NEU 200 Midterm Review

Ascending reticular activating system

Ascending reticular activating system

consists of the incoming (afferent) nerve fibers running through the reticular formation that influence physiological arousal and consciousness

Anterior

The frontal portion of the brain (towards the front of the body)

Posterior

The back portion of the brain (towards the back of the body)

Medulla

The structure where the brain and spinal cord connect - it's an important conduit for signals to and from the CNS and PNS, and controls processes such as heartbeat, breathing, and blood pressure

Lateral

In this view of the brain, you will be able to see the lateral sulcus (the point where you know the temporal lobe covers the insula) and the tempoparietal junction. Basically looking at the 'outer' part of the brain.

Pons

A brain structure that regulates sleep-wake cycles and pain signals, and it also works with other structures such as the cerebellum and other parts of the brain stem. It also contains key junctions for four of the twelve cranial nerves.

Dorsal

The superior portion of the brain

Medial View

In this view, you will be able to see the amygdala and the striatum, as well as the corpus callosum and other internal midbrain structures. This is basically the 'inner' view of the brain.

Ventral

The inferior portion of the brain

Cerebellum

Part of your brain that is involved in coordinating voluntary movements as well as fine-tuning them. Implicated in fine motor control, and located in the ventral posterior area attached to the brain (little brain)

Midbrain

Functions as a relay system and vital connection point between the forebrain and the hindbrain. It also functions in motor movement such as eye movement, as well as audio/visual processing. As the name suggests, it's in the middle of the brain.

Superior Colliculus/Optic Tectum

Located in the midbrain; involved in incorporating environmental stimuli to coordinate eye and head shifts (in nonhuman animals, it's referred to as the optic tectum)

Inferior Colliculus

Part of the midbrain; main channel for auditory signals in the body. Mainly focuses on signal integration, frequency recognition, and pitch discrimination

Thalamus

The 'Grand Central Terminal' of the brain, it relays motor and sensory signals to the cerebral cortex.

Hypothalamus

Homeostasis icon; functions to keep the body in this stable state and does this by coordinating release of hormones or influencing the autonomic nervous system.

Pituitary

Basically the 'master gland' of the body, controls all other glands in the body to release hormones that regulate bodily functions.

Cerebral cortex

Outer layer of the brain's surface; carries out the brain's essential functions, such as memory, thinking, learning, reasoning, emotions, sensory functions, and consciousness.

Hippocampus

A neural center located in the limbic system that helps process explicit memories for storage into long-term memory in the cortex

Basal Ganglia

a set of subcortical structures that directs intentional movements

Gyrus

A ridged or raised portion of a convoluted brain surface.

Sulcus

a groove in the brain surface

Occipital lobe

A region of the cerebral cortex that processes visual information; located at the back of the cerebral cortex

Temporal lobe

An area on each hemisphere of the cerebral cortex near the temples that is the primary receiving area for auditory information

Parietal lobe

portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for touch and body position

Frontal lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement; at the front of the cerebral cortex

6 layers of cortex

1.Molecular Layer-input from other cortical areas

2.External Granular- input from other areas of the cortex (lateral)

3.External Pyramidal- output to other areas of the cortex

4.Internal Granular- input from the thalamus

5.Internal Pyramidal- output to subcortical structures and the spinal cord

6.Multiform Layer-feeds back to the thalamus

Cortical column

Anatomic organization that represents a functional unit six cortical layers deep and approximately 0.5 mm square, perpendicular to the cortical surface.

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Terminal

The end of the axon of a neuron (axon terminal)

Dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

Presynaptic side of synapse

usually an axon terminal. The terminal typically contains dozens of small membrane-enclosed spheres, each about 50 nm in diameter, called synaptic vesicles, which contain neurotransmitters

Postsynaptic side of synapse

May be a dendrite or the soma of another neuron. Neurotransmitter receptors here are specialized proteins that bind neurotransmitter molecules and can cause an EPSP or IPSP, depending on the ion that is brought in.

axon hillock

The conical region of a neuron's axon where it joins the cell body; the region where the action potential is generated.

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

myelin sheath

A layer of fatty tissue (from specialized glial cells) segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next. CNS: Oligos; PNS: Schwann cells

Nodes of Ranvier

Gaps in the myelin sheath to which voltage-gated sodium channels are confined; allows for the action potential to be replenished as it moves down the axon

glial cell

nervous system cell that provides physical and metabolic support to neurons, including neuronal insulation and communication, and nutrient and waste transport

Oligodendrocyte

A type of glial cell that forms myelin sheaths in the central nervous system

Astrocytes

Provide structural and metabolic support for neurons; forms the blood brain barrier

Microglia

phagocytic cells that ingest and break down waste products and pathogens in the CNS; eat damaged cells and bacteria, act as the brain's immune system

radial glia

guide the migration of neurons and the growth of their axons and dendrites during embryonic development

EPSP

Excitatory postsynaptic potential; a slight depolarization of a postsynaptic cell, bringing the membrane potential of that cell closer to the threshold for an action potential.

IPSP

Inhibitory postsynaptic potential; a slight hyperpolarization of the postysynaptic cell, moving the membrane potential of that cell further from threshold.

