The Innermost Layer of the Heart Wall Is the

question 22

Multiple Choice

The innermost layer of the heart wall is the

• A) mediastinum.
• B) parietal pericardium.
• C) epicardium.
• D) myocardium.
• E) endocardium.

---

Definitions:

Thylakoid Discs

Membrane-bound structures within chloroplasts where the light-dependent reactions of photosynthesis occur.

Granum

A stack of thylakoids within the chloroplasts of plant cells, crucial for the light reactions of photosynthesis.

Porphyrin Ring

A large, heterocyclic macrocycle composed of four modified pyrrole subunits interconnected via methine bridges, essential in the structure of heme groups and chlorophyll.

Magnesium

A chemical element with the symbol Mg, essential for living cells, playing a critical role in over 300 enzymatic reactions, including energy production.