KA-Organ Systems

Question 1

What are the two main parts of the nervous system?

Answer 1

1. Central Nervous System (CNS): consists of the brain, spinal cord, and optic nerves.
2. Peripheral Nervous System (PNS): The PNS consists of the nerves and ganglia outside of the brain and spinal cord. It includes the cranial nerves, spinal nerves and their roots and branches, peripheral nerves, and neuromuscular junctions.

Question 2

Brain Stem

Answer 2

The central trunk of the mammalian brain, consisting of the medulla oblongata, pons, and midbrain, and continuing downward to form the spinal cord.

The brainstem is the posterior part of the brain, adjoining and structurally continuous with the spinal cord.

The Brain Stem evolved 500 million years ago and is the most ancient part of the brain. It is composed of the hindbrain, plus the midbrain, minus the cerebellum. It is involved in alertness and in monitoring basic survival functions such as breathing, heartbeat, and blood pressure. It is also known as the “reptilian brain” because it is considered the entire brain of reptiles.The Brain Stem evolved 500 million years ago and is the most ancient part of the brain. It is composed of the hindbrain, plus the midbrain, minus the cerebellum. It is involved in alertness and in monitoring basic survival functions such as breathing, heartbeat, and blood pressure. It is also known as the “reptilian brain” because it is considered the entire brain of reptiles.

Question 3

What three major regions can the brain be divided into?

Answer 3

1. Forebrain (prosencephalon): composed of the cerebrum–it is the rostral-most (forward-most) portion of the brain–this region is involved in processing complex information. Composed of the limbic system, thalamus, hypothalamus, the basal ganglia, and the cerebral cortex.
2. Midbrain (mesencephalon): The midbrain comprises the tectum, tegmentum, the cerebral aqueduct, and the cerebral peduncles. It is a portion of the central nervous system associated with vision, hearing, motor control, sleep/wake, arousal (alertness), and temperature regulation.
3. Hindbrain (rhombencephalon): the lower part of the brainstem, comprising the cerebellum, pons, and medulla oblongata.