cerebrum Flashcards
What do the cerebral hemispheres develop from?
The telencephalon.
What is the largest part of the brain?
The cerebral hemispheres.
What are the three main components of each cerebral hemisphere?
- Gray matter (cortex) on the outer surface
- Internal gray matter (basal nuclei)
- A lateral ventricle
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Where is the cerebrum located?
In the anterior and middle cranial fossae.
Which part of the skull does the cerebrum occupy?
The entire concavity of the skull vault.
What are the two main subdivisions of the cerebrum?
- Diencephalon (central core)
- Telencephalon (cerebral hemispheres)
What does the diencephalon include?
The third ventricle and its boundaries.
What are the posterior and anterior extensions of the diencephalon?
Posterior → To the cerebral aqueduct
Anterior → To the interventricular foramina
How is the diencephalon positioned?
It is midline with symmetrical right and left halves.
Can nerve fibers cross boundaries in the diencephalon?
Yes, despite anatomical divisions.
What structures form the inferior surface of the diencephalon?
Hypothalamic structures.
List the structures on the inferior surface of the diencephalon from anterior to posterior.
- Optic chiasma and optic tracts
- Infundibulum with tuber cinereum
- Mammillary bodies
What covers the superior surface of the diencephalon?
The fornix.
What is the function of the fornix?
- It originates in the hippocampus
- arches over the thalamus
- joins the mammillary bodies.
What forms the roof of the third ventricle?
The ependymal layer and tela choroidea.
What projects into the third ventricle?
The choroid plexuses.
What bounds the lateral surface of the diencephalon?
The internal capsule (white matter).
What is the function of the internal capsule?
It contains fibers connecting the cerebral cortex to the brainstem and spinal cord.
What structures form the medial surface of the diencephalon?
Superior part: Thalamus
Inferior part: Hypothalamus
What separates the thalamus from the hypothalamus?
The hypothalamic sulcus.
What structure runs along the superior margin of the diencephalon?
The stria medullaris thalami.
What are the four major parts of the diencephalon?
- Thalamus
- Subthalamus
- Epithalamus
- Hypothalamus
What is the thalamus?
A large, ovoid gray matter mass.
What is the main function of the thalamus?
It is the main sensory relay station (except for the olfactory pathway).
What happens if the thalamus is damaged?
Major cerebral dysfunction occurs.
Where is the thalamus located?
On each side of the third ventricle.
What forms the posterior boundary of the interventricular foramen?
The anterior end of the thalamus.
What structure does the posterior end of the thalamus expand into?
The pulvinar.
What is the function of the pulvinar?
It overhangs the superior colliculus.
What is the lateral geniculate body?
A part of the visual pathway forming a small bump under the pulvinar.
What covers the superior surface of the thalamus?
The tela choroidea and fornix.
What is the inferior surface of the thalamus continuous with?
The midbrain tegmentum.
What does the medial surface of the thalamus form?
The lateral wall of the third ventricle.
How are the two thalami connected?
By the interthalamic adhesion.
What separates the lateral surface of the thalamus from the lentiform nucleus?
The internal capsule.
Where is the subthalamus located?
Inferior to the thalamus, between the thalamus and midbrain tegmentum.
What is the function of the subthalamus?
- It connects to the corpus striatum
- controls muscle activity.
What structures are found in the subthalamus?
- Subthalamic nucleus (biconvex lens shape)
- Red nuclei (cranial ends)
- Substantia nigra
- Ascending sensory tracts (medial, spinal, trigeminal lemnisci)
What structures make up the epithalamus?
- The habenular nuclei
- pineal gland.
What is the function of the habenular nuclei?
They integrate olfactory, visceral, and somatic afferent pathways.
Where does the habenular nucleus receive afferent fibers from?
The amygdala (via stria medullaris thalami).
What is the habenular commissure?
A structure where some fibers cross to the opposite habenular nucleus.
Where does the habenular nucleus send fibers?
- interpeduncular nucleus
- midbrain
- thalamus
- reticular formation.
What is the pineal gland?
A small, cone-shaped structure attached by the pineal stalk.
Does the pineal gland have a blood-brain barrier?
