Cranium, Scalp, Meninges, and Brain (part 2) Flashcards
Outline for Lecture:
- Brain development
- Major lobar arrangement of cerebrum
- Primary functional regions and association areas
- Tracts, nuclei and their functions
- Organization and function of diencephalon and brain stem
What is housed in the gray matter of brain tissue?
- Motor neurons
- Interneuron:
> cell bodies
> dendrites
> axon terminals
> unmyelinated axons
What is white matter composed primarily of?
Myelinated axons.
Druing brain development, an outer, superficial region of gray matter form from what?
Migrating peripheral neurons.
External sheets of gray matter, called the cortex, cover the surface of what?
Most of the adult brain (the cerebrum and cerebellum).
What are the three initial brain vesicles?
- prosencephalon - “forebrain”
- mesencephalon - “midbrain”
- rhombencephalon - “hindbrain”
By what week in development have the three initial brain vesicles differentiated by?
end of the 4th week
List the five secondary brain vesicles.
- telencephalon - from prosencephalon, forms the cerebrum.
- diencephalon - from prosencephalon, forms the thalamus, hypothalamus, and epithalamus
- mesencephalon - remains as in week 4
- metencephalon - from the rhombencephalon, forms the pons and cerebellum
- mylecephalon - from the rhombencephalon, forms the medulla oblongata
When are the components of the secondary brain vesicles differentiated by during development?
5th week
What does the telencephalon form?
cerebrum
What does the diencephalon form?
thalamus, hypothalamus, and epithalamus
What does the mesencephalon form?
mesencephalon
What does the metecephalon form?
pons and cerebellum
What does the mylencephalon form?
medulla oblongata
What are the 4 major regions of the brain?
- cerebrum
- diencephalon
- brainstem
- cerebellum
What is the cerebrum divided into?
Two halves - left and right cerebral hemispheres.
what is each hemisphere subdivided into?
five functional areas called lobes
What does the outer surface of an adult brain exhibit?
Folds called gyri (gyrus) and shallow depressions between those folds called sulci (sulcus).
How many pairs of cranial nerves is the brain associated with?
12
What makes up the brainstem?
- midbrain
- pons
- medulla (oblongata)
What is the primary function of the frontal lobe?
> higher intellectual functions (concentration, decision making, planning):
- personality
- verbal communication
- voluntary motor control of skeletal muscles
What is the primary function of the parietal lobe?
> Sensory interpretation of textures and shapes.
> Understanding speech and formulating words to express throughts and emotions (Wernicke’s area).
What is the primary function of the temporal lobe?
> Interpretation of auditory and olfactory sensations.
> Storage of auditory and olfactory experiences.
What is the primary function of the occipital lobe?
> Conscious perception of visual stimuli.
Integration of eye-focusing movements.
Correlation of visual images with previous visual experiences.
What is the primary function of the insula?
> Interpretation of taste.
> Memory
Where is the premotor cortex located and what does it do?
> frontal lobe
> coordinates learned skilled motor activities (e.g. playing the piano)
Where is the somatosensory association area located and what does it do?
> parietal lobe
> integrates and interprets sensations to determine the texture, temperature, pressure, and shape of objects
True or False:
Primary motor and sensory cortical regions are connected to adjacent association areas that process and interpret incoming data or coordinate a motor response.
True
Where is the auditory association area located and what does it do?
> temporal lobe
> interpret characteristics of sound and stores memories of sounds heard in the past (“ear worm”)
Where is the visual association area located and what does it do?
> occipital lobe
> process visual info by analyzing color, movement, and form to identify things we see
What are the two functional brain regions that have multiassociation areas?
> Wernicke’s area
> Gnostic area
Where is the Wernicke’s area located and what does it do?
> left hemisphere
recognize, understand, and comprehend spoken or written language.
- works with Broca’s area which is the motor speech area
Where is the gnostic area located and what does it do?
> parietal, occipital, and temporal lobes
> E.g., clock indicates 12:30, smell food cooking, friend talks about hunger, you interpret it to be lunch time.
What do association tracts connect?
Different regions of cerebral cortex within the same hemisphere.
What do commissural tracts do?
Connect the left and right cerebral hemispheres.
What do projection tracts link?
Cerebral cortex to the caudal brain regions (e.g., corticospinal tract from cerebrum to brainstem and spinal cord).
Are tracts in the brain white or gray matter?
central white matter