What does the interhemispheric fissure separate?
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The two hemispheres of the brain.
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What does the interhemispheric fissure separate?
The two hemispheres of the brain.
What is the anterior lobe of the pituitary gland also known as?
Adenohypophysis.
From where does the pituitary gland extend?
From the ventral surface of the hypothalamus via the pituitary stalk or infundibulum.
What is the function of the fornix?
It connects the hippocampus to other brain structures.
What is the first step in the 3-D dissection procedure?
Remove the caudal right neocortex and open up the interhemispheric fissure until the corpus callosum is visible.
What is the role of the hypothalamus in the endocrine system?
It controls the endocrine system directly and indirectly through the pituitary gland.
What is the primary function of the mesencephalon?
Control of eye movement and relay in the auditory pathway.
What does the myelencephalon become?
The medulla oblongata.
Where is the middle cerebral artery located in relation to the internal carotid artery?
It comes off the ICA in humans.
What substance covers the axon and contributes to the color of white matter?
Myelin.
How does the brain receive its blood supply?
Directly from the heart via the right and left internal carotid arteries and the vertebral arteries.
What is the purpose of following the optic tract during the dissection?
To locate the lateral geniculate nucleus of the thalamus.
Which arteries arise from the circle of Willis?
Anterior, anterior communicating, middle, posterior, and posterior communicating cerebral arteries.
Which nuclei make up the basal ganglia?
Caudate, putamen, globus pallidus, and subthalamic nuclei.
Where is the infundibular stalk located?
On the ventral side of the brain, midway between the rostral and caudal ends.
What sulcus marks the boundary of the frontal lobe?
The superior frontal sulcus.
What does the central sulcus separate in the human brain?
The frontal and parietal lobes.
What are the main structures associated with the basal ganglia?
Caudate, Hippocampus, Thalamus, and Corpus Callosum.
What type of specimens are used for dissection in this week?
Preserved sheep brains with the dura removed.
What two roles does the limbic system play?
Emotions important for survival and processes involved in memory.
What lies beneath the cerebral cortex?
White matter.
What is the shape of the thalamus?
Football shape.
What does the optic chiasm do?
It is where the optic nerves cross, allowing visual information from both eyes to be processed.
What vital functions does the medulla regulate?
Breathing and heart rate.
What are the sensory and motor decussations?
Crossing points in the medulla.
What structure is formed by the basilar and carotid arteries?
The circle of Willis.
How can the anterior commissure be located?
By looking between the two caudate nuclei and teasing away to see the white matter tracts in the midline.
Why does the brain need a constant blood supply?
Because it has very little storage for oxygen or glucose.
What is the function of the archicortex?
Important for learning and memory.
What is the neocortex responsible for?
Higher cognitive functions and accounts for 80-90% of the cortex in humans.
What are the four major lobes of the human brain?
Frontal lobe, parietal lobe, temporal lobe, occipital lobe.
How does the temporal lobe in sheep compare to that in humans?
The temporal lobe in sheep is poorly developed compared to the human brain.
What is the posterior lobe of the pituitary gland also known as?
Neurohypophysis.
What is the primary focus of Week 2's learning objectives?
To learn about the blood supply to the brain.
Which nuclei are found in the pons?
Noradenergic locus coeruleus, serotonergic nucleus raphe, and the reticular formation.
Why is the limbic system considered one of the oldest systems in the CNS?
Due to its importance for the survival of the species.
What hormones are secreted by the posterior pituitary?
Arginine vasopressin (AVP, also known as ADH) and oxytocin.
What structures does the metencephalon develop into?
The pons and cerebellum.
What can be identified within the lateral ventricle?
The choroid plexus.
What artery is located beneath the optic chiasm?
Anterior communicating artery.
What arteries lie in the midline on the ventral surface of the frontal lobe?
Anterior cerebral arteries.
What are the bumps and grooves on the cerebral hemispheres called?
