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Bone markings

The surface features of bones vary considerably, depending on the function and location in the body. [link] describes the bone markings, which are illustrated in ( [link] ). There are three general classes of bone markings: (1) articulations, (2) projections, and (3) holes. As the name implies, an articulation    is where two bone surfaces come together (articulus = “joint”). These surfaces tend to conform to one another, such as one being rounded and the other cupped, to facilitate the function of the articulation. A projection    is an area of a bone that projects above the surface of the bone. These are the attachment points for tendons and ligaments. In general, their size and shape is an indication of the forces exerted through the attachment to the bone. A hole    is an opening or groove in the bone that allows blood vessels and nerves to enter the bone. As with the other markings, their size and shape reflect the size of the vessels and nerves that penetrate the bone at these points.

Bone Markings
Marking Description Example
Articulations Where two bones meet Knee joint
Head Prominent rounded surface Head of femur
Facet Flat surface Vertebrae
Condyle Rounded surface Occipital condyles
Projections Raised markings Spinous process of the vertebrae
Protuberance Protruding Chin
Process Prominence feature Transverse process of vertebra
Spine Sharp process Ischial spine
Tubercle Small, rounded process Tubercle of humerus
Tuberosity Rough surface Deltoid tuberosity
Line Slight, elongated ridge Temporal lines of the parietal bones
Crest Ridge Iliac crest
Holes Holes and depressions Foramen (holes through which blood vessels can pass through)
Fossa Elongated basin Mandibular fossa
Fovea Small pit Fovea capitis on the head of the femur
Sulcus Groove Sigmoid sulcus of the temporal bones
Canal Passage in bone Auditory canal
Fissure Slit through bone Auricular fissure
Foramen Hole through bone Foramen magnum in the occipital bone
Meatus Opening into canal External auditory meatus
Sinus Air-filled space in bone Nasal sinus

Bone features

This illustration contains three diagrams. The left diagram is titled examples of processes formed where tendons or ligaments attach. The image shows an anterior view of the femur and an anterior view of the humerus. For the femur, the distal epiphysis contains a smaller lateral bulge and a larger medial bulge. These are examples of condyles. The inner halves of the two condyles as well as the groove between them compose a facet. An oval-shaped ridge on the medial surface of the distal metaphysis is an example of a tubercle. On the proximal epiphysis of the femur, the large knob that attaches to the hip socket is an example of a head. The tip of the head contains a small depression, an example of a fovea called the fovea capitis. On the humerus, the distal epiphysis contains a central depression that is an example of a fossa. Two condyles are located on the right and left sides of the fossa. The diaphysis of the humerus contains a small ridge running up the shaft that is an example of a tuberosity. The proximal epiphysis of the humerus contains a lateral and a medial bulge that are both examples of tubercles. Finally, a narrow groove runs from the center of the proximal metaphysis in between the medial and lateral condyles. This is an example of a sulcus. The middle image is entitled elevations or depressions. It shows an anterior view of the hip bones. The hip bones are shaped like two wings that join at the bottom. The crest along the upper edge of each hip bones, at the tip of each “wing” is an example of an elevation. A depression on the inner surface of both hip bones just under the crest is called out as a fossa. The right image is entitled examples of openings and shows an anterior view of the skull. The bone underlying the chin is an example of a protuberance while two small holes above each eye socket are examples of foramen. Five green sinuses surround the nose cavity are colored green. These are sinuses because they are hollowed out cavities within the skull bones. A small channel leads into the corner of each eye where the tear ducts occur. These two channels are both examples of a canal. Finally, the bones that form the posterior wall of the eye socket have a small crack running diagonally away from the nose. These are examples of fissures.
The surface features of bones depend on their function, location, attachment of ligaments and tendons, or the penetration of blood vessels and nerves.

Bone cells and tissue

Bone contains a relatively small number of cells entrenched in a matrix of collagen fibers that provide a surface for inorganic salt crystals to adhere. These salt crystals form when calcium phosphate and calcium carbonate combine to create hydroxyapatite, which incorporates other inorganic salts like magnesium hydroxide, fluoride, and sulfate as it crystallizes, or calcifies, on the collagen fibers. The hydroxyapatite crystals give bones their hardness and strength, while the collagen fibers give them flexibility so that they are not brittle.

Although bone cells compose a small amount of the bone volume, they are crucial to the function of bones. Four types of cells are found within bone tissue: osteoblasts, osteocytes, osteogenic cells, and osteoclasts ( [link] ).

