Lecture 2 Flashcards
Describe the difference in directional orientation systems found within the central nervous system.
Brain - top: dorsal - front - rostral - back - caudal - bottom - ventral Spinal Cord - top: rostral - front: ventral - back: dorsal - bottom: caudal
What are the 3 planes used to orient images in the central nervous system?
sagittal, coronal/frontal, horizontal/transverse
What structures make up the prosencephalon (and how are they further divided into the telencephalon and diencephalon)?
telencephalon - cerebral hemispheres, subcortical white matter, basal ganglia, basal forebrain nuclei
diencephalon - thalamus, hypothalamus, and epithalamus
What structures make up the mesencephalon?
cerebral peduncles, midbrain tectum, and midbrain tegmentum
What structures make up the rhombencephalon (and how are they further divided into the mesencephalon and myelencephalon)?
mesencephalon - pons and cerebellum
myelencephalon - medulla oblongata
Explain the difference between gray and white matter.
gray matter - neuron bodies, dendrites, axon terminals - majority of local synaptic communication
white matter - myelinated axons - majority of signal transmission
Define gyrus, sulcus and fissures with regards to central neuroanatomical structures.
- gyrus - ridges
- sulci - grooves
- fissures - big sulci
What is the function of the cranial vault and what bones comprise it?
- provide protection of brain and support facial structures
- total of 22 bones
- cranium (8) - frontal, 2 parietal, 2 temporal, 2 sphenoid, occipital
- facial bones (14)
What is regarded as a fossa in the cranial vault? What are the major fossae found in the human skull?
fossa - cavity/compartment
- anterior fossa - frontal lobe
- middle fossa - temporal lobe
- posterior fossa - cerebellum, brainstem
What function does a foramen hold in the skull?
openings in which cranial nerves, arteries, veins, and other structures pass
Identify the boundaries of the vertebral column. What runs through here?
- boundaries - vertebral body and vertebral arch (pedicles, laminas)
- spinal cord
Identify the boundaries of the intervertebral column. What runs through here?
- boundaries - vertebral body, intervertebral disc, facet joint, inferior notch of pedicle, and superior vertebral notch of pedicle below
- spinal nerve roots
What are the names of the meninges, and how are they oriented travelling superficially to deep?
dura mater, arachnoid mater, pia mater
What is the dura mater composed of? What is its role?
- periosteal layer (fused w/ skull) and meningeal layer (fused w/ periosteal layer)
- envelop and protect brain
- limit rotational displacement of brain
- Regulate generation and migration of neural progenitors
- Regulates proliferation and survival of radial glial cells
Describe the structural layout of the arachnoid mater. What is its role?
- web-like appearance with space in-between filled w/ CSF
- envelop and protect brain
- combats shearing of brain
- aids in CSF circulation
What is the role of the pia mater?
- Envelop and protect brain
- Aids in production of CSF
- Embeds superficial arteries and veins and serves as separation between neural tissue and blood vessels
↑ efficiency of blood brain barrier - Contributes to degradation of neurotransmitters
Define the spaces associated with the meninges. What is their function within the skull?
- epidural space and subdural space - too small to see unless pathology
- subarachnoid space - contains connective tissue trabeculae and intercommunicating channels w/ CSF; also houses superficial branches of cerebral arteries and veins
What is cerebrospinal fluid (CSF) composed of?
clear, colorless alkaline fluid w/ H2O, glucose, proteins, electrolytes, etc.
Where is CSF secreted, and what structures? Where is it reabsorbed?
- secreted by choroid plexus found in ventricles
- reabsorbed by arachnoid granulations
What are the functions of CSF?
- support and protect brain/spinal cord
- maintain pressure
- nutrition
- waste removal
What role does ventricles play in the CSF system? Where are they found?
- produce and distribute CSF
- lateral ventricle - cerebral hemisphere
- 3rd ventricle - thalamus and hypothalamus
- 4th ventricle - pons, medulla, and cerebellum
What is the route that CSF takes as it travels through the nervous system?
lateral ventricles - intraventricular foramen - 3rd ventricle - cerebral aqueduct of Sylvius - 4th ventricle - medial and lateral foramen - subarachnoid space of spinal cord/brain - arachnoid granulations
What is the role of the blood brain barrier?
barrier between bloodstream and extracellular space of brain
What types of material does the blood brain barrier allow in? What does it block?