No.
What hormone does the pineal gland produce?
Melatonin.
What is the function of melatonin?
It regulates the circadian rhythm.
Which glands does the pineal gland inhibit?
- pituitary
- pancreas
- parathyroid
- adrenal glands.
მნემონიკი PPPA
Where is the hypothalamus located?
Below the thalamus, extending from the optic chiasma to the mammillary bodies.
What are the main functions of the hypothalamus?
- Controls the autonomic nervous system and endocrine system 2. Regulates temperature, thirst, hunger, emotions, and sexual behavior
What are the anatomical relations of the hypothalamus?
Anterior: Optic chiasma to lamina terminalis Posterior: Merges into midbrain tegmentum Superior: Related to thalamus Inferolateral: Related to subthalamic region
What structures of the hypothalamus can be seen from below?
- Optic chiasma 2. Tuber cinereum + infundibulum 3. Mammillary bodies
Where is the third ventricle located?
It is a slit-like space between the two thalami.
How does the third ventricle connect to the lateral ventricles?
Via the interventricular foramina (anteriorly).
How does the third ventricle connect to the fourth ventricle?
Via the cerebral aqueduct (posteriorly).
What forms the anterior wall of the third ventricle?
The lamina terminalis with the anterior commissure.
What structures are found in the posterior wall of the third ventricle?
The pineal recess, habenular commissure, and posterior commissure.
What forms the lateral walls of the third ventricle?
Superior part: Thalamus Inferior part: Hypothalamus (separated by the hypothalamic sulcus)
What forms the superior wall (roof) of the third ventricle?
The ependymal layer covered by tela choroidea and choroid plexuses.
What forms the inferior wall (floor) of the third ventricle?
- Optic chiasma 2. Tuber cinereum 3. Infundibulum 4. Mammillary bodies
What forms the largest and most developed part of the human brain?
The cerebral hemispheres form the largest and most developed part of the human brain.
What separates the cerebral hemispheres?
The longitudinal cerebral fissure separates the cerebral hemispheres.
What structure contains the longitudinal cerebral fissure?
The falx cerebri, a fold of dura mater, extends into the longitudinal cerebral fissure.
What supplies blood to the medial and superior parts of the frontal lobes?
The anterior cerebral arteries supply blood to the medial and superior parts of the frontal lobes.
What connects the two cerebral hemispheres?
The corpus callosum, a thick band of nerve fibers, connects the two cerebral hemispheres.
What separates the cerebral hemispheres from the cerebellum?
The tentorium cerebelli, another fold of dura mater, separates the cerebral hemispheres from the cerebellum.
What increases the surface area of the brain to allow more neurons to fit in the cranial cavity?
The folds and grooves on the surface of the brain increase surface area and allow more neurons to fit within the cranial cavity.
What are the raised areas on the surface of the brain called?
The raised areas on the surface of the brain are called gyri.
What are the grooves between the gyri called?
The grooves between the gyri are called sulci.
How are the cerebral hemispheres divided?
The cerebral hemispheres are divided into four lobes, each named after the overlying skull bone.
What are the four lobes of the cerebral hemispheres?
The four lobes of the cerebral hemispheres are the frontal lobe, parietal lobe, temporal lobe, and occipital lobe.
What is the function of the frontal lobe?
The frontal lobe is associated with movement, reasoning, and personality.
What is the function of the parietal lobe?
The parietal lobe is involved in sensory perception and spatial awareness.
What is the function of the temporal lobe?
The temporal lobe is concerned with hearing, memory, and language.
What is the function of the occipital lobe?
The occipital lobe is responsible for vision.
What is the central sulcus’s role in the brain?
The central sulcus separates the frontal lobe from the parietal lobe.
What is the function of the lateral sulcus (Sylvian fissure)?
The lateral sulcus divides the temporal lobe from the frontal and parietal lobes.
What does the parieto-occipital sulcus separate?
The parieto-occipital sulcus separates the parietal lobe from the occipital lobe.
Where is the calcarine sulcus located, and what is its function?
The calcarine sulcus is found in the occipital lobe and is important for processing vision.
What does the precentral gyrus of the frontal lobe do?