Gyri, sulci, and fissures.
Which thalamic nucleus is involved in visual processing?
Lateral geniculate.
What does the medial dorsal nucleus of the thalamus project to?
Olfactory inputs to the orbitofrontal cortex.
What role does the hypothalamus play in the body?
It coordinates the interaction between the nervous and endocrine systems.
What structures comprise the limbic system?
Both telencephalic and diencephalic structures.
What role does the amygdala play?
It is involved in emotional behaviors and is connected to the olfactory and limbic systems.
What structure joins the two cerebellar hemispheres?
The median vermis.
What distinctive feature is found in the cerebellar cortex?
Laminations with parallel fissures and sulci interposed between thin folia.
What is the area caudal to the central sulcus in humans?
The parietal lobe.
What are the distinct arrangements found within some cortical areas of the neocortex?
Distinct functional columns.
What structures are contained within the metencephalon?
The pons and the cerebellum.
What part of the brain is involved in the reward circuitry and is part of the limbic system?
Nucleus accumbens.
What should you save for use during week three?
Isolated brainstem and cerebellum.
What gives the cerebral cortex its grayish color?
Neurons, which are termed gray matter.
What structure covers the diencephalon?
Cerebral hemispheres.
What is the role of the pineal body?
It regulates sleep-wake cycles through melatonin production.
How many cranial nerve nuclei are located in the medulla?
Five of the twelve cranial nerve nuclei.
What structure is anterior to the hippocampus in the lateral ventricle?
The caudate.
What is the fornix and where does it lead?
The fornix is a structure that travels downward and terminates in the mammillary bodies of the hypothalamus.
Which thalamic nucleus processes auditory inputs?
Medial geniculate.
What is the role of the basal ganglia?
To participate in the control of motor activity and motor planning.
What is the hypophyseal portal system?
Capillary beds that surround the pituitary gland.
What are the superior and inferior colliculi collectively called?
The tectum of the midbrain.
Which structures should be identified on the inferior surface of the brain?
Olfactory bulb, optic chiasm, optic tract, hypothalamus, cerebral peduncle, pons, medulla oblongata, pyramidal tract, trapezoid body, and spinal cord.
How many layers are there in the laminar organization of the neocortex?
Six layers.
What is the origin of the anterior lobe of the pituitary gland?
Ectodermal origin.
What is the function of the Sylvian or lateral fissure?
It separates the temporal lobe from the frontal and parietal lobes.
What is the origin of the posterior lobe of the pituitary gland?
Neuroectodermal origin.
What anatomical structures are studied in relation to the cerebral hemispheres?
The structure and function of the cerebral hemispheres and brainstem.
What are the diencephalic structures mentioned?
Mammillary bodies, hypothalamus, and anterior nucleus of the thalamus.
What is the role of the cerebellum?
To modulate the rate, force, and range of muscular contractions for smooth movement and posture.
How is the cerebellum connected to other brain structures?
Via three pairs of massive fiber bundles known as cerebellar peduncles.
What artery connects to the internal carotid artery (ICA)?
Posterior communicating artery.
How does the anterior pituitary receive regulating hormones?
Through the hypothalamic-pituitary portal system.
What are the two categories of nuclei in the thalamus?
Relay nuclei and association nuclei.
What do the right and left vertebral arteries form?
The basilar artery.
What should be done after removing the entire cortex?
You should yield the brainstem, thalamus, hippocampus, and cerebellum preparation.
What is the lentiform nucleus composed of?
Putamen and globus pallidus.
What are the inputs to the basal ganglia primarily from?
The cerebral cortex, mainly the sensory and motor areas.
Which telencephalic structures are part of the limbic system?
Cingulate gyrus, parahippocampal gyrus, hippocampus, fornix, amygdala, and olfactory bulb.
What is the primary function of the hippocampus?
It plays an integral role in attention, learning, and memory.
What is the pyriform lobe?
The area below the rhinal sulcus, often pear-shaped.
