The choroid plexus consists of modified ependymal cells and is found within the walls of the cerebral ventricles and secretes cerebrospinal fluid. Plasma is the extracellular matrix of the blood. Urine is produced by the kidneys. Lymph is the excess fluid drained from the cardiovascular system, and mixes with blood at the level of the subclavian veins. 

The basal ganglia is a structure of the cerebrum that contains grey matter called the putamen, caudate nucleus, and globus pallidus. There are also two midbrain structures called the subthalamic nucleus and substantia nigra. 

The brain and spinal cord are protected by special membranes called meninges. The meninges are made up of three membranes listed from superficial to deep: dura mater, arachnoid mater, and pia mater. Note that the cerebrospinal fluid circulates in the space between the arachnoid mater and the pia mater, called the subarachnoid space.

The fourth ventricle is connected to the third ventricle via the aqueduct of Sylvius (also known as the cerebral aqueduct). The third ventricle connects with the lateral ventricles through the interventricular foramina. 

The medulla is part of the brain stem. The brain stem includes the medulla, pons, and midbrain. The medulla contains the ascending and descending tracts that communicate between the spinal cord and brain. The nucleus gracilis and nucleus cuneatus are two important nuclei found in the dorsal side of the medulla which receive sensory fibers from the fasiculus gracilis and fasiculus cuneatus. 

The two major components of the diencephalon are the thalamus and hypothalamus. The substantia nigra and subthalamic nucleus make up the basal ganglia while the midbrain and medulla are part of the brainstem. 

The corpus callosum is the band of myelinated fibers which connects the two cerebral hemispheres. Sulci is the general term for the grooves "valleys" in the brain. The cerebral aqueduct (aqueduct of Sylvius) carries cerebrospinal fluid from the third ventricle to the fourth ventricle. The longitudinal fissure is the deep groove that separates the left and right hemispheres of the brain. The lateral sulcus separates the frontal and parietal lobes of the brain from the temporal lobe.

Broca's area (motor speech area) is located in the left hemisphere of the frontal lobe. Broca's area controls all activities associated with speech production, including articulation and facial expression. However, recently it has been suggested that it also plays significant roles in speech comprehension. This is not to be confused with Wernicke's area, which is also in the left hemisphere of the frontal lobe, but is more associated with speech comprehension than speech production. 

Cerebrospinal fluid is found mainly in the four ventricles, where it is produced by the choroid plexuses. The choroid plexuses consist of capillary networks surrounded by ependymal cells of the neuroglia. The arachnoid villi are small protrusions in the venous sinuses of the brain (namely the superior sagittal sinus) that allow cerebrospinal fluid to drain back into the blood.

The medulla oblongata is part of the brainstem. It has chemoreceptors to detect changes in blood gasses, which is integrated and transformed via negative feedback by altering respiratory rate and aspects of cardiac function such as heart rate and cardiac output via the autonomic nervous system. Many reflexes are also carried out by the medulla including vomiting, coughing, sneezing, and swallowing. The hypothalamus regulates many other homeostatic parameters such as hunger, basal body temperature, circadian rhythm, thirst, fatigue, in addition to acting as the "master" of the pituitary gland, which secretes several hormones.