Skeletal System (Questions - EXAM #2) Flashcards
What are the two types of bone tissue?
Compact bone and spongy bone.
What is the structural unit of compact bone?
The osteon.
Name the components of an osteon.
Lamellae, lacunae (with osteocytes), canaliculi, central canal, and perforating canal.
What is the purpose of canaliculi in compact bone?
They connect osteocytes to each other and to the blood supply.
What structure in spongy bone contains bone marrow?
Spaces within trabeculae.
In anatomical position, how are the feet, face, and palms oriented?
Feet, face, and palms are forward.
What directional terms describe “toward the body’s midline” and “away from the midline”?
Medial (toward midline) and lateral (away from midline).
What are the two divisions of the skeletal system?
The axial skeleton and the appendicular skeleton.
Which bones form the axial skeleton?
Skull, hyoid bone, vertebral column, and thoracic cage.
What structures are included in the appendicular skeleton?
Pectoral and pelvic girdles, upper and lower limbs.
What are the three main bone groupings of the skull?
Cranium, facial bones, and auditory ossicles.
How many cranial bones are there, and name one.
There are eight cranial bones, one example is the frontal bone.
Which two bones form the hard palate?
The palatine bones and maxillae.
Does the hyoid bone articulate with other bones?
No, it does not articulate with other bones.
What is the function of the hyoid bone?
It assists in swallowing and attaches muscles of the tongue and neck.
How many vertebrae are in the vertebral column, and how are they divided?
26 vertebrae divided into cervical, thoracic, lumbar, sacrum, and coccyx regions.
Which vertebrae allows the “yes” nodding motion?
C1 (Atlas) allows the “yes” nodding motion.
Which vertebra has a dens for the “no” rotation motion?
C2 (Axis) has a dens (odontoid process) for rotation.
What are the three parts of the sternum?
Manubrium, body, and xiphoid process.
How many pairs of ribs are there, and which are considered “floating ribs”?
12 pairs of ribs; the 11th and 12th pairs are floating ribs.
What two bones make up the pectoral girdle?
Clavicle and scapula.
What part of the scapula articulates with the head of the humerus?
The glenoid cavity.
What three bones form each hip bone (os coxae)?
Ilium, ischium, and pubis.
What joint connects the pubic bones at the front of the pelvis?
The pubic symphysis.
What bones make up the arm and forearm?
Humerus, radius (lateral), and ulna (medial).
What bones make up the thigh and leg?
Femur, patella, tibia (medial), and fibula (lateral).
What is the shaft of a long bone called?
Diaphysis.
Where does bone growth in length occur?
At the epiphyseal plate.
What is the function of the medullary cavity?
It contains red marrow in children and yellow marrow in adults.
What type of cartilage covers the ends of long bones at joints?
Articular cartilage (hyaline cartilage).
What defines an articulation or joint in the skeletal system?
It’s the point of contact between two or more bones.
What are the two main classifications of joints?
Structural and functional classifications.
On what two factors is structural classification of joints based?
Presence or absence of a joint cavity and the type of connective tissue joining the bones.
What are the three types of structural joints?
Fibrous, cartilaginous, and synovial joints.
Do fibrous joints have a joint cavity?
No, they do not have a joint cavity.
What type of tissue connects bones in fibrous joints?
Fibrous connective tissue.
Give an example of a fibrous joint.
Sutures in the skull.
What connects bones in cartilaginous joints?
Cartilage.
Name an example of a cartilaginous joint.
They have a joint cavity and allow free movement.
What are synovial joints known for?
They have a joint cavity and allow free movement.
What is the function of the articular cartilage in synovial joints?
It reduces friction between articulating bones.
What fills the joint cavity in synovial joints?
Synovial fluid.
Describe the layers of the articular capsule in synovial joints.
The outer fibrous capsule attaches to the periosteum, and the inner synovial membrane secretes synovial fluid.
What type of movement is allowed by plane or gliding joints?
Sliding movements along flat surfaces.
Give an example of a plane or gliding joint.
The sacroiliac joint.
What structure characterizes a hinge joint?
It has concave and convex surfaces that allow bending and straightening movements.
Name two examples of hinge joints.
Elbow and knee joints.
What is a pivot joint, and provide an example.
A joint with a projection fitting into a ring, such as the dens (on axis) in the atlas.
What type of joint allows the greatest range of movement?
The ball and socket joint.
Give two examples of ball and socket joints.
The shoulder joint (humerus in the glenoid fossa) and hip joint (femur in the acetabulum).
What is functional classification of joints based on?
The degree of movement allowed.
What are the three types of functional joints?
Synarthrotic, amphiarthrotic, and diarthrotic.
Define a synarthrotic joint and give an example.
A joint that is immovable, such as the sutures in the skull.
What is an amphiarthrotic joint, and give an example.
A slightly movable joint, like the pubic symphysis.
Describe a diarthrotic joint and provide an example.
A freely movable joint, such as the hip or shoulder.
