Describe the 2 homeostatic control mechanisms with examples

Here are the answers to the remaining questions:

Section B: Short answer structural questions

5. State 4 characteristics of epithelia tissues? (2 marks) Four characteristics of epithelial tissues are:
   • Polarity: They have distinct apical (free) and basal (attached) surfaces.
   • Specialized contacts: Cells fit closely together to form continuous sheets, bound by tight junctions and desmosomes.
   • Supported by connective tissue: They are always supported by an underlying layer of connective tissue.
   • Avascular but innervated: They lack blood vessels but are supplied by nerve fibers.
   • Regeneration: They have a high capacity to regenerate and replace lost cells.

SECTION C: Short essay (10 marks)

1. Describe the 2 homeostatic control mechanisms with examples The two main homeostatic control mechanisms are negative feedback and positive feedback.

   • Negative feedback is the most common mechanism, working to reverse or reduce the intensity of the original stimulus, bringing the body back to its set point. For example, when body temperature rises, negative feedback mechanisms (like sweating and vasodilation) work to lower it back to normal.
   • Positive feedback enhances or exaggerates the original stimulus, pushing the variable further in the same direction. This mechanism is less common and typically controls events that are self-limiting and need to be completed quickly. An example is childbirth, where uterine contractions stimulate the release of oxytocin, which in turn increases the strength of contractions until the baby is delivered.

2. Superior, Inferior, Anterior, Posterior, Lateral, Medial, Proximal, Distal, Superficial, Deep (Fill the blank spaces with the available options) a. The ankle is Distal to the knee b. The nose is Medial to the ear c. The backbone is Posterior to the heart d. The nose is Superior to the chin e. The stomach is Inferior to diaphragm f. The nose is located on the Anterior surface of the body g. The lungs are Lateral to the heart h. The elbow is Proximal to the wrist i. The skin is Superficial to the bones j. The bones is Deep to the muscles