historical perspectives and neuroanatomy

monism

one underlying reality: either body or mind

materialism

form of monism, the world consists of only matter and energy, and the mind is part of it

dualism

body and mind exist, the body is physical and the mind is not

interactionism

the interaction of the material body and immaterial mind takes place in the brain

form of dualism

parallelism

both mind and body exist, but the two do not interact

form of dualism

hippocrates

placed the functions of the mind firmly in the brain

rene descartes

the body works like a machine, it follows the law of physics

the mind lacks extension and motion, it does not follow the laws of physics

mind interacts with the body at the pineal gland

phrenology

founded by franz joseph gall

assumes that mental functions are localized in certain brain areas and that mental functioning is related to the size and integrity of the brain

the moral and intellectual character of a person can be determined by studying the bumps and indentations on their skull

phineas p gage

rod went through his skull and damaged the prefrontal cortex, effecting his ability to make rational decisions and process emotional information, causing extreme personality change

broca’s area

area in the frontal lobe of the left hemisphere of the brain that contributes to speech production

when damaged, the person has difficulty speaking but has relatively good language comprehension

wenicke’s area

area in the temporal lobe of the left hemisphere of the brain that contributes to understanding language and producing intelligible speech

when damaged, the person can speak easily, but speech is meaningless and language comprehension is poor

negative signs

clinical symptoms that result from the failure of a system to produce a function

inabilities to move, feel, see, and hear

positive signs

symptoms in which an abnormal symptom occurs in place of or in addition to normal functioning

sensations of pins and needles or tingling, excess unwanted movements, visual or auditory hallucinations

locked in syndrome

also known as pseudo-coma, patient is aware but cannot move or communicate verbally due to complete paralysis

neurons

main function is to transmit information in the form of electrical signaling, most times over long distances

soma

metabolic center, principal activity is to participate in the expression of genetic information

synthesis of proteins needed for growth and maintenance of cell

enzyme

catalyst, a substance that controls a specific chemical reaction

takes part in the reaction, but it is not affected by it

channel proteins

provide channels for the passage of substances from one side of the membrane to the other

receptor proteins

recognize and bind to neurotransmitters or other chemicals

pump proteins

exchange one type of substance for another, help maintain resting membrane potential

dendrites

receive input from other neurons through synapses formed with the synaptic terminal of the axons from presynaptic neurons

generate and integrate postsynaptic potentials and intracellular signal cascades

axon

single projection that can vary in length, grows out of hillock to connect to postsynaptic neurons

myelin sheath

insulating substance consisting of lipids and proteins, increases resistance of membrane and speeds up the conductance of neuronal currents

schwann cells

cells in the peripheral nervous system that form the myelin sheat

oligodendrocytes

cells in the central nervous system that form the myelin sheath

nodes of ranvier

allow for the exchange of ions between the axon and the extracellular space

microglia

mediates immune response, ingests bacteria, dead cells, or protein plaques

activated when large amounts of debris are produced by the brain

astrocytes

second most common type of glia, they surround the neuron to supplying vessels

involved in regulation of blood supply through release of vasoactive substances

removal and metabolism of excess neurotransmitter, supply of nutrients to the neurons

peripheral nervous system (PNS)

detects environmental information inside and outside the body

nerves

bundles of axons in the peripheral nervous system

ganglia

clusters of cell bodies in the peripheral nervous system

autonomic nervous system

motor system that regulates internal environment

parasympathetic vs sympathetic

somatic nervous system

includes both sensory and motor (skeletal muscles)

central nervous system (CNS)

recognizes and analyzes information, makes decisions, and transmits decisions to glands, organs, and muscles for execution

proximal

structures that are close to one another

distal

structures that are far from one another

afferent

any movement toward a brain structure

efferent

any movement away from a brain structure

horizontal

shows structures viewed from above

sagittal

divides structures into right and left parts (see from the side)

coronal

shows view from the front

brainstem

consists of the medulla, pons, and midbrain

connects the spinal cord to the forebrain, regulation of vital body functions

medulla oblongata

controls autonomic basic life functions (respiration, heart rate, vomiting, salivation)

