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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

demand and supply rules
jamac Reply
compative demand and supply
jamac
compare demand and supply
jamac
what are simple epithelial tissues
Ushie Reply
is a type of tissue which covers the external and internal part of the body
Fatou
more information would be better understanding.
Tasha
what is platelets
Lilian Reply
platelet is also known as thrombocyte.thrombo means clot.it is a formed element of blood formed from fragment of megakaryocyte surrounded by plasma membrane in the redbone marow
Adeyemo
what is diabetes insipidus
namrata Reply
it is an infection due to less or no secretion of ADH characterized by excretion of dilute urine
Meshack
Infection? I don't think any form of diabetes, whether it's mellitus or insipidus, is caused by an infection.
Matias
ya
Akanyijuka
it is the disorder of salt & water metabolism
Emma
diabetes inspidus is a condition were the liver can't produce insulin to convert the excess sugar to glycogen.
mangs
sorry that is for diabetes mellitus
mangs
what is septal cartilage
Arthur Reply
I don't understand please
Esther Reply
hey
Austine
good evening boss
Austine
Evening
Esther
good evening
Melissa
evening
Vitus
hi
Rodgers
good morning
Aurelia
hello
Helsa
you guys are from ?
Aurelia
Philippines
Helsa
im from india
Aurelia
Hello
Amos
why
Sami
wat
Rodgers
what's that
Gift
what's the medulla?
alhussiney Reply
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum
Ludmila
define bone in simple terms
Mhoses Reply
bones are made up by collagen and calcium phosphate
Aurelia
yes
Confidence
Bones are the hard large calcareous connective tissue of which the adult skeleton of most vertebrates is chiefly composed
Olalekan
Bone is the substance that forms skeleton
Frances
good morning
Mrinal
Skelton muscles is any disorder of calcium
Mrinal
Bones protect the various organs of the body
Celina
Bone is a hard strong and durable type of connective tissue
Bkv
bone is a hard, calcareous connective tissue which gives structural support to the body and helpless in its locomotion!
Divya
It also is the main site for synthesis of the RBCs
Divya
thanks for your answers
Mhoses
A diagram of epithelial tissue
Emmanuel Reply
What does the urinary regulate blood pressure
Jennifer Reply
functions of melatonin
marion Reply
d. inversely proportional
John Reply
Airway resistance in the human lung is? a. Greatest in the generation of distal bronchioles in healthy people because these airways have the smallest radii b. Not increased during a forced expiration in a healthy subject c. Decreased when breathing through the mouth d. Inversely proportional
Maryam Reply
1. Chemical level 2. Cellular level 3.Tissue level 4. Organ level 5.Organ system level 5.Organismal level
Jamela Reply
d
HMD
High
HMD
hlw
Maryam
------is not a content of femoral canal? a. Fatty tissue b. Femoral nerve c. Lymph vessels d. Lymph node
Maryam
a
Alhassan
why there is bleeding in menstruation?
KUHELI Reply
menopause
Vasu
no
KUHELI
no one ready to help me
Maryam
skin
The following hormones increase the blood glucose level except_____________? a. Parathormone b. Growth Hormone c. Epinephrine d. Thyroxine
Maryam
c.epinephrine
Divya
Which of the following is NOT a characteristic feature of alveoli in the lung? a. Poor blood supply b. A large surface area c. Thin walls d. Chemical layer called surfactant
Maryam
a.poor blood supply
Divya
poor blood supply
Tanvi
Excess of cortisol causes______________? a. Acromegaly b. Conn’s syndrome c. Diabetes insipidus d. Cushing syndrome
Maryam
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Maryam
cushing syndrome
Tanvi
thank you
Maryam
Airway resistance in the human lung is? a. Greatest in the generation of distal bronchioles in healthy people because these airways have the smallest radii b. Not increased during a forced expiration in a healthy subject c. Decreased when breathing through the mouth d. Inversely proportional
Maryam
what happens to the brain when one cannot sleep
aghedo
it means melatonin is not released enough to make u fall asleep or there is a disturbance or destruction for melatonin to be released on time
Mhoses

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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