Module 3 - BONES

Made of some variety of cartilage tissue molded to fit its body location and function.

A layer of dense irregular connective tissue surrounding the cartilage. Acts a girdle to resist outward expansion when the cartilage is compressed.

Looks similar to frosted glass when freshly exposed, provides support with flexibility and resilience. The most abundant skeletal cartilages.

• Articular cartilages, which cover the ends of most bones at movable joints.
• Costal cartilages, which connect the ribs sternum.
• Respiratory cartilages, which form the skeleton of the larynx and reinforce other respiratory passageways.
• Nasal cartilages, which support the external nose.

Cartilage with abundant elastic fibers; more flexible than hyaline cartilage.

The most compressible type of cartilage; resistant to stretch. Forms vertebral discs and knee joint cartilages.

Growth accomplished by the addition of new layers onto those previously formed.

Lacunae-bound chondrocytes divide and secrete new matrix, expanding the cartilage from within.

Forms the long axis of the body and includes the bones of the skull, vertebral column, and rib cage. These bones protect, support, or carry other body parts.

Consists of the bones of the upper and lower limbs and the girdles (shoulder bones and hip bones) that attach the limbs to the axial skeleton.

the shaft of the bone; contains mostly compact bone

the ends of the long bone; contains mostly spongy bone covered on the outside by compact bone.

remnant of epiphyseal plate (hyaline cartilage) where growth took place.

Lines the shaft; contains osteoclasts (cells which break down bone) and osteoblasts (cells which manufacture bone matrix)

Covers outside of bone; Sharpey’s fibers anchor it to the bone and Volkmann Canals provide a passageway for blood vessels originating in the periosteum to enter the bone

A layer of hyaline cartilage which cushions the ends of articulating bones

Contains yellow bone marrow (mostly fat) in the adult and red bone marrow (which makes blood cells) in infants.

Large rounded projection

narrow, prominent ridge of bone

large, blunt, irregular surface - only found on femur

narrow ridge of bone

small rounded projection

raised area above a condyle

sharp, slender projection

any bony prominence

bony expansion carried on a narrow neck

smooth, nearly flat articular surface

rounded articular projection

arm like bar of bone

canal-like passageway

cavity within a bone, mucosae lined

a shallow, basin like depression

is a furrow

narrow, slit like opening

round or oval opening through a bone

large roughly circular system which consist of concentric layers of bone matrix called lamellae

the holes inside the matrix of bone where osteocytes are found

Mature bone cells

canals through which nourishment travels and waste is removed for the osteocytes, as well as connecting the osteocytes with haversian canal system vessels.

areas between Haversian systems

The frontal bone forms the anterior part of the cranium and the anterior cranial floor.  On the upper margin of each orbit we see supraorbital foramina through which blood vessels and nerves pass to the forehead tissues. 

• Paired parietal bones form most of the cranial vault.  Here we see four major sutures:
• 1. Coronal Suture
• 2. Sagittal Suture
• 3. Lambdoidal Suture
• 4. Squamous Suture

is found where the parietal and frontal bones meet

is located at the midline where the two parietals meet. 

found where parietal and occipital bones meet posteriorly

located where the parietal and temporal bones meet on the side

The occipital bone joins with the sphenoid in the cranial floor forming most of the back and base of the skull.  In the base we see the foramen magnum.  This  serves as a passage between the vertebral and cranial cavities allowing the medulla oblongata to connect with the spinal column.  On each side of the foramen magnum are occipital condyles which articulate with the axis allowing nodding of the head.

The squamous region has a zygomatic  process which meets the zygomatic bone of the face.  The mandibular fossa on the inferior surface of the zygomatic process receives the mandibular condyle forming     the temperomandibular joint

The tympanic region surrounds the   external auditory meatus.  Beneath this is the styloid process where muscles and ligaments attach.   These structures hold the hyoid bone in place. 

The mastoid process found here is a point   where some of the neck muscles are anchored.  It  contains   the   mastoid sinuses

The petrous region forms part of the middle     cranial fossa which supports the temporal lobes of the brain.

The sphenoid bones extends across the cranial floor and articulates with all of the cranial bones.  The optic foramina allow passage of the optic nerves and ophthalmic arteries.  The sella turcica is a depression supporting the pituitary gland

The ethmoid bone forms most of the bony area between the nasal cavity and the orbit.  The crista galli helps to secure the brain in the cranial cavity.  The cribriform plates have tiny holes allowing the olfactory nerves to pass through to join the olfactory bulbs.  A perpendicular plate goes downward forming the superior part of the nasal septum

The facial skeleton is made up of fourteen bones.  Thirteen unmovable and a movable jawbone.  Only the mandible and vomer are unpaired

The mandible forms the lower jaw.  The body forms the chin and the rami are the upright portions.  The mandibular condyle articulates with the mandibular fossa of the temporal bone forming the temporomandibular joint.

The maxillary bones  form the upper and carry the upper teach.  The palatine processes project posteriorly and form the anterior part of the hard palate

The zygomatic bones form the prominence of the cheek bones and the lateral walls and floor of the orbit.  Each has a process that extends posteriorly to join the zygomatic process of the temporal bone.  Together these bones form the zygomatic arch. 

The nasal bones are thin, rectangular bones which fuse to form the bridge of the nose.  

The lacrimal bones are small bones located in the medial wall of each orbit.  The lacrimal sulcus drains tears from the eye to the nasal cavity.

The palatine bones form the posterior portion of the hard palate and the floor of the nasal cavity. 

