1. Biology 211 Anatomy & Physiology I
The Brain

2. = = Central Brain Nervous Spinal cord System Nerves Peripheral Nervous

4. Human Central Nervous System
Starts as a groove which becomes a hollow tube in the embryo;
Remains hollow & fluid-filled
throughout life;
These fluid-filled spaces form the ventricles of the brain and the central canal of the spinal cord.
Cranial end of this hollow tube enlarges & folds to form brain and its various parts
Caudal end of this hollow tube does not enlarge or fold; Develops into spinal cord

5. Fifth week
Fourth week

6. Prosencephalon
Rhombencephalon
From your reading in Saladin and from lab, you should understand what adult structures form from the myelencephalon, metenchephalon, mesencephalon, diencephalon, and telencephalon

7. More terms you need to know for brain and spinal cord
Gray Matter: Nervous tissue of the CNS consisting of neuron cell bodies, their supporting glia, and unmyelinated axons & dendrites.
White Matter: Nervous tissue of the CNS consisting of myelinated axons & dendrites and their supporting glia
Cortex: On the surface of the brain
(only on cerebrum and cerebellum)
Nucleus: Deeper, surrounded by white matter

8. Coronal Section of Brain
Cross Section of Spinal Cord

9. The brain has seven major (and many minor) regions:
Cerebrum
Thalamus
Hypothalamus
Midbrain
Pons
Medulla Oblongata
Cerebellum
Brainstem
Let’s discuss each of these briefly.

10. Thalamus develops from diencephalon
Most nuclei are “relay centers”:
Receive sensory information
from spinal cord, other regions
of brain, eyes, ears, tongue,
nasal epithelium.
Relay that to sensory regions
of cerebral cortex
Some nuclei relay motor
information from cerebral cortex
to other regions of brain
Some nuclei regulate sleep/wakefulness
attention span

11. Hypothalamus develops from diencephalon
Some nuclei regulate body
temperature, blood pressure,
hunger, thirst, fatigue.
Some nuclei regulate endocrine
(hormone) functions by
controlling activity of pituitary
gland (to which it is
connected)

12. Midbrain develops from mesencephalon
Often still called that.
Some nuclei regulate eye
movement & visual reflexes.
Large tracts of white matter
(myelinated axons) pass
through, carrying motor
information from cerebral
motor cortex toward other
parts of brain and spinal cord.
Some nuclei modify that information to regulate motor functions.
Large tracts of white matter pass through, carrying sensory information from spinal cord toward thalamus.

13. Pons develops from metencephalon
Some nuclei relay signals
between cerebrum and
cerebellum.
Some nuclei help regulate sleep,
respiration, swallowing, taste,
hearing, bladder control,
equilibrium, eye movement,
facial expressions, facial
sensation, and posture.
Motor information from cerebral cortex (white matter) passes
through toward medulla oblongata and spinal cord;
Sensory information continues from the medulla oblongata and
spinal cord toward the thalamus and toward the cerebellum.

14. Cerebellum develops from metencephalon
Gray matter = cortex and nuclei
Receives motor information
from all parts of the brain,
including the cerebrum, and
Receives sensory information
from spinal cord and other
parts of the brain.
Uses that information to
coordinate and fine-tune movement, particularly timing
and precision.

15. Medulla Oblongata develops from myelencephalon
Some nuclei help regulate
respiration, heart rate, blood
pressure, blood distribution.
Other nuclei regulate vomiting,
swallowing, coughing,
sneezing, movement of
tongue
White matter carries motor
information from other regions
of brain to spinal cord, and sensory information from spinal
cord to other regions of brain.

