Humerus bone osteology Animation : Bony mandmarks, Development and Clinical anatomy π¦΄π¦΄π¦΄
Summary
TLDRThe video script offers an in-depth look at the anatomy of the humerus, the largest long bone in the upper limb. It details its structure from the head to the lower end, highlighting key features such as the anatomical and surgical neck, greater and lesser tubercles, intertubercular sulcus, and the shaft's borders and surfaces. The script also discusses ossification centers, clinical correlations including nerve associations and common fracture sites, and touches on shoulder joint dislocation, particularly the inferior type.
Takeaways
- π The humerus is the largest and longest bone in the upper limb, with its upper end comprising the head, neck, greater and lesser tubercles, and the intertubercular sulcus.
- πΊ The head of the humerus is smooth,ηε½’ (spherical) in shape, and covered with articular cartilage, articulating with the glenoid cavity of the scapula to form the shoulder joint.
- π‘ The anatomical and surgical necks of the humerus are important for understanding the bone's structure and potential sites of injury or fractures.
- π₯ The surgical neck is a common site for fractures due to its location at the junction between the upper end and the shaft of the humerus.
- πͺ The greater and lesser tubercles are prominent features of the humerus, contributing to the shoulder's shape and providing attachment points for various ligaments and muscles.
- ποΈββοΈ The intertubercular sulcus, also known as the bicipital groove, houses the long head of the biceps brachii and the ascending branch of the anterior circumflex humeral artery.
- π The shaft of the humerus is cylindrical above and triangular below, with three borders and three surfaces that are significant for muscle attachment and bone structure.
- π The lower end of the humerus is broad and has both an articular part (capitulum) and a non-articular part, with the radial fossa being a notable feature.
- 𦴠The determination of the side of the humerus can be made by observing the position of the head, lesser tubercle, intertubercular sulcus, and medial epicondyle.
- 𧬠The humerus develops from multiple ossification centers, with the upper end fusing by age seven and the lower end by age 14, while the full fusion with the shaft occurs in early adulthood.
- π Common fractures of the humerus include the surgical neck, shaft, and supracondylar region, which can result in injury to nerves and blood vessels in the area.
Q & A
What is the humerus and where is it located?
-The humerus is the largest and strongest long bone in the upper limb, located in the arm.
Describe the upper end of the humerus.
-The upper end of the humerus consists of the head, neck, greater and lesser tubercles, and the intertubercular sulcus. The head is smooth, medially backwards and upwards directed, and articulates with the glenoid cavity of the scapula to form the shoulder joint.
What are the two necks of the humerus and their functions?
-The anatomical neck is the constricted portion surrounding the head and gives attachment to the shoulder joint capsule, except medially. The surgical neck is the junction between the upper end and the shaft and is a common site for fractures.
What is the significance of the greater and lesser tubercles on the humerus?
-The greater tubercle forms the prominence of the shoulder and has the lateral margin that gives attachment to the transverse ligament. The lesser tubercle is smaller, located in the anterior aspect of the upper end, and its lateral margin also gives attachment to the transverse ligament.
What does the intertubercular sulcus contain?
-The intertubercular sulcus, also known as the bicipital groove, contains the long head of the biceps brachii and the ascending branch of the anterior circumflex humeral artery.
Describe the shaft of the humerus and its features.
-The shaft of the humerus is cylindrical above and flat, triangular below, consisting of three borders (anterior, lateral, and medial) and three surfaces (anteromedial, anterolateral, and posterior). The anterior border extends from the lower end of the greater tubercle to above the radial fossa, while the medial border extends from the lesser tubercle to the medial epicondylar sulcus.
What are the two fossae located at the lower end of the humerus and their functions?
-The radial fossa is a hollow depression on the posterior surface of the lower end, lodging the radial head of the radius during elbow extension. The coronoid fossa is a small depression situated just above the trochlea, lodging the anterior margin of the coronoid process of the ulna during elbow flexion.
How many centers of ossification are involved in the development of the humerus and when do they typically appear?
-There is one primary center for the shaft, three secondary centers for the upper end, and four secondary centers for the lower end of the humerus. The upper end centers appear in the first year for the head, third year for the greater tubercle, and fifth year for the lesser tubercle. The lower end centers appear in the second year for the capitulum and lateral lip of the trochlea, in the 10th year for the medial part of the trochlea, and in the 16th year for the lateral epicondyle.
What are the clinical implications of humerus fractures and common sites?
