Surface Anatomy & dermatomes Flashcards
Name the 3 parts of the sternum
Manubrium
Body
Xiphoid process
What anatomical landmarks are found on the manubrium?
• The jugular notch forms its superior border.
Superolateral facet is for articulation with the clavicle Inferolateral facet is for articulation with the 1st rib via costal cartilage
The manubrosternal joint forms the inferior border. Second rib articulates at this level.
- Ribs can be counted from this level
Why can’t we start from rib 1 when counting ribs?
The first rib is concealed by the clavicle. The first palpable rib is rib 2, which articulates with the sternum at the manubrosternal joint.
Describe the body of the sternum
Made up of 4 fused segments
- Joints appear as ridges on the anterior surface
• Articular facets appear on lateral borders
- These articulate to costal cartilages of ribs 2-7
Which rib articulates with the xiphoid process?
Rib 7
What is meant by “true ribs”? And how many ribs are considered true ribs?
True ribs means ribs that articulate to the sternum directly. The firdt 7 ribs are true ribs.
What is meant by “false ribs”? How many ribs are false ribs?
False ribs do not articulate directly to the sternum. Rather, they articulate via the costal cartilage of rib 7. (Ribs 8-10 are false ribs).
What are floating ribs? And how many ribs are floating ribs?
Floating ribs do not articulate to the sternum at all. 2 ribs are floating ribs (ribs 11 and 12)
What is a subcostal angle?
Medial margin formed by costal cartilage - Costal cartilages of Ribs 8-10
• Diaphragm attaches to it anteriorly
Where is the breast located?
Between rib 2 and 6. It overlies the pectoralis major muscle.
Where is the mammary gland located?
The mammary gland extends superolaterally along the lower margin of the pec major muscle.
The _________________ connects the breast to the axilla
Axillary tail/process
Describe the right border of the heart
3rd costal cartilage
- ± Finger’s width to right of the sternum
• To 6th costal cartilage
Describe the left border of the heart
2nd intercostal space
- ± Finger’s width to left of the sternum
• To 5th intercostal space
- ± 9cm to left of the sternum - Midclavicular line
- Apex lies here
Describe the superior and inferior borders of the heart
Superior border
• 3rd costal cartilage
To 2nd intercostal space Inferior border
• 6th costal cartilage
• To 5th intercostal space
Describe the midaxillary line
Lateral vertical line along the coronal plane
- Beginning at the axilla and descends through abdomen
• Divides the body into anterior and posterior parts • Several structures found along this line
Describe the scapular line
Posterior vertical line along the sagittal plane
Line crosses the inferior angle of the scapula Several structures found along this line
Describe the Midclavicular line
Anterior vertical line along saggital plane
• Crosses costal margin at the 9th costal cartilage
• Extends from thorax to enter the thigh
- At the midpoint between ASIS and pubic tubercles - Referred to as the midinguinal line at this point
Describe the surface anatomy of lung borders
Rib 6 along the midclavicular line
- Rib 8 along the midaxillary line
- T10 along vertebral column
Describe the subcostal line
Superior horizontal line in the abdomen - Inferior to costal margins
• Lies at the inferior border of costal cartilage of Ribs 10
• Posteriorly, it passes through vertebral body of L3
Describe the intertubercular line
Inferior horizontal line in the abdomen
• Connect the tubercles of the iliac crests
- Tubercles are located posterior to ASIS
• Posteriorly, it passes through L5 vertebral body
- Passes through its upper part
List the 9 abdominal regions
Left and Right hypochondrium regions
Epigastric region
Left and right lumbar regions
Umbilical region
Left and right inguinal regions
Pubic region
What is the transumbilical line?
Horizontal line along transverse plane
• Crosses the umbilicus
- At the level of L3/L4
What is the median plane?
Vertical line dividing the body into left and right sides
Name the 4 quadrants of the abdomen
R and L upper quadrants
R and L lower quadrants
What are dermatomes?
Dermatomes are areas of skin supplied by - Single spinal cord level
- Single spinal nerve (Unilaterally)
• Formed from development of somites into the dermis
• Distribution overlap exists
- Most areas are supplied by a single spinal cord level
What does C2-8 supply?
Head (except face and calp), neck and upper limbs
What does the thoracic region supply?
Thoracic dermatomes (T1-T12)
the trunk
- T1 dermatome is mostly on the upper limbs
- T2 dermatome is the highest in the thorax
What does the lumbar region supply?
Mostly supplies anterior surfaces of the thighs and legs and dorsum of the foot
- Also supply the medial and lateral surfaces of the thighs and legs
- Part of the plantar surface of the foot
What does the sacral region supply?
Gluteal region
- Posterior surfaces of the thighs and legs
- S2-S4 dermatomes supply the perineum
- Plantar surface of the foot and part of the dorsum
The coccygeal region supplies_____________.
Skinof the anus
