Why do individuals who suffer from brainstem injuries have difficulty with their autonomic functions?

Answer: The brainstem controls autonomic functions through cranial nerves arising from it, along with the medulla oblongata, therefore an injury to the area can cause loss of these functions.

Explanation:

The brainstem comprises of the midbrain, and the pons and medulla of the hindbrain. It is in direct continuation with the spinal cord. Ten cranial nerves arise from this part, and a number of tracts pass through this region. The medulla of the brainstem are particularly involved in maintaining heart rate, breathing and blood pressure. In case of a brainstem injury, the cranial nerves responsible for autonomic functions could get damaged leading to dysfunction and/or the areas of medulla consisting of centres controlling heart rate, blood pressure or other autonomic functions, if damaged could cause difficulties.

Because the brainstem regulates autonomic functions through cranial nerves arising from it.

Explanation:

The brainstem is the posterior part of the brain that is continuous with the spinal cord. The brainstem has three parts which includes; midbrain, pons and medulla oblongata.

The midbrain play major part in wakefulness and regulation of homeostasis. It is associated with vision, hearing, motor control, sleep and wake cycles, alertness, and temperature regulation.

The pons is situated between the medulla oblongata and the midbrain. It transmit signal information via nerves to the cerebrum through the medulla and to the cerebellum. It also sends sensory signals to the thalamus via sensory nerves. The pons performs both motor and sensory functions. Sensory functions like hearing, equilibrium, taste, and facial sensations such as touch and pain. Motor roles like eye movement, facial expressions, chewing, swallowing, urination, and the secretion of saliva and tears.

The medulla oblongata controls autonomic functions and connects the spinal cord to higher levels of the brain. It also regulate several basic functions of the autonomic nervous system like breathing, heart and blood vessels, digestion, vomiting, coughing, sneezing, and swallowing.

Individuals that suffers Injury to the brainstem, particularly to the medulla oblongata, will have difficulty with these autonomic functions.