-Common sites for humerus fractures include the surgical neck, shaft, and the supracondylar region. These fractures can injure nerves such as the auxiliary nerve around the surgical neck, radial nerve in the radial groove, and the ulnar nerve behind the medial epicondyle. Supracondylar fractures often occur in young individuals due to falls on outstretched hands.
What is the most common dislocation involving the humerus and why does it occur?
-The most common dislocation involving the humerus is the inferior dislocation of the shoulder joint. This occurs more frequently due to the loose nature of the capsule and the large size of the head compared to the glenoid cavity.
Outlines
𦴠Anatomy of the Humerus
This paragraph delves into the detailed anatomy of the humerus, the largest and strongest long bone in the upper limb. It describes the upper end of the humerus, which includes the head, neck, greater and lesser tubal, and the intertubercular sulcus. The head's articulation with the glenoid cavity of the scapula forms the shoulder joint. The paragraph also explains the anatomical and surgical necks, the greater and lesser tubercles, and the intertubercular sulcus, which contains the long head of the biceps brachii and the ascending branch of the anterior circumflex humeral artery. The shaft of the humerus is cylindrical above and triangular below, with three borders and surfaces. The lower end of the humerus is broad, with an articular and non-articular part, and the paragraph concludes with the clinical correlation of nerves related to the humerus and common sites for fractures.
πͺ Development and Fractures of the Humerus
The second paragraph focuses on the development of the humerus, detailing the primary and secondary ossification centers for the upper and lower ends. It outlines the timeline for the appearance of these centers, from the first year of life to the 14th year. The paragraph also discusses the fusion of these centers with the shaft, which occurs by the 20th year for the upper end and between 16 to 17 years for the lower end, with the medial epicondyle fusing by 18 years. Additionally, it touches on the clinical aspects of the humerus, including the nerves related to it, such as the auxiliary nerve around the surgical neck, the radial nerve in the radial groove, and the ulnar nerve behind the medial epicondyle. The paragraph concludes with a discussion on common sites for fractures of the humerus and the potential injuries to the median nerve and brachial artery that can result from such fractures.
Mindmap
Keywords
π‘Humerus
π‘Anatomical Neck
π‘Surgical Neck
π‘Greater Tubercle
π‘Lesser Tubercle
π‘Intertubercular Sulcus
π‘Shaft of Humerus
π‘Radial Groove
π‘Epicondyles
π‘Capitulum
π‘Ossification Centers
π‘Fracture
Highlights
The humerus is the largest and strongest long bone in the upper limb.
The upper end of the humerus consists of the head, neck, greater and lesser tubercles, and the intertubercular sulcus.
The head of the humerus articulates with the glenoid cavity of the scapula to form the shoulder joint.
There are two types of necks in the humerus: the anatomical neck and the surgical neck.
The greater tubercle forms the prominence of the shoulder.
The lesser tubercle is located in the anterior aspect of the upper end, just above the surgical neck.
The intertubercular sulcus, also known as the bicipital groove, contains the long head of the biceps brachii and the ascending branch of the anterior circumflex humeral artery.
The shaft of the humerus is cylindrical above and triangular below, with three borders and three surfaces.
The posterior surface of the humerus has an oblique ridge and a radial groove containing the radial nerve and profunda brachii vessels.
The lower end of the humerus is broad and consists of an articular and non-articular part.
The capitulum of the humerus is rounded and convex, articulating with the trochlea of the ulna.
The radial fossa lodges the head of the radius during elbow flexion.
The determination of the side of the humerus can be made by the position of the head, lesser tubercle, intertubercular sulcus, and medial epicondyle.
Ossification of the humerus begins with one primary center for the shaft and additional secondary centers for the upper and lower ends.
Clinically, the humerus is susceptible to fractures, particularly at the surgical neck, shaft, and supracondylar region.
The most common dislocation of the shoulder joint is the inferior dislocation.