The vomer bone joins with the perpendicular plate of the ethmoid bone forming part of the nasal septum

These bones form part of the lateral walls of the nasal

The vertebral column provides axial support and protects the extremely delicate spinal cord.  It consists of vertebrae and a fused sacrum.  The vertebrae have different structures in different parts of the spinal cord and include: 7 cervical;   12 thoracic; 5 lumbar and a sacrum (fused).  The vertebrae separated by intervertebral discs of fibrocartilage.

All vertebrae have certain common features.  They have a rounded body or centrum with two vertebral arches extending from it.  The vertebral arches are composed of a lower portion or pedicle and an upper portion or lamina. The two sides meet in a spinous process. The transverse processes project laterally from the vertebral arch and superior and inferior articular processes allow articulation with adjacent vertebrae.

The atlas does not have a body and has superior articular facets the hold the occipital condyles of the skull.  This arrangement makes it possible to nod your head

The second cervical vertebra, the axis, has a pivot called an odontoid process which allows you to rotate your head as in nodding no. 

• •Spinous process bifurcated (split)
• •Transverse process contains transverse foramina
• •Body oval

• •Long sharp process
• •Body heart shaped
• •Foramen circular

Lumbar Vertebrae bear much of the stress of the vertebral column and are therefore massive.  The spinous process is hatched shaped

Five sacral vertebrae fuse to form the sacrum.  Two alae form the sacroiliac joints of the pelvis.  The coccyx is the last portion of the vertebral column.  It is formed from fusion of three to five vertebrae. (See Figure).

The bony thorax consists of the sternum and costal cartilages anteriorly (secure the ribs to the sternum), ribs and thoracic vertebrae dorsally. 

formed by fusion of 3 bones: the manubrium; body, and xiphoid process. The manubrium articulates with the clavicles and ribs articulate with the manubrium and body of the sternum. 

consists of the bones of the pectoral girdle which attaches the upper limbs to the body trunk, the arms pelvic girdle which secures the lower limbs and the legs.

The humerus is the sole bone in the upper arm .  Its head fits into the glenoid fossa of the scapula. 

Two bones, the radius and ulna make up the forearm.  These bones articulate with each other at the radioulnar joint and are connected by an interosseous membrane.  The ulna is a bit longer and is mostly responsible for forming the ulnar joint.  At the proximal end of the ulna, we see the olecranon and coronoid process which are separated by the semilunar notch.  This grips the trochlea forming a hinge joint allowing the arm to be bent.

Each hand is made up of a wrist, a palm and five fingers.  In the wrist are eight carpal bones bound together by ligaments.  The palm has five metacarpal bones forming the knuckles when you make a fist.  The fingers contain three phlanges which the thumb has two

The pelvic girdle is made up of two  os coxae and the sacrum and coccyx. 

Each os coxa has three parts:  the ilium, ischium and pubis. 

The lower limb includes the femur or thigh bone, the tibia and fibula of the lower leg, and the bones of the foot. 

Longest Strongest bone

The tibia has medial and lateral condyles articulating with the femur, the tibial tuberosity which is the point where the patellar (kneecap) ligaments attach and the medial malleolus which is the bulge of the inner ankle. The fibula is thinner and has a lateral malleolus forming the outer part of the ankle.

Each foot consists of an ankle, an instep and 5 toes.  In the ankle the calcaneus and talus bear most of the weight of the body.  The instep consists of 5 metatarsal bones and the toes contain phlanges.

There are 275 bones in a fetus and 206 in an adult.  The discrepancy is due to fusion of bones as in the os coxa.  Fontanels  are indentations between the fetal skull bones.  These are  fibrous membranes which allow for compression during birth and for growth during fetal life.  These membranes will ossify by approximately 22 months.

• 1. Sutures – Irregular edges of bone interlock and are bound by very short connective tissue fibers.
• 2. Syndesmoses – Bones are connected by short connective tissue fibers but do not interlock.
• 3. Gompohses – Teeth are secured in a bony sock by very short periodontal ligament.

Cartilaginous joints have bones joined by a plate of cartilage.  They lack a joint cavity. 

•Synchondroses – Bony parts are united by hyaline cartilage.

•Symphyses- Bones connect by flat plate of hyaline cartilage.

Synovial joints are joined by a fluid containing joint cavity. 

• Articular capsule – Creates joint cavity.  It consists of two layers synovial membrane and a fibrous capsule of dense irregular connective tissue.
• Synovial membrane – Lines inner surface of joint cavity and secretes synovial fluid which reduces friction. 
• Articular cartilage – Hyaline cartilage covers the surfaces of the articulating bones.
• Articular capsule – This is reinforced with ligaments

The  knee joint is the point where the tibia and femur articulate.  This complex structure is the largest joint in the body.  This hinge diarthrosis permits flexion, extension and some rolling and gliding movements.

•   Anteriorly it is stabilized and protected by the patella and patellar ligament which form the gliding patellofemoral joint.  The insertion of the quadriceps femoris muscle forms two supportive bands called the lateral and medial patellar retinacula.  In order to decrease friction, the knee joint has four bursae on its anterior aspect:
• 1.Superficial infrapatellar
• 2.Suprapatellar
• 3.Prepatellar
• 4.Deep infrapatellar

On the posterior aspect, we find two superficial ligaments:  the oblique popliteal and the arcuate popliteal ligament.  The anterior and posterior cruciate ligaments are located deep in the joint.  Also on the back we find the popliteal and semimembranosus bursae.    The medial and lateral sides of the knee joint are supported by 2 collateral ligaments: the fibular collateral ligament and the tibial collateral ligament.    Lateral and medial menisci are found in the knee joint between the distal femoral and proximal tibial condyles/  these are connected by a transverse ligament.  The knee joint works well during walking and running and in supporting the body.  It can take moderate stress such as that seen in athletics without damage.  Knee injuries often require surgery and heal with difficulty since cartilage is avascular.