When seen from an inferior view, many different features can be seen on the brain. The frontal lobe is anterior and the temporal lobe and cerebellum are visible as well. The cerebellum has small folds called folia. The medulla oblongata is attached to the spinal cord and the pons is anterior to the medulla oblongata. Anterior to the pons are the mammillary bodies which are responsible for the olfactory (smell) reflex. The pituitary gland is next to the mammillary bodies. Anterior to the pituitary is the optic chiasma, an x-shaped structure that has the optic nerves anteriorly and the optic tracts posteriorly. The olfactory tracts are seen in this view of the brain as two parallel structures on either side of the longitudinal fissure. The blood vessels of the brain are not visible in this illustration because they obstruct some of the neural structures. They are covered in the cardiovascular section. The cranial nerves will be covered in subsequent pages. Label the structures seen in an inferior view and color them in.
Answer Key: a. Frontal lobe, b. Cranial nerves, c. Optic chiasma, d. Pituitary, e. Temporal lobe, f. Mammillary body, g. Pons, h. Medulla oblongata, i. Cerebellum meclical 119
When the brain is sectioned in the midsagittal plane, many internal features are visible. One of the most obvious features is the crescent-shaped corpus callosum. Superficial to this is the cerebral hemisphere with the frontal lobe, parietal lobe, and occipital lobe. Locate the thalamus, hypothalamus, and mammillary body along with the optic chiasma and the pituitary gland. The pineal gland is a small structure at the posterior aspect of the thalamus. These structures are all part of the forebrain. The midbrain is a small section with the cerebral peduncles forming the inferior aspect of the midbrain and the cerebral aqueduct as a narrow tube between the peduncles and the corpora quadrigemina. The corpora consist of the superior colliculi which are responsible for visual reflexes and the inferior colliculi which are responsible for auditory reflexes. Posterior and inferior to the midbrain is the hindbrain. It consists of the pons, the cerebellum and the medulla oblongata. The pons is a large, oval-shaped structure. The cerebellum is visible with the arbor vitae (white matter of the cerebellum) and a triangular space known as the fourth ventricle. The medulla oblongata is the terminal part of the hindbrain. Label the features of the midsagittal section of the brain and color them in.
Answer Key: a. Optic chiasma, b. Mammillary body, c. Hypothalamus, d. Frontal lobe, e. Thalamus, f. Corpus callosum, g. Pineal gland, h. Parietal lobe, i. Superior colliculus, j. Cerebral aqueduct, k. Occipital lobe, I. Inferior colliculus, m. Cerebellum, n. Fourth ventricle, o. Medulla oblongata, p. Pons, q. Cerebral peduncle, r. Pituitary
When the brain is sectioned in the coronal plane, the convolutions are obvious. The gray matter is on the external aspect of the brain and the white matter is internal. There are deep sections of gray matter in the brain and these are known as basal nuclei. The external gray matter is known as the cerebral cortex and is divided into the gyri (raised areas)
and sulci (depressed areas). The longitudinal fissure is the deep cleft that separates the cerebral hemispheres. The cerebral hemispheres are connected by the corpus callosum. Deep in the hemispheres are spaces known as the lateral ventricles and the third ventricle is a space in the middle part of the brain. On the sides of the third ventricle is the thalamus and the floor of the third ventricle is the hypothalamus. The pituitary is suspended from the hypothalamus by the infundibulum.
Answer Key: a. Longitudinal fissure, b. Cerebral cortex (gray matter), c. Corpus callosum, d. Lateral ventricle, e. White matter, f. Thalamus, g. Third ventricle, h. Basal nuclei
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.