Identification of Osteological Features of Fore Limb’s Bones of Animal (how to identify animal bones, anatomy of the body bones)
Hello and welcome. Hope you are doing well. If you want to learn about the osteological features of different bones of the animal body (anatomy of the body bones), you are in the right place.
Today, I will discuss identifying different osteological features of bones from the fore limb of an animal. Here, you will learn how to identify animal bones from the fore limb with pictures (pictures of animal bones). I
hope you have already completed the general terminology of anatomy. Okay, let’s start to learn and identify the animal bone anatomy (fore limb’s bones)
List of bones from the fore limb of an animal
We will learn and identify the osteological features of the following bones –
- Scapula bone
- Humerus bone
- Radius and ulna bones
- Carpal bones
- Metacarpal bones
- Phalanges (first, second and third phalanges)
Before starting, you should know what a skeleton is, what bone is, and the types of animal skeletons. Simply, I am trying to define those terms. Skeleton is the rigid (hard) framework of the body that supports the body’s internal structures, provides attachments to muscles, and helps with the body’s movement.
Again, bones are the main components of the skeleton.
In the anatomy of body bones of an animal, you will get two types of the skeleton (for learning purposes) –
Axial skeleton and
Appendicular skeleton
The axial skeleton includes the skull’s bone, vertebra bones (cervical vertebra, thoracic vertebrae, lumbar vertebra, sacrum, and coccygeal vertebra), rib, and sternum.
Whereas appendicular skeleton includes – bones of the fore limb (scapula bone, humerus, radius and ulna, carpal, metacarpal, and phalanges) and bones of the hind limb (hip bones, femur bone, tibia and fibula bones, tarsal, metatarsal and phalanges bones)
“Hope, I will discuss on types of animal skeletons in details later.”
Animal bone anatomy
Okay, now we will learn the osteological features of specific bones from the animal’s forelimbs. In each bone, we should complete the following points –
The shape of the bone with specialty
Location or direction
Surface, angle, and border
How to identify animal bone (right or left and handling of bones)
“Only important features are identified. If you want to learn more and an advanced level then you may go through books.”
Anatomy of a scapula bone
I hope you know that scapula is a flat triangular bone located at the cranio- lateral aspect of the thorax and directed downward and forward (for more, you need to follow class lectures or videos). We will identify the following osteological features from the anatomy of a scapula bone –
Two surfaces (lateral and medial)
Three angles (cranial, caudal, and distal or glenoid angle)
Three borders (anterior, posterior, and dorsal border)
Spine of scapula
Acromion process of scapular spine
Supraspinous fossa
Infraspinous fossa
Scapular cartilage
Supra glenoid tubercle or tuber scapulae
Coracoid process
Glenoid cavity
So, first, you should identify which surface faced laterally or which surface faced medially. On the lateral surface of the scapula, you will find the followings features –
Spine of scapula
Acromion process of scapular spine
Supraspinous fossa
Infraspinous fossa
The spine of the scapula has divided the scapula into two unequal halves – the above smaller part (especially in ruminant; differ in carnivores and others) is known as the supraspinous fossa, and the lower larger portion is known as the infraspinous fossa. So, you should identify the lateral surface of the scapula by the spine, then go for additional features.
On medial surface of scapula, you will find the followings features –
Subscapular fossa
It’s a very shallow area in the medial surface of the scapula
“So, if you able to identify the lateral or medial surface then you will able to identify other osteological features.”
At distal end of the scapula, you will find the followings features –
Glenoid cavity (shallow circular articular surface for the articulation of the head of humerus head and located at the distal end of the scapula)
Supra glenoid tubercle or tuber scapulae (located at cranial aspect of the glenoid cavity)
Coracoid process (located at medial to tuber scapulae)
Anatomy of humerus
It is a long twisted bone that is directed downward and backward. We will identify the following osteological features from the anatomy of the humerus of animals –
Head and neck of humerus
Four surfaces (anterior, posterior, lateral, and medial)
Two ends or extremities (proximal and distal)
The musculospiral groove of the humerus
Crest of humerus
Condyle and epicondyle of humerus
Olecranon fossa
Radial fossa
Lateral tuberosity
Medial tuberosity
Bicipital groove
Deltoid tuberosity
Teres tubercle
Supratrochlear foramen (in dog humerus)
But, first, you should identify which extremity faced proximally or distally and which surface faced laterally or medially. For that, you should find a large, circular convex structure that articulates with the glenoid cavity of the scapula (called the head). The head is faced medially and located at the proximal extremity of the humerus.
