Week 2

Para

around

Parasympathetic nerves

travel a longer distance before terminating in parasympathetic ganglia

Parasympathetic ganglia

clusters of neurons that are usually located close to the organs they serve

Norepinephrine

received from sympathetic nerves

Acetylcholine

received from parasympathetic nerves

Spinal cord

funnels sensory information from the body up to the brain and conveys the brain's motor commands out to the body

Sagittal plane

the plane that divides the body or brain into right and left portions

Coronal plane

frontal plane, transverse plane; plane that divides the body or brain into front and back parts

Horizontal plane

the plane that divides the body or brain into upper and lower parts

Medial

toward the middle

Lateral

toward one side

Ipsilateral

pertaining to a location on the same side of the body

Contralateral

pertaining to a location on the opposite side of the body

Superior

above

Inferior

below

Basal

toward the base or toward the bottom of a structure

Anterior

rostral; toward the head end of an organism

Posterior

caudal; toward the tail end of an organism

Proximal

near the trunk or center of an organism

Distal

toward the periphery of an organism or toward the end of a limb

Afferent

carrying action potentials toward the brain or toward from one region of interest from another region of interest

Efferent

carrying action potentials away from the brain or away from one region of interest toward another region of interest

Dorsal

toward the back of the body or the top of the brain

Ventral

toward the belly or front of the body or the bottom of the brain

Gray matter

areas of the brain that are dominated by cell bodies and are devoid of myelin, mostly receives and processes information

White matter

layer of tissue consisting mostly of myelin-sheathed axons that lies underneath the gray matter of the cortex, mostly transmits information

Cerebral hemisphere

one of the two halves (right or left) of the forebrain

Cerebral cortex

also called cortex, the outer covering of the cerebral hemispheres which consists largely of nerve cell bodies and their branches

Gyrus

a ridged or raised portion of the cortical surface

Sulcus

a crevice or valley of the cortical surface

Frontal lobe

the most anterior portion of the cerebral cortex

Parietal lobe

the large region of cortex lying between the frontal and occipital lobes in each cerebral hemisphere

Temporal lobe

the large lateral region of cortex in each cerebral hemisphere, it is continuous with the parietal lobe posteriorly and separated from the frontal lobe by the Sylvian fissure; crucial for audition and memory formation

Occipital lobe

a large region of cortex that covers much of the posterior part of each cerebral hemisphere; crucial for vision

Sylvian fissure

lateral sulcus, a deep fissure that demarcates the temporal lobe

Central sulcus

a fissure that divides the frontal lobe from the parietal lobe

Corpus callosum

the main band of axons that connects the two cerebral hemispheres

Postcentral gyrus

the strip of parietal cortex, just posterior to (behind) the central sulcus, that receives somatosensory information from the entire body (primary somatosensory cortex)

Precentral gyrus

the strip of frontal cortex, just anterior to the central sulcus that is crucial for motor control (primary motor cortex)

Somatotopic organization

precise mapping of the various parts of the contralateral side of the body

Neural tube

an embryonic structure with subdivisions that correspond to the future forebrain, midbrain, and hindbrain

Forebrain

the frontal division the neural tube, containing the cerebral hemispheres, the thalamus, and the hypothalamus

Midbrain

the middle division of the brain

Hindbrain

the rear division of the brain, which in the mature vertebrate contains the cerebellum, pons, and medulla

Telencephalon

the anterior part of the fetal forebrain, which will become the cerebral hemispheres in the adult brain

Diencephalon

the posterior part of the fetal forebrain which will become the thalamus and hypothalamus in the adult brain

Brainstem

the region of the brain that consists of the midbrain, the pons, and the medulla

Nucleus

a collection of neuronal cell bodies within the central nervous system (caudate nucleus)

Tract

a bundle of axons found within the central nervous system

Ganglia

collections of neurons outside the CNS

Nerves

bundles of axons outside the CNS

Bilateral symmetry

property of vertebrates that mirrors the left and right side of the body

Contralateral

each side of the brain controls the opposite side of the body

6

layers made up by cortical neurons

Layer I

has few cell bodies

Layers V and VI

many neurons with large cell bodies

Pyramidal cell

A type of large nerve cell that has a roughly pyramid-shaped cell body and is found in the cerebral cortex, usually in layer III or V

Cortical column

One of the vertical columns that constitute the basic organization of the cerebral cortex; extend through the entire thickness of the cortex from the white matter to the surface

Basal ganglia

A group of forebrain nuclei, including the caudate nucleus, globus pallidus, and putamen, found deep within the cerebral hemispheres; control of movement

Limbic system

A loosely defined, widespread group of brain nuclei that innervate each other and form a network; involved in emotion and learning

Amygdala

A group of nuclei in the medial anterior part of the temporal lobe; emotional regulation and perception of odor

Hippocampus

A medial temporal lobe structure that is important for learning and memory

Fornix

A fiber tract that extends from the hippocampus to the mammillary body

Cingulate gyrus

A strip of cortex, found in the frontal and parietal midline, that is part of the limbic system and is implicated in many cognitive functions

Olfactory bulb

An anterior projection of the brain that terminates in the upper nasal passages and provides the primary inputs for the sense of smell

Thalamus

Paired structures to either side of the third ventricle that direct the flow of sensory information to and from the cortex; directs information to the appropriate regions of the cortex

Hypothalamus

Part of the diencephalon, lying ventral to the thalamus; help govern motivated behaviours like sex and aggression, and regulate the hormonal systems of the body; hunger, thirst, temperature regulation, etc.

Tectum

The dorsal portion of the midbrain, consisting of the inferior and superior colliculi; sensory processing

Superior colliculi

Paired gray matter structures of the dorsal midbrain that process visual information

Inferior colliculi

Paired gray matter structures of the dorsal midbrain that process auditory information

Tegmentum

The main body of the midbrain, containing the substantia nigra, periaqueductal gray, part of the reticular formation, and multiple fiber tracts.

Substantia nigra

A brainstem structure that innervates the basal ganglia and is a major source of dopaminergic projections

Parkinson's disease

caused by loss of neurons in the substantia nigra

Periaqueductal gray

A midbrain region involved in pain perception

Reticular formation

An extensive region of the brainstem, extending from the medulla through the thalamus, that is involved in sleep and arousal

Cerebellum

A structure located at the back of the brain, dorsal to the pons, that is involved in the central regulation of movement and in some forms of learning

Pons

the portion of the brainstem that connects the midbrain to the medulla; contains many nerve fibers and important motor control and sensory nuclei, point of origin for several cranial nerves

Medulla

the posterior part of the hindbrain, continuous with the spinal cord; conveys major motor and sensory fibers to and from the body and drives essential processes like respiration and heart rate

Connectome

the network map that completely describes the functional connections within and between brain regions based on huge volumes of human and nonhuman animal neuroanatomical data