Which bones make up the pectoral girdle?

A. Medulla oblongata: The medulla oblongata controls autonomic functions such as heart rate, breathing, and blood pressure. It is not primarily responsible for coordination or balance.

B. Cerebrum: The cerebrum manages higher brain functions, including thought, memory, and voluntary movement planning. While it initiates movement, it does not directly coordinate balance or fine motor control.

C. Hypothalamus: The hypothalamus regulates homeostatic processes like temperature, hunger, thirst, and hormonal control. It is not involved in motor coordination or balance.

D. Cerebellum: The cerebellum coordinates voluntary movements, maintains posture, and ensures balance and equilibrium. It processes input from sensory systems and the cerebrum to fine-tune motor activity, making it essential for coordinated movement.

A. Transmit electrical impulses: Transmission of electrical impulses along neurons is the function of the neurons themselves, not Schwann cells. Schwann cells support this process but do not directly carry impulses.

B. Form myelin sheaths around axons: Schwann cells do form the myelin sheath in the peripheral nervous system, which insulates axons and speeds up signal conduction. However, in the context of nerve repair, their guiding role is more critical.

C. Generate neurotransmitters: Neurotransmitters are produced by neurons at synaptic terminals to facilitate communication between cells. Schwann cells do not synthesize neurotransmitters.

D. Guide the regeneration of nerve fibers: During nerve injury, Schwann cells play a key role in repair by forming bands of Büngner that guide regrowing axons toward their target tissues. They also secrete growth factors that support axonal regeneration, making them essential for nerve fiber repair.