Why is blood important to the brain?
Because it supplies oxygen and glucose.
What is the primary function of the pons?
To serve as a relay for telencephalic structures and the cerebellum.
What artery lies on the base of the pons?
Basilar artery.
What arteries come off the basilar artery at the rostral end of the pons?
Anterior (superior) cerebellar arteries.
What type of neurons produce hormones in the posterior pituitary?
Magnocellular neurons.
What is the role of the pons?
Contains relay nuclei that relay information from the cerebral hemispheres to the cerebellum.
What does the myelencephalon become?
The medulla oblongata.
What is the function of the medulla oblongata?
It is the rostral extension of the spinal cord and contains cranial nerve nuclei and areas of fiber crossing.
What does the diencephalon develop into?
The thalamus and hypothalamus.
What is the function of the thalamus?
It serves as a major relay station between the telencephalon and other brain regions.
What structures comprise the paleocortex?
Olfactory cortex, pyriform lobe, and parts of the parahippocampal gyrus.
What does the sylvian fissure delineate in the sheep brain?
The primary motor cortex in the frontal lobe and the primary sensory cortex in the parietal lobe.
What separates the two cerebral hemispheres?
The medial longitudinal fissure (interhemispheric fissure).
What is located between the cerebellum and the brainstem?
The 4th ventricle.
What is the structure that supplies blood to the brain?
An extremely complex capillary system.
What is the anatomical location of the pons in relation to the medulla?
The pons lies rostral to the medulla.
Where do you start examining the major blood vessels in the sheep brain?
At the caudal section of the brainstem at the junction of the medulla and the pons.
How should excess specimen materials be disposed of?
In biohazard disposal boxes.
What are the superior and inferior colliculi involved in?
They are involved in visual and auditory processing.
What structure lies below the white matter in the dissection?
The lateral ventricle.
What is the function of an axon?
To communicate with other neurons.
What is the weight of the human brain?
3 lbs (1400g).
What are the three major vesicles formed during the development of the nervous system?
Prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain).
What does the telencephalon develop into?
The cerebral hemispheres (cerebrum).
What is the difference between a sulcus and a fissure?
A sulcus is a small groove, while a fissure is a large groove.
What is the significance of the circle of Willis?
It provides blood to the cerebral hemispheres.
What separates the frontal and parietal lobes?
The central sulcus.
What should you do with the sheep specimen in Carosafe® solution?
Place it in a plastic container with a paper towel at the bottom to keep it moist.
What is the thickness and structure of the cerebral cortex referred to in the dissection?
The cerebral cortex is 6 layers of cells, known as isocortex or neocortex.
What are the corona radiata?
They are the myelinated fibers of the afferents going to the cortex and the efferents going from the cortex.
What percentage of the body's oxygen requirements does the brain utilize?
20%.
What is the primary function of the thalamus?
Processes most of the information reaching the cerebral cortex from the rest of the CNS.
What is the function of the hypothalamus?
It regulates homeostasis and controls the endocrine system.
Which thalamic nucleus is responsible for touch sensation?
Ventral posterior lateral nucleus.
What structures are included in the limbic system?
Hippocampus, amygdala, cingulate gyrus, fornix, mammillary bodies, and olfactory bulb.
What is the largest part of the cerebral hemispheres?
The cerebral cortex.
What are the four lobes of the neocortex?
Frontal, parietal, temporal, and occipital lobes.
What arteries make up the Circle of Willis?
Posterior cerebral, posterior communicating, middle cerebral, anterior cerebral, and anterior communicating arteries.
What are the two lobes of the pituitary gland?
Anterior (adenohypophysis) and posterior (neurohypophysis) lobes.
What is the primary motor cortex's location relative to the crucial sulcus?
Anterior to the crucial sulcus.
What structure is revealed by pulling back the cerebellum?
The dorsal surface of the brain stem, including the corpora quadrigemina.
