Nervous System Anatomy

A bundle of nerve fibers (axons) located in the peripheral nervous system, extending throughout the body.

A group of nerve fibers (axons) within the central nervous system.

Regions within the central nervous system primarily composed of cell bodies and unmyelinated interneurons, involved in information processing.

Regions within the central nervous system mostly made up of myelinated axons, responsible for quick signal transmission.

A tough, flexible membrane that covers the brain and spinal cord, providing protection. It is the outermost layer of the meninges.

The cerebellum is a brain structure responsible for coordinating movements, motor control, and some cognitive functions like learning.

The cerebellum receives information from several senses (vision, hearing, touch, and body position) and integrates it with information about planned movements from the brain. This processed information helps fine-tune and coordinate movements.

The mesencephalon or midbrain is a crucial part of the brain stem, involved in sensory processing, movement control, and wakefulness.

The tectum is the dorsal part of the midbrain responsible for processing auditory and visual information. It plays a key role in orienting the body towards or away from stimuli.

The tegmentum is the ventral part of the midbrain containing important structures like the reticular formation and tracts that connect different brain regions.

The thalamus is a relay center for sensory information, filtering and passing it on to the cerebral cortex, the outer layer of the brain where higher-order processing occurs.

The hypothalamus is a small but important brain structure that regulates basic bodily functions like hunger, thirst, temperature, and hormone release, playing a vital role in maintaining homeostasis.

A group of nuclei in the thalamus that receive sensory signals from specific receptors, process the signals, and then transmit them to the relevant areas of the cerebral cortex. They also receive feedback from the cortex to control which sensory information is processed.

The main relay station for sensory information, receiving most neural input from the body and sending it to the cerebral cortex.

Located below the anterior thalamus, it plays a crucial role in regulating the body's internal environment, including functions like feeding, drinking, sleep, and body temperature.

A gland located beneath the hypothalamus that releases hormones to regulate various bodily functions.

The point where the optic nerves from each eye meet and some of the axons cross over to the opposite side of the brain.

A pair of rounded nuclei located at the inferior surface of the hypothalamus, involved in memory and other functions.

The outermost layer of the cerebral cortex, mainly composed of small, unmyelinated neurons, responsible for higher cognitive functions.

The intricate folds and furrows on the surface of the cerebral cortex. These convolutions increase the surface area of the cortex, allowing for greater processing power.

A brain region just rostral to M1, responsible for controlling M1 and involved in complex motor planning.

The most anterior part of the frontal lobe, crucial for executive functions like planning, reasoning, and judgment.

Impairment in initiating voluntary behavior, difficulty inhibiting inappropriate social behavior, and memory dysfunction due to damage to the prefrontal cortex.

The neocortex is the 6-layered layout of the cerebral cortex, responsible for higher cognitive functions.

This refers to the organization of neurons in the neocortex, forming vertical columns, each performing a specific function.

A three-layered brain region crucial for memory, especially spatial memory. It is located in the medial temporal lobe.

A collection of brain structures involved in emotion, motivation, and memory. Key components include the amygdala and hippocampus.

An almond-shaped brain structure in the temporal lobe, crucial for processing emotions, especially fear.

A set of brain structures deep within the cerebrum, involved in motor control, learning, and planning.

A view of the brain from the front, showing the face and the back of the head.

A view of the brain from the top, looking down on the brain.

A view of the brain from the side, showing the ears and the back of the head.

A view of the brain from the top, looking down on the brain.

Part of the nervous system that controls involuntary bodily functions.

A set of 12 nerves that connect the brain to the head and neck.

A fluid-filled space between the arachnoid membrane and pia mater, containing cerebrospinal fluid.

A network of blood vessels that supplies the brain with nutrients and oxygen.

The part of the spinal cord that carries sensory information to the brain.

The myelencephalon (medulla) and metencephalon (pons and cerebellum) together make up the hindbrain.

The telencephalon (cerebral hemispheres) and diencephalon (thalamus and hypothalamus) form the forebrain.

