Human Anatomy: The Ribcage

Ribcage

The ribcage, also known as the thoracic cage, is a bony structure that forms the thorax.

Composition

• 12 pairs of ribs (true ribs and false ribs)
• 12 thoracic vertebrae (T1-T12)
• Sternum (breastbone)

Functions

• Protects the heart, lungs, and major blood vessels
• Provides a attachment site for muscles involved in respiration and movement
• Supports the upper back and aids in posture

Ribs

• True ribs (1-7): attach directly to the sternum
• False ribs (8-10): attach to the 7th rib via cartilage
• Floating ribs (11-12): do not attach to the sternum or any other ribs

Sternum

• Consists of three parts: manubrium, body, and xiphoid process
• Acts as a point of attachment for ribs and costal cartilages

Clinical Significance

• Rib fractures or injuries can lead to respiratory complications
• Thoracic outlet syndrome can occur when the thoracic cage compresses nerves or blood vessels

Ribcage

• The ribcage, also known as the thoracic cage, is a bony structure that forms the thorax.

Composition

• The ribcage consists of 12 pairs of ribs, 12 thoracic vertebrae (T1-T12), and the sternum (breastbone).

Functions

• The ribcage protects the heart, lungs, and major blood vessels.
• It provides a site for muscle attachment involved in respiration and movement.
• The ribcage supports the upper back and aids in posture.

Ribs

• True ribs (1-7) attach directly to the sternum.
• False ribs (8-10) attach to the 7th rib via cartilage.
• Floating ribs (11-12) do not attach to the sternum or any other ribs.

Sternum

• The sternum consists of three parts: manubrium, body, and xiphoid process.
• It acts as a point of attachment for ribs and costal cartilages.

Clinical Significance

• Rib fractures or injuries can lead to respiratory complications.
• Thoracic outlet syndrome can occur when the thoracic cage compresses nerves or blood vessels.

pH and pOH

• pH measures the concentration of hydrogen ions (H+) in a solution
• The pH scale ranges from 0 to 14, with 7 being neutral (neither acidic nor basic)
• Acidic solutions have a pH < 7 (high H+ concentration) and basic solutions have a pH > 7 (low H+ concentration)

The pH-pOH Relationship

• pOH measures the concentration of hydroxide ions (OH-) in a solution
• The pOH scale ranges from 0 to 14, with 7 being neutral (neither acidic nor basic)
• pH + pOH = 14 (at 25°C), indicating a inverse relationship between hydrogen and hydroxide ions

Buffers in Biochemistry

• A buffer is a solution that resists changes in pH when an acid or base is added
• Buffers are crucial in biochemistry to maintain optimal pH for enzyme activity and protein function
• Examples of buffers include phosphate buffer, bicarbonate buffer, and protein buffers

pH and Enzyme Activity

• Each enzyme has an optimal pH at which it is most active
• pH affects enzyme activity, as changes in pH can alter enzyme structure and function
• Examples of enzymes with specific optimal pH include:
  • Pepsin: optimal pH 2-3 (acidic) for protein digestion in the stomach
  • Amylase: optimal pH 6-7 (neutral) for starch breakdown in the mouth and small intestine