Anatomy
Upper Limb
An 85 year old man presents to the ED following a fall at home. On examination you note he is tender over the distal attachment of the latissimus dorsi and you suspect an underlying bony injury. The latissimus dorsi muscle inserts onto which of the following structures:
Answer:
The latissimus dorsi muscle inserts onto the floor of the intertubercular sulcus of the humerus.Latissimus Dorsi Muscle
Anatomy / Upper Limb / Pectoral Region
Last Updated: 8th April 2019
The latissimus dorsi muscle forms much of the muscle mass underlying the posterior axillary skin fold extending obliquely upwards from the trunk to the arm.
Table: Function and Innervation of the Latissimus Dorsi Muscle
| Muscle | Latissimus Dorsi |
|---|---|
| Origin | Spinous processes of lower 6 thoracic vertebrae and related interspinous ligaments; via the thoracolumbar fascia to the spinous processes of the lumbar vertebrae, related interspinous ligaments and iliac crest; lower 3 – 4 ribs |
| Insertion | Floor of intertubercular sulcus |
| Function | Adduction, medial rotation and extension of arm at glenohumeral joint |
| Innervation | Thoracodorsal nerve |
Origin
The latissimus dorsi originates from the spinous processes of the lower six thoracic vertebrae and related interspinous ligaments, via the thoracolumbar fascia to the spinous processes of the lumbar vertebrae, related interspinous ligaments and iliac crest and from the inferior 3 or 4 ribs.
Insertion
The muscle inserts onto the floor of the intertubercular sulcus of the humerus.
Function
The latissimus dorsi produces adduction, medial rotation and extension of the humerus at the glenohumeral joint.
Innervation
The latissimus dorsi is innervated by the thoracodorsal nerve.
![By Mikael Häggström (Image:Gray409.png) [Public domain or Public domain], via Wikimedia Commons](https://mrcemsuccess.com/wp-content/uploads/2016/12/Latissimus-Dorsi-649x1024.png)
Latissimus Dorsi Muscle. (Image by Mikael Häggström (Image:Gray409.png) [Public domain or Public domain], via Wikimedia Commons)
Report A Problem
Is there something wrong with this question? Let us know and we’ll fix it as soon as possible.
Loading Form...
- Biochemistry
- Blood Gases
- Haematology
| Biochemistry | Normal Value |
|---|---|
| Sodium | 135 – 145 mmol/l |
| Potassium | 3.0 – 4.5 mmol/l |
| Urea | 2.5 – 7.5 mmol/l |
| Glucose | 3.5 – 5.0 mmol/l |
| Creatinine | 35 – 135 μmol/l |
| Alanine Aminotransferase (ALT) | 5 – 35 U/l |
| Gamma-glutamyl Transferase (GGT) | < 65 U/l |
| Alkaline Phosphatase (ALP) | 30 – 135 U/l |
| Aspartate Aminotransferase (AST) | < 40 U/l |
| Total Protein | 60 – 80 g/l |
| Albumin | 35 – 50 g/l |
| Globulin | 2.4 – 3.5 g/dl |
| Amylase | < 70 U/l |
| Total Bilirubin | 3 – 17 μmol/l |
| Calcium | 2.1 – 2.5 mmol/l |
| Chloride | 95 – 105 mmol/l |
| Phosphate | 0.8 – 1.4 mmol/l |
| Haematology | Normal Value |
|---|---|
| Haemoglobin | 11.5 – 16.6 g/dl |
| White Blood Cells | 4.0 – 11.0 x 109/l |
| Platelets | 150 – 450 x 109/l |
| MCV | 80 – 96 fl |
| MCHC | 32 – 36 g/dl |
| Neutrophils | 2.0 – 7.5 x 109/l |
| Lymphocytes | 1.5 – 4.0 x 109/l |
| Monocytes | 0.3 – 1.0 x 109/l |
| Eosinophils | 0.1 – 0.5 x 109/l |
| Basophils | < 0.2 x 109/l |
| Reticulocytes | < 2% |
| Haematocrit | 0.35 – 0.49 |
| Red Cell Distribution Width | 11 – 15% |
| Blood Gases | Normal Value |
|---|---|
| pH | 7.35 – 7.45 |
| pO2 | 11 – 14 kPa |
| pCO2 | 4.5 – 6.0 kPa |
| Base Excess | -2 – +2 mmol/l |
| Bicarbonate | 24 – 30 mmol/l |
| Lactate | < 2 mmol/l |
