SG 15

BRAIN ANATOMY AND ORGANIZATION

1. The four main regions of the brain are the Cerebrum, Diencephalon, Brainstem, and Cerebellum.

2. Brain tissue can be classified as

   a. Gray matter which is composed of neuronal cell bodies, unmyelinated axons and dendrites

   b. White matter which is composed of myelinated axons. The color is due to the presence of myelin

3. Gray matter

   a. The outer region of gray matter is called the Cerebral Cortex

   b. The inner clusters of gray matters are called the Cerebral Nuclei

4. White matter

   a. The tracts that form the white matter can be classified as

   i. Commissural tracts which connect the two cerebral hemispheres

   ii. Association tracts which connect regions within the same hemisphere

   iii. Projection connect the brain to spinal cord

5. Gyri and sulcus

   a. The brain surface has folds called Gyri that are separated by Sulci

Cerebrum

6. The cerebrum has two hemispheres which are separated by a fissure (specific name not provided in the note).

7. Both hemispheres are connected by the corpus callosum.

8. Lobes

   a. Each hemisphere has five lobes which are Frontal Lobe, Parietal Lobe, Temporal Lobe, Occipital Lobe, and Insula.

   b. Frontal Lobe

   i. The frontal lobe is responsible for voluntary motor functions, decision making, personality, and (a fourth function is not explicitly listed in the provided notes).

   ii. The primary motor cortex is located in the (specific gyrus name not provided in the note) gyrus.

   1. This region is responsible for (specific function not provided in the note).

   2. The representation of the body on the primary motor cortex is called the (term not provided in the note).

   a. In this representation, the size of the brain region that is dedicated to a body part is proportionate to (information not provided in the note).

   b. The hand has a bigger brain region than the trunk (T/F) (information not provided in the note).

   iii. The frontal lobe is separated from the parietal lobe by the (specific sulcus name not provided in the note) sulcus.

   c. Parietal lobe

   i. The primary somatosensory cortex is located in the (specific gyrus name not provided in the note) gyrus.

   1. This region is responsible for touch, pain, temperature.

   2. The map of the body on the primary somatosensory cortex is called the (term not provided in the note).

   a. The size of the brain region is proportionate to (information not provided in the note).

   b. The thigh has a bigger brain region than the face (T/F) (information not provided in the note).

   d. Temporal lobe

   i. The temporal lobe is responsible for hearing and olfaction.

   e. Occipital lobe

   i. The occipital lobe is responsible for visual information.

   f. Insula

   i. The insula lobe is responsible for memory and taste interpretation.

9. Functional brain regions

   a. (Specific region name not provided in the note) is responsible for speaking and is located in the (specific lobe not provided in the note) lobe.

   b. (Specific region name not provided in the note) is responsible for understanding words and is located in the (specific lobes not provided in the note) lobes.

The Diencephalon

10. The diencephalon is made up of the Epithalamus, Thalamus, and Hypothalamus.

11. The epithalamus contains the pineal gland which produces a hormone called melatonin.

    a. This hormone helps to set body rhythms.

12. The thalamus sorts motor and sensory information.

    a. The medial geniculate is responsible for sorting (specific information not provided in the note) information.

    b. The lateral geniculate is responsible for sorting (specific information not provided in the note) information.

13. The hypothalamus controls (specific gland name not provided in the note) gland.

    a. Hypothalamic nuclei (specific names not provided in the note for functions listed):

    i. (Specific nucleus name not provided in the note) controls the circadian rhythm.

    ii. (Specific nucleus name not provided in the note) controls the body temperature (thermoregulation).

    iii. (Specific nucleus name not provided in the note) stimulates hunger.

    iv. (Specific nucleus name not provided in the note) suppresses your appetite.

The Brainstem

14. The brainstem is made up of the Midbrain, Pons, and Medulla Oblongata.

15. Mesencephalon

    a. The mesencephalon is also called the Midbrain.

    b. Cerebral peduncles are bundles of motor neurons on their way to the spinal cord.

    c. Midbrain is involved in the processing of pain (regulates pain pathways).

    d. (Specific structure name not provided in the note) makes a neurochemical called dopamine.

    i. Dopamine is a part of circuits that control (specific functions not provided in the note) and (specific functions not provided in the note), and addiction.

    ii. Damage to this region leads to (specific condition not provided in the note).

    e. The corpora quadrigemina is composed of the (superior colliculi not provided in the note) and (inferior colliculi not provided in the note).

    i. (Structure name not provided in the note) is involved in visual reflexes.

    ii. (Structure name not provided in the note) is involved in auditory reflexes.

16. Pons

    a. The pons works with the medulla oblongata to control respiration.

17. Medulla Oblongata

    a. The medulla oblongata is connected to the spinal cord inferiorly.

    b. (Specific structure name not provided in the note) are bundles of motor neurons on their way to the spinal cord.

    i. Decussation of the pyramids is responsible for (specific type of motor control not provided in the note) motor control.

