Anatomy
Upper Limb
Your consultant asks you to examine the shoulder of a 35 year old man as he has some positive findings. The patient is unable to adduct, medially rotate and extend his shoulder. You suspect an injury or pathology to the nerve supplying the latissimus dorsi. The latissimus dorsi muscle is innervated by which of the following nerves:
Answer:
The latissimus dorsi is innervated by the thoracodorsal nerve.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 |