16. Cerebrum
Arises from the telencephalon
Consists of right and left hemispheres separated by each other by the longitudinal fissure
Each hemisphere is hollow, containing a lateral ventricle which is lined by ependyma and filled with cerebrospinal fluid

17. Each hemisphere includes both white matter and gray matter:
Cerebrum
Each hemisphere includes both white matter and
gray matter:
Cortex
Basal Nuclei
Coronal Section

18. Cerebral Cortex
Gray Matter
2 - 4 mm thick
Folded into ridges, or gyri (singular: gyrus) separated by
shallow grooves, or sulci (singular = sulcus)
Different parts of brain separated by deep fissures

19. Lobes of Cerebral Cortex

20. Cerebral Cortex
Each gyrus, sulcus, and fissure has a name (more than 50 gyri & sulci)

21. Cerebral Cortex
Each gyrus, sulcus, and fissure has a name
You don't need to know all of them
You will need to know the following:
Longitudinal Fissure
Central Sulcus
Precentral Gyrus
Postcentral Gyrus
Lateral Fissure/Sulcus
Parietooccipital Sulcus

22. Different regions of the cortex have specific functions
Cerebral Cortex
Different regions of the cortex have specific functions
Three types of functional areas:
Motor
Sensory
Association
More about these in a moment – they form more than 75% of the cerebral cortex

23. Cerebral Cortex
Different regions of the cortex have specific functions
From your reading and lab exercises, you should know the functions of the following areas and where they are located:
Primary motor area
Motor association area
Primary somatosensory area
Somatosensory association area
Primary visual area
Visual association cortex
Primary auditory area
Auditory association area
Questions on these may be on lecture and/or lab exams

24. The “association” regions of the cerebral cortex also carry out the highly complex functions we associate with the brain.
Just a few examples:

25. Cerebral Cortex
Two regions of cortex important in language:
Broca's Area deals with formation of speech
Wernicke's Area deals with recognition and interpretation of speech
Both located primarily on
just one hemisphere
(usually the left).
Similar regions on other hemisphere control emotional content of speech.

26. Gray matter forms both:
Cerebrum
Recall::
Gray matter forms both:
Cortex
Basal Nuclei
Coronal Section

27. Basal or Deep or Cerebral Nuclei
Caudate
Putamen
Globus Pallidus
Claustrum
Amygdala
Not shown: Amygdala

28. Areas of the brain active in Parkinson’s Disease
Areas of the brain active in Huntington’s Disease

29. Keep in mind: All regions of the brain must work together, so there are many ways in which they communicate with each other.
Three examples (of many) of association area functions: The Reticular Formation
The Limbic System
Cerebellar Function

30. Many nuclei in the brainstem (midbrain, pons, medulla oblongata) are interconnected to form the
reticular formation.
It helps integrate sensory information from the spinal cord, eyes, ears, etc. with the motor information coming from the cerebrum, cerebellum, and other parts of the brain.
Thus, it plays a major role in coordinating all of the different parts of the nervous system.
It also plays a major role in coordinating the sleep/wake cycle and in habituation to frequent stimuli.

31. Different parts of the cerebrum (telencephalon) and the thalamus and hypothalamus (diencephalon) communicate with each other on the medial surface of each cerebral hemisphere to form the limbic system.
These coordinate emotions,
motivation, memory, and other functions important to survival of the individual (e.g. fear, anger, excitation, pleasure) or to survival of the species (sexual responses.)
The limbic system is closely linked to the sense of smell.

32. The cerebellum receives large amounts of motor information from the cerebral cortex, basal nuclei, and various parts of the brainstem. It also receives large amounts of sensory information coming from the spinal cord and brainstem.
It integrates this sensory input with the motor information to maintain balance and equilibrium and to coordinate both the timing and the intensity of voluntary movements

33. From your reading and lab exercises, you should also know the locations of the
- Lateral ventricles
- Interventricular
foramen
- Third ventricle
- Fourth ventricle
- Mesencephalic
aquaduct
- Median aperture
- Lateral apertures
Questions on these may be on lecture and/or lab exams

34. Brain is surrounded by three layers of connective tissue:
(Skull)
Epidural Space
Subdural Space
Subarachnoid Space
Dura Mater
Arachnoid Mater
Pia Mater

35. The brain is protected in three ways:
1) Skull
2) Meninges
Pia Mater
Arachnoid Mater
Dura Mater
3) Floats in cerebrospinal
fluid in subarachnoid
space

36. Cerebrospinal fluid produced within ventricles by specialized tissue called choroid plexus.
Flows toward fourth ventricle
Exits from fourth ventricle through three openings (apertures or foramina) into the subarachnoid space.
Median Aperture
Two Lateral Apertures
Surrounds brain & spinal cord.
Reabsorbed into blood
through arachnoid villi on surface of brain