Anatomy And Physiology Advanced - Qp7

Cerebrospinal fluid (CSF) is a clear fluid that surrounds the brain and spinal cord, acting as a protective cushion. It helps to absorb shocks and impacts, preventing direct contact between the brain/spinal cord and the skull/vertebrae. CSF also helps to regulate the pressure around the central nervous system and provides nutrients to the brain and spinal cord. Therefore, it is correct to say that cerebrospinal fluid protects the brain and spinal cord.

During early development, the cavity of the brain becomes divided into three parts by constrictures. These three parts are known as the forebrain, midbrain, and hindbrain. The forebrain is responsible for various functions such as sensory perception, conscious thought, and voluntary actions. The midbrain plays a role in relaying sensory and motor information and is involved in functions like visual and auditory processing. The hindbrain controls vital functions such as breathing, heart rate, and coordination of movement.

The given statement is false. The brain does not weigh between two and six kilograms. The average weight of an adult human brain is about 1.4 kilograms or 3 pounds. The weight can vary slightly depending on factors such as age, sex, and overall body size, but it generally falls within this range.

The reflex centres in the medulla oblongata control food and air passages and produce automatic reflex actions such as swallowing, vomiting, coughing, and sneezing. These reflex actions are involuntary and occur without conscious thought or control. The reflex centres in the medulla oblongata receive sensory input from various parts of the body and coordinate the appropriate motor response to ensure the safety and proper functioning of the respiratory and digestive systems.

The statement is true because the central nervous system, which includes the brain and spinal cord, is responsible for controlling and coordinating the activities of the body, including voluntary movements. Voluntary muscles are those that we have conscious control over, such as those used for walking or picking up objects. The central nervous system sends signals to these muscles, causing them to contract and produce movement.

Motor fibers do not run towards a point at the center of the base of the cerebrum. Instead, they originate from the motor cortex in the cerebrum and extend downward through the brainstem, forming the corticospinal tracts. These tracts then pass through the midbrain, pons, and medulla before reaching the spinal cord. Therefore, the statement is false.