Anatomy Lab 3

What type of cells are embedded in cartilage matrix?

Chondrocytes

In what small cavities do chondrocytes reside?

Lacunae

Is cartilage vascular or avascular?

Avascular (contains no blood vessels)

How does the avascular nature of cartilage affect its healing?

Regeneration is poor

What feature chiefly determines the type of cartilage present?

The type and amount of fibers in the matrix

Are fibers microscopically visible in hyaline cartilage?

No, they are not visible

Give three typical locations of hyaline cartilage.

Embryonic skeleton, ends of long bones, and costal cartilages (also nose, trachea, larynx)

Which fiber type predominates in elastic cartilage?

Elastic fibers

Primary function of elastic cartilage?

Maintains shape while allowing great flexibility

Where can elastic cartilage be found?

External ear (pinna) and epiglottis

Which fiber type predominates in fibrocartilage?

Thick collagen fibers

Main functional advantage of fibrocartilage?

Tensile strength and ability to absorb compressive shock

List three locations of fibrocartilage.

Intervertebral discs, pubic symphysis, and menisci of the knee

Which cells occupy lacunae in bone tissue?

Osteocytes

Describe the bone matrix.

Hard, calcified, with no visible collagen fibers

What is the functional unit of compact bone?

Osteon (Haversian system)

What structure runs through the center of each osteon?

Central (Haversian) canal containing blood vessels

Define lamellae in bone.

Concentric rings of bone matrix surrounding the central canal

Where are lacunae located in an osteon?

Between adjacent lamellae

What are canaliculi?

Tiny channels connecting lacunae and the central canal for nutrient diffusion

Name the membrane that covers the outer surface of bone.

Periosteum

What structures secure tendons to the periosteum?

Sharpey's (perforating) fibers

Which canals run perpendicular to osteons allowing vessels to enter/exit bone?

Volkmann's (perforating) canals

What membrane lines the medullary cavity of long bones?

Endosteum

How many bones form the adult human skeleton?

206

How many bones compose the axial skeleton?

80

Which three major parts compose the axial skeleton?

Skull, vertebral column, and rib (thoracic) cage

What term denotes a rounded articular surface that fits into a fossa?

Condyle

Define foramen.

A hole in bone for passage of nerves or blood vessels

What projection is described as a sharp, slender process?

Spine

Which large, raised projection is unique to the femur?

Trochanter

What is a canal-like passageway in bone called?

Meatus

Which bone forms the only movable bone of the skull?

Mandible

Which cranial bone contains the sella turcica?

Sphenoid bone

What important structure passes through the foramen magnum?

Spinal cord

Which bone forms the forehead region?

Frontal bone

What are fontanels?

Membranous areas of an infant’s skull where bone has not yet formed

Approximately when do fontanels close?

Around 24 months of age

Name the four principal fontanels.

Anterior, posterior, anterolateral (sphenoid), posterolateral (mastoid)

Which bone in the neck does not articulate with any other bone?

Hyoid bone

Primary function of the hyoid bone?

Attachment site for tongue and neck muscles

Which suture lies between the two parietal bones?

Sagittal suture

The coronal suture separates which bones?

Frontal bone from the parietal bones

Name the depression on the temporal bone that receives the mandibular condyle.

Mandibular fossa

What are the superior and inferior nuchal lines?

Ridges on the occipital bone serving as muscle attachment sites

Cartilage is composed of cells called _ that reside in lacunae.

chondrocytes

Because cartilage is _ (lacking blood vessels), its regeneration is poor.

avascular

The type of cartilage depends on the kind and amount of _ in its matrix.

fibers

In _ cartilage the fibers are not visible microscopically.

hyaline

_ cartilage forms the embryonic skeleton and covers the ends of long bones.

Hyaline

Elastic cartilage contains many _ fibers, providing flexibility.

elastic

Elastic cartilage supports the external _ and the epiglottis.

ear

Fibrocartilage is characterized by thick _ fibers and few chondrocytes.

collagen

Intervertebral discs and the _ symphysis are composed of fibrocartilage.

pubic

Bone tissue contains cells called _ that occupy lacunae.

osteocytes

The functional unit of compact bone is the _ (Haversian system).

osteon

In an osteon, the central canal houses _ and nerves.

blood vessels

The concentric rings of bone matrix around the central canal are called _.

lamellae

Small channels that connect lacunae to each other and to the central canal are _.

canaliculi

The outer surface of every bone is covered by the _.

periosteum

Sharpey’s fibers are _ fibers that anchor tendons to the periosteum.

perforating

Perforating (_ ) canals allow blood vessels to enter and exit bone perpendicular to osteons.

Volkmann’s

The cavity within long bones that contains bone marrow is the _ cavity.

medullary

An adult human skeleton contains _ bones.

206

The axial skeleton contains _ bones.

80

Bones are connected to other bones by _

ligaments

Muscles attach to bones via connective tissue cords called _

tendons

A rounded articular surface that fits into a fossa is called a _.

condyle

A sharp, slender projection on a bone is termed a _.

spine

A canal-like passageway through bone is called a _.

meatus

The large opening at the base of the skull for the spinal cord is the _.

foramen magnum

The membrane-covered soft spots on an infant skull are called _.

fontanels

The _ bone, located below the mandible, does not articulate with any other bone.

hyoid

The anterior cranial fossa contains the crista galli and the _ plate of the ethmoid bone.

cribriform

The depression in the sphenoid bone that houses the pituitary gland is the _.

sella turcica

The middle cranial fossa includes openings such as the foramen ovale, spinosum, rotundum, and _.

lacerum

In the lateral skull view, the suture between parietal and occipital bones is the _ suture.

lambdoid

On the posterior skull, the bony prominence on the occipital bone is the external occipital _.

protuberance