Bone cells

The top of this diagram shows the cross section of a generic bone with three zoom in boxes. The first box is on the periosteum. The second box is on the middle of the compact bone layer. The third box is on the inner edge of the compact bone where it transitions into the spongy bone. The callout in the periosteum points to two images. In the first image, four osteoblast cells are sitting end to end on the periosteum. The osteoblasts are roughly square shaped, except for one of the cells which is developing small, finger like projections. The caption says, “Osteoblasts form the matrix of the bone.” The second image called out from the periosteum shows a large, amorphous osteogenic cell sitting on the periosteum. The osteogenic cell is surrounded on both sides by a row of much smaller osteoblasts. The cell is shaped like a mushroom cap and also has finger like projections. The cell is a stem cell that develops into other bone cells. The box in the middle of the compact bone layer is pointing to an osteocyte. The osteocyte is a thin cell, roughly diamond shaped, with many branching, finger-like projections. The osteoctyes maintain bone tissue. The box at the inner edge of the compact bone is pointing to an osteoclast. The osteoclast is a large, round cell with multiple nuclei. It also has rows of fine finger like projections on its lower surface where it is sitting on the compact bone. The osteoclast reabsorbs bone.
Four types of cells are found within bone tissue. Osteogenic cells are undifferentiated and develop into osteoblasts. When osteoblasts get trapped within the calcified matrix, their structure and function changes, and they become osteocytes. Osteoclasts develop from monocytes and macrophages and differ in appearance from other bone cells.

Questions & Answers

what are diseases in the bood
Azoyenime Reply
right hypochondriac rision how meain word
Ganesh Reply
Diabetes insipidus or diabetes mellitus would most likely be indicated by ________.
oral cavity how miean
Ganesh Reply
oral cavity how mean what
seems to me every one is here a doctor and worse part is that even they donot know what to ask.
they know what to ask the problem is how to ask it.too much broken english.
dear George ongeche I think if they ask these kind questions and telling themselves as HCPs or medical student's .these are the basic ones go ask something more interesting .
what is blood red
Ahmad Reply
what is human anatomy?
Arpita Reply
tell me what is human anatomy?
what is Openstax?
arpita jana I think it's not the forum to ask such basic question...
study of structure of an object in this case human body.
what are deferent between trasemicacid and vitamin k
Ubah Reply
This medication is used to treat heavy bleeding during your menstrual period. Tranexamic acid works by slowing the breakdown of blood clots, which helps to prevent prolonged bleeding. It belongs to a class of drugs known as antifibrinolytics
In the body, vitamin K plays a major role in blood clotting. So it is used to reverse the effects of “blood thinning” medications when too much is given; to prevent clotting problems in newborns who don’t have enough vitamin K; and to treat bleeding caused by medications including salicylates, sulfo
Vitamin K plays a key role in helping the blood clot, preventing excessive bleeding. Unlike many other vitamins, vitamin K is not typically used as a dietary supplement. Vitamin K is actually a group of compounds. The most important of these compounds appears to be vitamin K1 and vitamin K2. Vitami
how much tha total vertebrea bone
26 vertebrea bone
wathe is blood function
dhena Reply
Blood, fluid that transports oxygen and nutrients to the cells and carries away carbon dioxide and other waste products. ... It is a tissue because it is a collection of similar specialized cells that serve particular functions. These cells are suspended in a liquid matrix (plasma), which makes the 
how tissue carries waste matrial
how many bone in human body?
Islam Reply
what is endocrin? plese help many people.
heart layers
endoceime is the inner layer of heart
What is buffer?
Peer Reply
a buffer is a solution that resists a chemical change.
Yup it also balances the solutions
most common side effect reported by users emergency contraceptive pill
Shivvir Reply
spotting .breakbrough bleeding .weightgain.breast tenderness.mood alteration. headache
How many systems are in the body?
Irvin Reply
names the systems pls
name the systems pls
integumentary system, lymphatic system, skeletal system, digestive system, cardiovascular system, reproductive system, respiratory system, urinary system, endocrine system
approximately 11 system
what's the meaning of Acidphosphacidic
Tiwa Reply
most common source of phosphoric acid is an 85% aqueous solution; such solutions are colourless, odourless, and non-volatile. The 85% solution is a syrupy liquid, but still pourable. Although phosphoric aciddoes not meet the strict definition of a strongacid, the 85% solution is acidic 
What is osteoblast and what is osteoclast?
osteoblast is the bone forming cells osteoclast is the bone dissolving cells
Which of the following is most likely to be found evenly distributed in water in a homogeneous solution? a. sodium ions and chloride ions b. NaCl molecules c. salt crystals d. red blood cells
Ashley Reply
what are the bases of classifying epithelium
Boahen Reply
What iz anti-cubical-fosa?
Peer Reply
Deep portion above the brachial artery Where we put stathescope while checking blood pressure

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