    1. Because of the decussation, the muscles on the right side of the body are controlled by the (laterality not provided in the note) side of the brain.

    c. (Specific center name not provided in the note) center controls the heart rate.

    d. (Specific center name not provided in the note) center controls the diameter of the blood vessels.

    e. (Specific center name not provided in the note) center controls breathing.

    f. Other reflexes controlled by the medulla oblongata include (specific reflexes not provided in the note), swallowing and vomiting.

18. Reticular Formation

    a. The reticular formation runs through the brainstem.

    b. The reticular formation is critical for filtering (information type not provided in the note) and for the control of sleep.

Cerebellum

19. The cerebellum contains two hemispheres which are connected by the vermis.

20. Each cerebellar hemisphere contains three lobes which are (specific lobe names not provided in the note).

21. The cerebellum is connected

    a. to the pons by the (specific peduncle name not provided in the note).

    b. to the mesencephalon by the (specific peduncle name not provided in the note).

    c. to the medulla oblongata by the (specific peduncle name not provided in the note).

22. The cerebellum is involved in our sense of equilibrium and in fine-tuning motor movements.

Meninges

23. Meninges are membranes that cover the brain and (No information on Meninges is provided in the given notes).

24. The deepest meningeal layer is the (No information on Meninges is provided in the given notes).

25. The middle meningeal layer is the (No information on Meninges is provided in the given notes).

26. The most superficial meningeal layer is the (No information on Meninges is provided in the given notes).

27. The dura mater

    a. The dura mater has two layers

    i. The (No information on Meninges is provided in the given notes) is next to the skull and the (No information on Meninges is provided in the given notes) is next to the arachnoid mater.

    b. Dural venous sinuses are formed by the separation of the (No information on Meninges is provided in the given notes) and (No information on Meninges is provided in the given notes).

    i. Dural venous sinuses transport (No information on Meninges is provided in the given notes) and (No information on Meninges is provided in the given notes).

    c. Dural septa are formed by the (No information on Meninges is provided in the given notes).

    i. The (No information on Meninges is provided in the given notes) runs in the longitudinal fissure.

    ii. The (No information on Meninges is provided in the given notes) runs on top of the vermis.

    iii. The (No information on Meninges is provided in the given notes) runs in the transverse fissure.

    iv. The (No information on Meninges is provided in the given notes) covers the sella turcica.

28. Arachnoid mater

    a. (No information on Meninges is provided in the given notes) space is located between the (No information on Meninges is provided in the given notes) and the (No information on Meninges is provided in the given notes).

    i. (No information on Meninges is provided in the given notes) flows inside this space.

Ventricles and CSF

29. The brain has (number of ventricles not provided in the note) ventricles which are

    a. 2 (specific names not provided in the note) that are located in the cerebrum.

    b. 1 (specific name not provided in the note) that is located in the diencephalon.

    c. 1 (specific name not provided in the note) that is located in the brainstem.

30. The (specific ventricle name not provided in the note) ventricle is continuous with the (specific structure name not provided in the note) of the spinal cord.

31. The ventricles contain choroid plexus which produces cerebrospinal fluid.

32. Path of CSF (Detailed path information not provided in the note).

    a. CSF from lateral ventricles flows through the (specific structure name not provided in the note) to enter the third ventricle.

    b. From the third ventricle, CSF flows through the (specific structure name not provided in the note) to enter the fourth ventricle.

    c. From the fourth ventricle, CSF flows through (specific structure name not provided in the note) to enter the subarachnoid space.

    i. Some CSF from the fourth ventricle also enters the (specific structure name not provided in the note) of the spinal cord.

    d. CSF leaves the subarachnoid space by flowing through (specific structure name not provided in the note) to enter the (specific structure name not provided in the note).

33. Three functions of CSF are Buoyancy, Protection, and Circulation (or "is replaced regularly").

Development of the Nervous System

34. Brain develops begin at approximately (No information on the Development of the Nervous System is provided in the given notes) of pregnancy from a embryonic structure called the (No information on the Development of the Nervous System is provided in the given notes).

35. The three primary brain vesicles are (No information on the Development of the Nervous System is provided in the given notes), (No information on the Development of the Nervous System is provided in the given notes), and the (No information on the Development of the Nervous System is provided in the given notes).

36. The secondary vesicles are

    a. (No information on the Development of the Nervous System is provided in the given notes) and (No information on the Development of the Nervous System is provided in the given notes) which come from the prosencephalon.

    b. (No information on the Development of the Nervous System is provided in the given notes) and (No information on the Development of the Nervous System is provided in the given notes) which come from the rhombencephalon.

    c. (No information on the Development of the Nervous System is provided in the given notes) remains the same.

37. Final Brain Structure

    a. The cerebrum develops from the (No information on the Development of the Nervous System is provided in the given notes).

    b. Thalamus, hypothalamus, epithalamus and retina develop from the (No information on the Development of the Nervous System is provided in the given notes).

    c. Midbrain develops from (No information on the Development of the Nervous System is provided in the given notes).

    d. Pons and cerebellum develop from (No information on the Development of the Nervous System is provided in the given notes).

    e. Medulla oblongata develops from (No information on the Development of the Nervous System is provided in the given notes).