Again, you should find a smooth spiral structure at the humerus’s lateral surface (called the humerus’s musculospiral groove of the humerus. You may consider those structures to identify the other structures. (Head medially and musculospiral groove laterally; now, you will also be able to identify the right and left humerus)
In the proximal extremity, you will find the following structures-
Head (expand circular area) and neck (constricted area under the head)
Lateral tuberosity- larger and prominent (at the lateral surface) and medial tuberosity (at the medial surface of the humerus)
Bicipital groove (divided lateral tuberosity into two portions)
In the distal extremity, you will find the followings structures –
Lateral condyle (faced laterally; having a small epicondyle laterally) and medial condyle (faced medially)
Radial fossa (cranially)
Olecranon fossa (faced caudally at distal end)
Other important structures in body of humerus bone –
Musculospiral groove (faced laterally)
Crest of the humerus (faced anterior and lateral surface)
Deltoid tuberosity (located in middle of the humeral crest)
Anatomy of radius and ulna bone
They are fused with the long bone and directed vertically. The radius bone is larger, and the ulna is an ill-developed long bone that fused with the radius at its postero-lateral aspect. We will identify the following osteological features from anatomy of radius and ulna bones of animals –
Radial tuberosity
Articular surface in distal extremity of radius for carpal bones (proximal carpal bones)
Proximal interosseous space and distal interosseous space (between radius and ulna
Caudomedial protuberance of radius
Coronoid process of the radius
Olecranon process of ulna
Anconneous process of ulna
Styloid process of ulna
Okay, first, you should identify the radius and ulna bone and proximal or distal extremities, and right or left radius ulna bones. For that –
You should find ulna bone; it is thinner, longer than the radius, and faces the postero-lateral aspect of the radius bone. As ulna bone is faced laterally, now you will be able to identify an animal’s right or left radius and ulna bone.
For confirmation, you need to identify the caudomedial protuberance of radial bone at its caudomedial aspect. So, this structure will be faced medially.
To identify the proximal and distal extremities, you should find an expanded portion (olecranon process) and a semilunar notch (anconeus process) from the ulna bone. They are located proximal extremity of the bone.
Other structures from radius and ulna bone
Radial tuberosity (at the anterior surface; proximal part; middle)
Anconeus process in the ulna and articular surface in radius (articulates with olecranon fossa of humerus; located at the proximal extremity of the bone)
Articular surface in the distal extremity of radius bone (articulates with proximal row of carpal bones)
Styloid process of the ulna (pointed projection of ulna at the distal end, faced laterally)
Anatomy of carpal bones
In animals, there are two rows of carpal bones – proximal and distal (total of six in number). A proximal row consists – of radial carpal, intermediate carpal, ulnar carpal, and accessory carpal bone. (Accessory carpal bone faced laterally; So, now you may identify the proximal carpal bone from lateral to medial in this way – accessory, ulnar, intermediate, and radial; in case of a ruminant). The distal row consists of – the second and third fused (faced medially) and fourth carpal (faced laterally).
Anatomy of metacarpal bones
Metacarpal bones are of two types – large metacarpal and small metacarpal bones. In ruminant, you will find two numbers of the large metacarpal bone and one small metacarpal bone. In the case of a horse, you will find a single metacarpal bone and two small metacarpal bones. In the case of a dog, you will find five numbers of metacarpal bones.
Here, we will identify the followings structures or features from metacarpal bones –
Small metacarpal – faced at the postero-lateral surface (fifth)
Large metacarpal bones (third and fourth fused metacarpal)
Metacarpal tuberosity
Facet for carpal bones at the proximal extremity
Facet for sesamoid bones at the posterior portion of metacarpal (at distal extremity)
Longitudinal groove at the dorsal surface of metacarpal
Lateral and medial condyle at the distal extremity of metacarpal
Intercondyloid cleft at the distal extremity
Okay, first, you need to confirm which portion is faced laterally or medially (that will help you to identify the animal’s right or left metacarpal bone). For that –
You should find the larger facet for carpal bones (distal row carpal bones) in the proximal extremity of the metacarpal bone. This larger facet for distal row carpal faced medially. Now, you will be able to identify the medial and lateral surface of a bone. Now, you will also be able to identify the right and left metacarpal bones.
To identify the proximal and distal end, you need to find a condyle divided by a cleft (intercondyloid cleft). They are placed at the distal ends of the metacarpal bone.
To identify the dorsal surface, you need to find a longitudinal groove.
The metacarpal bone is called cannon bone. Small metacarpal (second and fourth metacarpal) are called splint bones in the horse.
Sesamoid bones in the fore limb of an animal
Some small seed-like, elongated oval bones are divided into – proximal sesamoid and distal sesamoid bones.
There are four sesamoid bones (two for each digit, in the case of a ruminant) at the posterior aspect of the metacarpal at its distal end. Those sesamoid bones are called proximal sesamoid bones.
In distal sesamoid (navicular bone), you will find two (one for each digit; in the case of a ruminant) in the posterior portion between the second and third phalanges.
Anatomy of phalanges
You know, there are two digits in ruminant. You will find three phalanges in each digit – first, second and third.
We need to identify the following structure from the first phalanges –
The proximal concave articular surface
Articular facets for sesamoid bones at the posterior aspect of the first phalanges
Larger lateral condyle
Others
Second phalanges (consists of three surfaces)
Third phalanges (consists of four surfaces and are hoof-shaped)
Conclusion
I hope you have an idea of the osteological features of different bones of the animal body (anatomy of the body bones). Here, you will learn how to identify animal bones from the fore limb with pictures (pictures of animal bones).
I hope you have already completed the general terminology of anatomy. You may also learn the basic anatomy of the organs from the DIFFERENT SYSTEM OF ANIMAL BODY.
If you want to know more about the anatomy of animal body bones, you should follow class lectures or go through the BOOKS.
If possible, I will update or enrich the information on this topic in the future.
If there is any mistake in the above information or if you have any suggestions for me, please, let me know in the comment box. Thank you so much.