The Brain Flashcards
Neural Tube
Walls of the tube forms the brain’s six divisions.
- forms all cells found in the brain and spinal cord, walls become neurons and glial cells, and hollow cavity becomes the central canal and ventricles in the brain
Ventricles
- Chambers traveling down brain’s embryological center to spinal cord
- Contains CSF and distributes nourishments and protects brain
Choroid Plexuses
Specialized blood vessel that makes the CSF
Lateral Ventricles (2)
- cerebral hemispheres
- separated by thin membrane called the septum pellucidum
- interconnected hollow cavities that house CSF
Septum Pellucidum
Thin membrane that separates the lateral ventricles
Interventricular Foramen
What the 2 lateral ventricles lead into and it opens to the third ventricle
Third Ventricle
- deep in the diencephalon
-narrows inferiorly to form the cerebral aqueduct
Cerebral Aqueduct
Travels through the midbrain and connects with the fourth ventricle
Fourth Ventricle
- found between the pons and cerebellum
- large, diamond-shaped expansion
- as it narrows inferiorly, it joins the central canal of the medulla and spinal cord
Central Canal
Passes through the medulla and into the spinal cord
Meninges
Series of membranes
- Dura Mater: most superficial and provides a resilient layer around the brain - 2 sub layers divide to form dural venous sinuses (veins that drain blood from brain and scalp)
- Arachnoid mater: innermost surface of the dura and its fine strands extend across subarachnoid space (filled w/ CSF = watery cushion for brain) to pia mater
- Pia Mater: deepest meninx
CSF
1) CSF enters ventricles from choroid plexuses
2) CSF travels from ventricles to the subarachnoid space
3) CSF absorbed by arachnoid granulations (out-pocketings of the arachnoid mater) and enters the dural venous sinuses
Organization of the Brain
1) Nuclei: central gray matter
2) Ventricles: fluid-filled cavities surrounded by nuclei
3) Cortex: additional superficial region of gray matter
4) white matter containing axons travel to and from the brain’s nuclei and cortex and are ordered into tracts
Commissural Tracts
Connect the right and left sides fo the brain
Projection Tracts
Connect higher and lower regions of CNS. Ascending or descending depending on information flow.
- interneurons of the corticospinal and spinothalamic pathways
Association Tracts
Found in cerebrum and connect one part of the cortex to adjacent regions of the same hemisphere
Cerebral Hemisphere Lobes
1) Frontal
2) Parietal
3) Occipital
4) Temporal
5) Insular - tucked away in lateral sulcus
Gyri
Ridges that cover surface of cerebrum
Sulci
Grooves that cover cerebrum’s surface
Fissures
Major grooves that cover the cerebrum’s surface
Longitudinal Fissure
Separates the right and left hemispheres
Central Sulcus
Divides the frontal and parietal lobes
Lateral Sulcus
Divides the temporal from frontal and parietal lobes
Parieto-occipital Sulcus
Divides the parietal and occipital lobes
Primary Motor Cortex
At the precentral gyrus and is responsible for initiating voluntary movement throughout the body by sending instructions down the brain to the motor division of the PNS=
Primary Somatosensory Cortex
Where the body’s general senses arrive and is located on the postcentral gyrus of the parietal lobes
Primary Visual Cortex
Neurons from the special senses project to the Occipiatal Lobe
Primary Auditory Cortex
Temporal Lobe
Primary Olfactory Cortex
Temporal Lobe
Primary Gustatory (taste) Cortex
Parietal and Insular Lobes
Multimodal Association Areas
Found throughout the cortex and integrate inputs from multiple senses
Prefrontal Cortex
Important in social interactions and personality
Diencephalon Structures
Thalamus, Hypothalamus, Pineal Gland
Pineal Gland
Produces Melatonin
Thalamus
Relay station of the brain because its the synapse site for nearly all sensory pathways: signals routed from the spinal cord or lower brain regions to the appropriate regions of the cerebral cortex
Hypothalamus
Below the thalamus and has several nuclei containing: autonomic control centers, body control center, sleep cycle control center, emotional control center
- responds to stimuli in the brain by releasing hormones that control the pituitary gland
Pituitary Gland
Structure found suspended from the hypothalamus and produces hormones that control the thyroid, adrenal cortex, liver and reproductive function
Midbrain
Narrow region between the pons and thalamus and contains some nuclei and lots of white matter
-cerebral peduncles
-corpora quadrigemina
Cerebral Peduncles
Large bundles containing projection tracts and allow communication b/w the cerebral hemispheres and lower parts of the CNS
Corpora Quadrigemina
- Superior Colliculi: nuclei on posterior side of midbrain, initiates visual reflexes like the coordination of eye and head movements when tracking a moving object.
- Inferior Colliculi: nuclei on posterior midbrain, receives auditory info and coordinates reflexive actions in response to sounds
Pons
- tracts of white matter
Cerebellar Peduncles
Large bundles that other tracts arriving at the pons enter the cerebellum through
Medullary pyramids
Large ridges on the anterior surface of the medulla oblongata that contain the descending corticospinal tracts that contain axons directing voluntary movements of the body
- several nuclei
Nuclei Centers
- Cardiovascular Centers: regulate heart rate and blood vessel diameter
- Respiratory Centers: control depth and rate of breathing
- Various Autonomic Centers: reflex centers for the gastrointestinal tract
Cerebellum
- little brain
- cerebellar hemispheres: look like smaller version of cerebral hemispheres
- outer cortex and inner white matter
- above: informed about intent to initiate movements (cerebral hemispheres)
- below: receives info from sensory receptors in muscles and joints that provide info about body’s position
Arbor Vitae
Tree-like branching pattern of white matter from cerebellum when viewed from midsagittal section
Vermis
Midline lobe at the center of the cerebellum
Limbic System
Includes parts of the cerebral cortex, thalamus, and hypothalamus. Coordinate to recognize social cues and elicit emotions and memories
Reticular Formation
Limits sensory information from reaching the conscious mind
Cerebrum
Basal Nuclei: lies close to lateral ventricles in deepest recesses of cerebral hemisphere. Gray Matter clusters (regulate movement initiation and coordinated control of antagonistic muscle pairs)
Internal Capsule
Basal nuclei clustered into 2 main bodies and separated by the large bundles of projection and association tracts (internal capsule)
Globular Amygdala and Elongate Hippocampus
- Inferior and lateral to basal nuclei and internal capsule
- Involved in memory
- Amygdala: decision-making and emotional responses
- Hippocampus: spatial memory and navigation
Corpus Callosum
At the midline of the brain and is a massive bundle of white matter containing axons responsible for communication b/w cerebral hemispheres
- largest commissural tracts
