What are the clavicles?

collarbones; cone-shaped sternal end articulates with sternum medially Signup and view all the answers

What are the scapulae?

between ribs 2-7; suprascapular notch (only notch) Signup and view all the answers

What is the coronoid process on the mandible?

Coranoid Signup and view all the answers

What is the coracoid process on the scapula?

Coracoid Signup and view all the answers

How many bones are in the upper limb?

30; Arm 1, Forearm 2, hand 27 Signup and view all the answers

What bone is in the arm?

Humerus Signup and view all the answers

What bones are in the forearm?

Radius (smaller bone on side with thumb) and Ulna (larger bone on the pinkie side) Signup and view all the answers

How many wrist bones are there?

8 carpal bones; Scaphoid, Lunate, Triquetral, Pisiform, Trapezium, Trapezoid, Capitate, Hamate Signup and view all the answers

What does the radius articulate with?

Capitulum; it helps you rotate your arm Signup and view all the answers

What does the ulna articulate with?

Trochlea; it helps you flex and extend your arm Signup and view all the answers

How many condyles are in the humerus?

2; Trochlea and capitulum Signup and view all the answers

What are some facts about the elbow joint?

when you face your palm down, the bones are no longer parallel Signup and view all the answers

What is the interosseous membrane?

holds the bones together, but allows flexibility; made of connective tissue Signup and view all the answers

What is the metacarpus?

palm; 5 bones Signup and view all the answers

How many phalanges are in each hand?

14 in each hand; each finger has 3 phalanx: distal, middle, and proximal; the thumb has no middle phalanx Signup and view all the answers

What is the pelvic girdle composed of?

Os coxae; each side; each coxae made of 3 fused bones, solid Signup and view all the answers

What is the ilium?

flared part of the pubic bone Signup and view all the answers

What is the pubis?

or pubic bone Signup and view all the answers

What is the ischium?

lowest part of the pelvis; what you sit on Signup and view all the answers

What are the landmarks for giving injections?

iliac crest and anterior superior spine Signup and view all the answers

What is the sacroiliac joint?

joins the sacrum to the ilium; when you are pregnant, the hormones loosen the os coxae and the pubic symphysis Signup and view all the answers

What are the bony pelvis bones?

3; coxal bones (3 fused bones), sacrum, and coccyx Signup and view all the answers

What does the sacrum articulate with?

the articular surface of the ilium Signup and view all the answers

Where do the pubis bones join?

at the pubic symphysis joint Signup and view all the answers

What defines the birth canal?

the true pelvis, inferior to the pelvic brim Signup and view all the answers

What are the characteristics of the female pelvis?

tilted forward, adapted to childbearing; broad, shallow; pubic angle lightweight, 80-90◦ Signup and view all the answers

What are the characteristics of the male pelvis?

tilted less, heavier bones; pubic arch is longer and closer; pubic angle is 50-60◦ Signup and view all the answers

What is the acetabulum?

"vinegar cup" or the hip socket Signup and view all the answers

What is the ischial spine?

important in childbirth; you can tell how far apart they are and how much room you have Signup and view all the answers

Study Notes

Skull and Skeletal System

The skull contains 22 bones and is divided into cranial and facial categories.
The skeletal system comprises bones, cartilages, joints, and ligaments, accounting for 20% of body mass.
The axial skeleton consists of 80 bones, organized into three main regions: skull, vertebral column, and thoracic cage.

Skull Bones

Skull bones are classified into cranial bones and facial bones.
The cranial fossa is divided into three sections: anterior, middle, and posterior, supporting different brain lobes.
Key structures within the skull include the mandibular condyle for jaw movement and 85 named openings in the cranium for nerves and blood vessels.

Sinuses and Other Structures

The frontal sinus helps lighten the skull and improve voice quality, while sinusitis refers to inflammation due to infection.
The cribriform foramina are involved in the olfactory sense, facilitating smell.

Vertebral Column

The vertebral column consists of 26 irregular bones in adults, organized into five regions: cervical, thoracic, lumbar, sacral, and coccyx.
Cervical vertebrae (7) are concave, thoracic vertebrae (12) are convex, and lumbar vertebrae (5) assist in upright walking. In total, infants have 33 vertebrae.

Spinal Disorders

Scoliosis refers to lateral curvature, more common in females.
Kyphosis is characterized by a hunchback appearance, while lordosis results in a swayback posture.

Ligaments and Intervertebral Discs

Vertebral stability is supported by anterior and posterior longitudinal ligaments, ligamentum flavum, and short ligaments between adjacent vertebrae.
Intervertebral discs contain the nucleus pulposus (gelatinous inner part) and the anulus fibrosus (collagen outer layer).

Pelvic Girdle

The pelvic girdle (os coxae) consists of three fused bones and provides stability and attachment for the lower limbs.
Structural anatomy includes the ilium, pubis, and ischium, with key landmarks for injections being the iliac crest and anterior superior spine.

Gender Differences in Pelvis

The female pelvis is more adapted to childbearing, featuring a broader and shallower shape, while the male pelvis is heavier with a higher pubic angle.
The acetabulum serves as the hip socket, crucial for joint stability.

Upper and Lower Limbs

The upper limb consists of 30 bones, including the humerus in the arm and the radius and ulna in the forearm.
Phalanges total 14 in each hand; the thumb lacks a middle phalanx.
The pectoral girdle, comprising two clavicles and two scapulae, facilitates arm movement and stabilization.

Joint Facts

Key elbow joint interactions involve the radius articulating with the capitulum and the ulna with the trochlea for flexion and extension movements.

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Description

This quiz covers the anatomy of the skull and skeletal system, including the classification of skull bones into cranial and facial categories, as well as the structure and function of the axial skeleton. You will also learn about the importance of sinuses and openings in the skull. Test your knowledge of these fundamental concepts in human anatomy.