reticular formation

begins in the medulla, extends to other areas of the brain and is involved in arousal (maintains consciousness)

pons

a bridge connecting the medulla with the midbrain

sensory fibers from the cortex to cerebellum, and fibers that relay information on sleep, arousal and dreaming pass through it

origin of important modulatory (serotonin, noradrenaline) pathways

raphe

located in central part of the medulla, pons, and midbrain

neurons contain serotonin

locus coeruleus

located dorsal wall of the upper parts of the pons

neurons contain noradrenaline

cerebellum

contains 80% of the neurons of the human brain and plays a central role in motor control, development and coordination movement, and posture

midbrain

sits between the forebrain and the hindbrain

source of dopamine projections and relay station for sensory and motor signals

tectum

“roof”

part of the midbrain that relays visual and auditory information and controls simple reflexes, eye and ear orientation movements

contains the superior and inferior colliculi

superior colliculi

relays visual information

inferior colliculi

relays auditory information

tegmentum

“floor covering”

part of the midbrain that contains the substantia nigra, VTA, PAG, red nucleus, and reticular formation

substantia nigra

nucleus of dopaminergic neurons projecting to the caudate nucleus and putamen in the basal ganglia; integrate voluntary movements

ventral tegmental area (VTA)

contains dopaminergic neurons projecting to the nucleus accumbens (NAcc)

part of the reward circuit, implicated in mental disorders

red nucleus

part of the tegmentum that controls basic body movements (limbs)

reticular formation

controls arousal and consciousness, located in both the pons and tegmentum

periaqueductal gray (PAG)

separates the tegmentum from the tectum

involved in the perception of pain and sexual behavior

diencephalon

consists hypothalamus, epithalamus, and thalamus

epithalamus

habenula (olfactory functions) and pineal gland (produces melatonin)

thalamus

major relay station for sensory information

medial geniculate nucleus (MGN)

part of the thalamus that relays auditory information

lateral geniculate nucleus (LGN)

part of the thalamus that relays visual information

hypothalamus

detects need states (hunger, thirst), controls the autonomic nervous system, and control pituitary hormone production and release, motivated behavior

superchiasmatic nucleus

part of the hypothalamus that is also involved in the control of biological rhythms

telencephalon

consists of the basal ganglia, limbic system, and cerebral cortex

basal ganglia

have widespread connections to the cortex and forebrain and are involved in the initiation of voluntary movements, maintaining muscle tone and posture

corpus striatum

part of the basal ganglia that contains the caudate nucleus and the putamen

important for muscle memory and habit formation

limbic system

governs emotions, (anger, happiness, fear) and is involved in the storage and retrieval of memories

group of structures surrounding the brain stem

cingulate cortex

involved in integrating sensory, motor, visceral, motivational, and emotional information

part of the limbic system

anterior cingulate

part of the cingulate cortex that is involved in decisions related to empathy, fairness/unfairness, and the social context of behavior

posterior cingulate

part of the cingulate cortex required for monitoring performance and keeping motivated during learning, particularly when problems are challenging

reward circuit

VTA connects to the nucleus accumbens, amygdala, septum, prefrontal cortex via the medial forebrain bundle (MFB)

cerebral cortex

convoluted outer layer of the forebrain, processes sensory information, controls thinking, decision making, stores and retrieves memory, and initiates motor responses

occipital lobe

lobe responsible for analysis of visual information

parietal lobe

lobe where the anterior portion (somatosensory cortex) analyzes sensory information (pain, pressure, and body position) while the posterior portion is involved in spatial perception

temporal lobe

lobe that includes the primary auditory cortex, a visual area, and language centers

frontal lobe

lobe that is the motor cortex and involved in muscle movement, area for programming and sequencing of motor movements for speech production

primary areas

part of the telencephalon that receive projections from the major sensory systems or send motor projections to the muscles (motor cortex sends projections to brainstem and spinal cord motor systems)

secondary areas

part of the telencephalon that is adjacent to primary areas and involved in elaborating information received from primary areas, or sending commands to, for example, motor areas

tertiary areas

area of the telencephalon also known as the association cortex, can receive projections from them and send information to them