- allows in: water, O2, small lipid-soluble substances
- blocks: toxins, pathogens, other potentially dangerous substances
- allows nicotine, alcohol, anesthesia across
Where can the blood brain barrier be found?
brain’s blood vessels
What are the 4 major sets of lobes found in the cerebrum?
- frontal
- parietal
- temporal
- occipital
Where are the frontal lobes located? What major regions make up this area?
- rostral to central sulcus and medial to Sylvian fissure
- prefrontal cortex, primary motor cortex and supplementary motor areas, frontal eye fields, Broca’s Area (motor speech)
Where are the parietal lobes located? What major regions make up this area?
- caudal to central sulcus to parieto-occipital sulcus, medial to Sylvian fissure
- primary somatosensory cortex and supplementary somatosensory areas, perceptual integration, visual and auditory processing and integration, Wenicke’s Area (speech comprehension)
Where are the temporal lobes located? What major regions make up this area?
- lateral to Sylvian fissure
- primary auditory center and auditory association cortex, visual processing regions, memory
Where are the occipital lobes located? What major regions make up this area?
- caudal to parieto-occipital sulcus
- primary visual cortex and visual association cortex
Where can the major primary cortices be found?
- primary motor cortex - precentral gyrus
- primary somatosensory cortex - postcentral gyrus
- primary auditory cortex - transverse gyri of Heschl
- primary visual cortex - along the banks of Calcarine fissure
What does it mean to be somatotopically represented?
orients the specific body part and their respective location - think homunculus
What is the homunculus? How is it organized with regards to body regions?
- “little man” that shows orientation of location in brain that controls certain part of body
- the larger the body part, the more neural control there is
What is the role of association cortices? What types of association cortices can be found in the brain?
- assist the primary cortices in complex movements
- unimodal (unidirectional) - just assist with motor signals
- heteromodal (bidirectional) - assist with motor and sensory
What are the major characteristic differences between the left and right hemispheres?
left - analytical thought, logic, reasoning, language
right - perceptual integration, imagination, insight, intuition, creativity, emotional drive
What is the function of the corpus callosum and where can it be found?
- connects right and left hemisphere (middle of brain)
- allows for bilateral integration
What other major commissural tracts can be found in the brain?
- anterior and posterior commissural tracts
Where is the insular cortex located? What function does it hold?
- beneath frontal and temporal lobes, folded deep within lateral sulcus
- integration of sensory input for visceral and autonomic function, somatic pain processing, olfactogustatory function, emotional regulation
Where is the limbic cortex located? What structures make up this area?
- center of brain- directly connects with insular lobe
- Parahippocampal gyrus, Medial orbitofrontal gyrus, Cingulate gyrus
- Uncus
- Fornix
- Temporal poles
- Hypothalamus
- Amygdala
- Hippocampus
What is the function of the limbic cortex?
- “primitive brain”
- homeostasis, smell, memory, and drive
What is the function of the thalamus and where is it found?
- relay station for sensory inputs, afferent info processing center, and refines motor outputs
- found in diencephalon
What is the function of the hypothalamus and where is it found?
- homeostasis hub, ventricular organ so no BBB
- diencephalon below thalamus, attaches to pituitary gland
What is the function of the epithalamus and where is it found?
- house pineal gland for melatonin production, habenular nuclei for emotional response to smell, and 3rd ventricle choroid plexus home for CSF production
- caudal to thalamus
What is the basic function of the basal ganglia? What structures are part of it?
- complex network that influence descending motor drive - movement initiation, execution, and refinement
- Caudate
- Putamen
- Globus Pallidus
- Substantia Nigra (midbrain)
- Subthalamic Nucleus
What is the basic function of the cerebellum?
- movement coordination, posture and balance, motor learning and control, muscle tone
What is the basic function of the brainstem?
- essential for survival and effective cognitive and motor functioning