Transcripts
[Music]
humorus the humorus is the largest and
strongest long bone in the Upper Limb
the upper end consists of the head neck
greater tual lesser tubal and the
intertubercular
sulcus the head forms less than half of
a sphere and is smooth it is directed
medially backwards and
upwards it is covered by Hine articular
cartilage and articulates with the
glenoid cavity of the scapula to form
the shoulder
joint neck there are two necks
anatomical and
surgical the anatomical neck is the
constricted portion surrounding the head
it gives attachment to the capsule of
the shoulder joint except INF fom medial
surgical neck it is the junction between
the upper end and the shaft and is a
common site for
fractures the greater tubercle lies in
the posterior lateral aspect of the
upper end and forms the prominence of
the shoulder the medial margin gives
attachment to the transverse
ligament lesser tubercle is smaller than
the greater tubercle and lies in the
anterior aspect of the upper end just
above the surgical neck the lateral
margin gives attachment to the
transverse
ligament intertubercular sulcus it is
also known as the bicipital groove it is
a depression which lies between the two
tubes it consists of the medial lip
lateral lip and the
floor intertubercular sulcus contains
the long head of biceps brachi and the
ascending branch of the anterior
circumflex humoral artery the shaft is
like a cylinder above but flat and
triangular below it consists of three
borders anterior lateral and medial and
three surfaces anteromedial
anterolateral and
posterior the anterior border extends
from the lower end of the greater
tubercle till right above the radial
fosa the upper part forms the lateral
lip of the intertubercular
sulcus the lateral
border it extends from the greater
tubercle till the lateral
epicondylalgia medial border it extends
from the Lesser tubercle till the medial
epicondylar
sulcus it becomes prominent to form the
medial Supra condill line which gives
attachment to the medial intermuscular
septum the anterior lateral surface it
lies between the anterior and lateral
borders it presents a rough tubercle at
the middle called the deltoid
tuberosity anterior medial surface it
lies between the anterior and medial
borders a nutrient foramin is present
near the medial border and is directed
downwards hence the upper end is the
growing
end the posterior surface it lies
between the medial and lateral borders
an oblique Ridge is present in the upper
part the radial Groove the radial Groove
lies below the oblique Ridge runs down
and laterally till it reaches the
lateral border it contains the radial
nerve and the profunda brachi
vessels the lower end is Broad from side
to side and consists of an articular and
non-articular part articular part
capitulum it is rounded and convex and
lies latal to the proca and medial to
the lateral
epicondyle it is shaped like a pulley
and lies medial to the capitulum it
articulates with the trar notch of the
alna nonarticular part medial
epicondilite prominent than the lateral
epicondylus on its posterior surface for
the alar
nerve lateral
epicondilite of the lower
end the electron fosa it is a hollow
depression situated on the posterior
surface of the lower end its floor is
very thin hence may get perforated it
lodges the electron process of the alna
during extension of the
elbow coronoid fosa it is a small
depression situated just above the troca
it lodges the anterior margin of the
coronoid process of the alna during
elbow
flexion radial fosa it is a very small
depression lying lateral to the coronoid
fosa and above the capitulum it lodges
the head of the radius during elbow
flexion determination of the side the
head lies on the medial side of the
upper end and faces medially backwards
and upwards the Lesser tubercle projects
from the anterior part of the upper end
the intertubercular sulcus lies on the
lateral side of the lesser
tubercle the electron process lies on
the posterior side and the more
prominent medial
epicondyle
epicondilite the side they belong
to
oifc the humoris is aifi by one Primary
Center for the shaft three secondary
centers for the upper end and four
secondary centers for the lower end
upper end of
humoris the oifc for the head appears in
the first year for the greater tubercle
in the third year and lesser tubercle in
the fifth year the oifc center for the
shaft appears in the eighth week of
intra utrine
life lower end of the
humoris the center for capitulum and
lateral fange of the tra appears in the
second year medial part of the tra in
the 10th year lateral
epicondilite di in the sixth
year all the oifc centers in the upper
end fuse together by the seventh
Year all the oifc centers in the lower
end fuse together by 14 years of
life fusion with the
shaft the upper end joins with the shaft
by the 20th
year lower end joins with the shaft by
16 to 17 years and the medial
epicondilite by 18
years clinical
correlation nerves related to the
humoris are auxiliary nerve around the
surgical neck radial nerve in the radial
or spiral Groove and the olar nerve
behind the medial
epicondilite
common sites for the fracture of humorus
are surgical neck shaft and the suond
region
suond fracture of the humorus it is
caused by fall on an outstretched hand
and commonly occurs at a young age
clinically it presents as a backward
displacement of the lower fragment with
unduly prominent elbow this fracture May
injure the median nerve and the brachial
artery this location of the shoulder
joint is more common due to the capsule
being loose and the size of the head
being very large compared to the size of
the glenoid cavity the most common
dislocation of the shoulder joint is the
inferior dislocation
Browse More Related Video
How To Remember Every Muscle in the Upper Limb and Arm | Corporis
Osteology of Hip bone I Side side determination | Anatomical Position | Attachments | Applied
Stomach - gross anatomy
BMS 1 Anatomy: Musculoskeletal system for dentistry
Atlas & Axis Cervical Vertebrae (C1-C2) Anatomy
Muscles of the Upper Arm (glenohumeral and elbow joints)
5.0 / 5 (0 votes)