The precentral gyrus is the primary motor cortex, responsible for voluntary movements.
What functions do the superior, middle, and inferior frontal gyri serve?
The superior, middle, and inferior frontal gyri are involved in cognitive functions, decision-making, and voluntary movement control.
Where is Broca’s area located and what is its function?
Broca’s area is located in the inferior frontal gyrus of the dominant hemisphere and is crucial for speech production.
What is the postcentral gyrus responsible for?
The postcentral gyrus is the primary sensory cortex, responsible for processing touch, pain, and temperature sensations.
What do the superior and inferior parietal lobules do?
The superior and inferior parietal lobules are important for spatial orientation and sensory integration.
What does the superior temporal gyrus process?
The superior temporal gyrus contains the primary auditory cortex, which processes sound.
What do the middle and inferior temporal gyri do?
The middle and inferior temporal gyri are associated with memory and visual recognition.
What does Wernicke’s area do?
Wernicke’s area, located in the dominant hemisphere, is essential for language comprehension.
Where is the primary visual cortex located?
The primary visual cortex is located in the calcarine sulcus in the occipital lobe.
What do the visual association areas in the occipital lobe do?
The visual association areas in the occipital lobe help interpret and recognize visual information.
What structure connects the two cerebral hemispheres?
The corpus callosum connects the two cerebral hemispheres.
What is the cingulate gyrus involved in?
The cingulate gyrus is involved in emotions and behavior regulation.
What is the paracentral lobule responsible for?
The paracentral lobule is involved in motor and sensory functions of the lower limb.
What is the function of the precuneus?
The precuneus is involved in visuospatial processing, memory, and consciousness.
What is the function of the cuneus?
The cuneus is involved in basic visual processing.
What is the lingual gyrus involved in?
The lingual gyrus is associated with vision and recognizing words.
What does the parahippocampal gyrus do?
The parahippocampal gyrus is involved in memory encoding and retrieval.
What do the olfactory bulb and tract do?
The olfactory bulb and tract, located on the inferior surface of the frontal lobe, are responsible for smell perception.
What are the lateral ventricles, and what do they contain?
The lateral ventricles are two C-shaped cavities inside the cerebral hemispheres that contain cerebrospinal fluid (CSF).
How many parts does each lateral ventricle have, and what are they?
Each lateral ventricle has four parts: the anterior horn, body, posterior horn, and inferior horn.
What connects each lateral ventricle to the third ventricle?
The interventricular foramen (of Monro) connects each lateral ventricle to the third ventricle.
What are the basal nuclei and what do they control?
The basal nuclei, located deep in the brain, are groups of neurons involved in movement control.
What are the components of the corpus striatum?
The corpus striatum is subdivided by the internal capsule into the caudate nucleus and lentiform nucleus.
What is the function of the caudate nucleus?
The caudate nucleus helps with voluntary movement and learning.
What does the lentiform nucleus do?
The lentiform nucleus is involved in regulating movements.
What is the function of the amygdaloid nucleus?
The amygdaloid nucleus is part of the limbic system and is important for emotion processing.
What is the function of the claustrum?
The claustrum is a thin layer of gray matter whose function is not fully understood but may relate to sensory integration.
What is the role of white matter in the cerebral hemispheres?
White matter consists of myelinated nerve fibers that carry signals between brain regions.
What are the three types of fibers in the white matter?
The three types of fibers in white matter are commissural fibers, association fibers, and projection fibers.
What do commissural fibers do?
Commissural fibers connect the two hemispheres of the brain.
What is the largest commissural fiber bundle?
The corpus callosum is the largest commissural fiber bundle.
What are the anterior and posterior commissures?
The anterior and posterior commissures are smaller interhemispheric connections.
What does the fornix connect?
The fornix links the hippocampus to the hypothalamus and is crucial for memory formation.
What is the role of the habenular commissure?
The habenular commissure is part of the limbic system and is involved in emotional processing.
What do association fibers do?
Association fibers connect different areas within the same hemisphere, allowing them to work together.
What do projection fibers do?
Projection fibers connect the cortex to lower brain structures and the spinal cord, carrying motor commands down and sensory input up.