The reticular formation, a network of neurons involved in arousal and sleep-wake cycles, is present in the mesencephalon (midbrain), myelencephalon (medulla), and metencephalon (pons), but not the diencephalon.

The cerebellum is part of the metencephalon, which also includes the pons.

The tectum is the dorsal surface of the mesencephalon (midbrain).

The inferior and superior colliculi, involved in auditory and visual processing, are located in the tectum of the midbrain.

The substantia nigra, a brain region associated with motor control, is located ventral to the periaqueductal gray, a region involved in pain processing.

The reticular formation, a part of which is found in the mesencephalon, is located dorsal to the red nucleus, a region involved in motor control.

The two thalamic lobes are on each side of the third ventricle, a fluid-filled space within the brain.

The hypothalamus, responsible for regulating many bodily functions, is located just inferior to the anterior thalamus.

The anterior-posterior axis refers to the direction from the front to the back of the brain. The inferior-superior axis refers to the direction from the bottom to the top of the brain. The lateral-medial axis refers to the direction from the side to the middle of the brain.

The lateral sulcus, also known as the Sylvian fissure, separates the temporal lobe from the frontal and parietal lobes. The central sulcus divides the frontal lobe from the parietal lobe, with the precentral gyrus located in front of it and the postcentral gyrus behind it.

The sympathetic nervous system, part of the autonomic nervous system, is responsible for the 'fight-or-flight' response. It prepares the body for stressful situations by increasing heart rate, blood pressure, and blood flow to muscles. In the case of the genitalia and gut, the sympathetic system has an inhibitory effect, slowing down blood flow.

Brain plasticity refers to the brain's ability to change and adapt its structure and function over time in response to experiences. This includes changes in the connections between neurons, the ability to learn new skills, and the ability to recover from brain injury.

A coronal section divides the brain into front (anterior) and back (posterior) portions. Therefore, nucleus A is more dorsal and lateral relative to nucleus B in this picture.

The thalamus is a central relay station for sensory information, receiving input from the body and sending it to the appropriate areas of the cerebral cortex. This filtering and relaying of information allows the brain to process sensory information efficiently and selectively.

The premotor cortex is a key area for planning and coordinating complex movements. It is located just in front of the primary motor cortex (M1). It receives input from various brain areas, including the prefrontal cortex, and sends signals to M1 to initiate and control movements.

The prefrontal cortex, the most anterior part of the frontal lobe, is responsible for higher-level cognitive functions such as planning, decision-making, working memory, and complex social behaviors. It plays a crucial role in our ability to inhibit impulsive behaviors and to manage emotions.

The hippocampus, located in the medial temporal lobe, is essential for memory, particularly spatial memory. It plays a crucial role in forming new memories and retrieving existing ones.

The amygdala, located in the temporal lobe, is a key structure for processing emotions, especially fear and anxiety. It receives sensory input and quickly assesses the potential threat level of a situation, triggering appropriate responses.

The primary auditory cortex is located on the superior temporal gyrus, a prominent brain region involved in processing sound information.

The insular cortex is located deep within the brain, hidden from view when looking at a whole brain from the side.

The medial-lateral axis of the brain arranges structures from the middle (medial) to the outer side (lateral). The correct order is thalamus, third ventricle, hippocampus, and then the cerebral cortex.

The amygdala, responsible for processing emotions, especially fear, is located within the medial temporal lobe.

The cingulate cortex is situated on the cingulate gyrus, positioned dorsal (towards the top) to the corpus callosum, the bridge connecting the two brain hemispheres.

The fornix, a crucial pathway for memory and learning, connects the septum and mammillary bodies with the amygdala and hippocampus.

The globus pallidus, a key part of the basal ganglia, is situated between the thalamus and the striatum.

Broca's area, crucial for language production, is located on the inferior frontal gyrus.

The hippocampus plays a vital role in memory formation and retrieval, particularly spatial memory, working like a file cabinet for experiences and locations.

The limbic system acts as the brain's emotional center, composed of structures like the amygdala and hippocampus. It plays a crucial role in emotions, motivations, and memory.