Action potential

the change in electrical potential associated with the passage of a nerve impulse along the membrane of a muscle cell or nerve cell.

sodium-potassium pump

a carrier protein that uses ATP to actively transport 3 sodium ions out of a cell and 2 potassium ions into the cell

Ligand-gated Na+ channel

They are a group of transmembrane ion channels that are opened or closed in response to the binding of a chemical messenger (i.e., a ligand), such as a neurotransmitter; depolarize (EPSP) as Na+ comes into the cell

Voltage-gated Na+ channel

A Na+-selective channel that opens or closes in response to changes in the voltage of the local membrane potential; it mediates the action potential.

Voltage-gated K+ channel

this channel lets K+ leave the cell, which allows the return of membrane to resting potential after initiation of an action potential

Gap junction

channel between two adjacent animal cells that allows ions, nutrients, and low molecular weight substances to pass between cells, enabling the cells to communicate directly

Bipolar cell

A cell that has two axons

Pseudobipolar neuron

A neuron that contains one axon that splits into two branches

Pyramidal cell

A type of large nerve cell that has a roughly pyramid-shaped cell body; found in the cerebral cortex.

Neurotransmitter

a chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure.

Glutamate

The main excitatory neurotransmitter in the central nervous system. It is involved in memory storage, pain perception, strokes, and schizophrenia.

GABA

gamma-aminobutyric acid; the primary inhibitory transmitter in the nervous system

Dopamine

a neurotransmitter that regulates motor behavior, motivation, pleasure, and emotional arousal

Serotonin

A neurotransmitter that affects mood, hunger, sleep and arousal. Undersupply linked to depression.

Autonomic nervous system

A subdivision of the peripheral nervous system. Controls involuntary activity of visceral muscles and internal organs and glands.

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy (rest and digest)

Parasympathetic ganglia

terminal ganglia (group of neurons) that usually lie close to or in wall of organ they innervate; innervate for parasympathetic processes in the organs (rest and digest)

Acetylcholine (ACh)

A neurotransmitter that enables learning and memory and also triggers muscle contraction; main parasympathetic neurotransmitter

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

sympathetic ganglia

nodules that contain synapses between preganglionic and postganglionic neurons of the sympathetic nervous system. Bundles of neurons that deliver sympathetic information to organ systems (fight or flight)

Neurotransmitters for sympathetic system

Ach in ganglia, Noradrenaline in end organ

anterior pituitary

makes and releases hormones under regulation of the hypothalamus like growth hormone

posterior pituitary

releases oxytocin and ADH

Pituitary hypophyseal portal vein

a system of blood vessels in the microcirculation at the base of the brain, connecting the hypothalamus with the anterior pituitary. Its main function is to quickly transport and exchange hormones between the hypothalamus arcuate nucleus and anterior pituitary gland.

hypothalamic magnocellular cells

neuroendocrine cells located in the hypothalamus, synthesise the hormones arginine vasopressin and oxytocin

hypothalamic parvocellular cells

small neurons that produce hypothalamic releasing and inhibiting hormones; release oxytocin (OT) into various neural sites

Vasopressin

aka ADH; plays essential roles in the control of the body's osmotic balance, blood pressure regulation, sodium homeostasis, and kidney functioning

Thyrotropin releasing hormone

signals the pituitary gland to release TSH (thyroid stimulating hormone)

Growth hormone releasing hormone

Like the name suggests, stimulates secretion of growth hormone :)

dorsolateral hypothalamus

The part of the hypothalamus that produces feelings of hunger, and causes one to begin eating (related to the production of ghrelin, the hunger hormone)

ventromedial hypothalamus

The part of the hypothalamus that produces feelings of fullness as opposed to hunger, and causes one to stop eating.

preoptic nucleus

in hypothalamus responds to signals from the suprachiasmatic nucleus to induce sleep; also related to thermoregulation, male sexual behavior. Releases GnRH

sham rage

a violent reaction to normally innocuous stimuli following removal of the cerebral cortices; incredible rage easily provoked when the cerebral cortex is removed - posterior hypothalamus

Nucleus Accumbens

structure located in the brainstem and part of the dopaminergic reward pathway; releases dopamine in response to many drugs contributing to addictive behavior (dopamine containing neurons)

Amygdala

two lima bean-sized neural clusters in the limbic system; a limbic system structure involved in memory and emotion, particularly fear and aggression.

fear conditioning

A type of classical or Pavlovian conditioning in which the conditioned stimulus (CS) is associated with an aversive unconditioned stimulus (US), such as a foot shock. As a consequence of learning, the CS comes to evoke fear. The phenomenon is thought to be involved in the development of anxiety disorders in humans.

Kluver-Bucy syndrome

a condition, brought about by bilateral amygdala damage, that is characterized by dramatic emotional changes including reduction in fear and anxiety

Capgras syndrome

The delusional belief that an acquaintance has been replaced by an identical-looking imposter. It is more commonly seen in schizophrenia, dementia, and brain trauma.

Toxoplasmosis

a parasite that is most commonly transmitted from pets to humans by contact with contaminated animal feces. Can cause permanent emotional changes like more risk-seeking

orbitofrontal cortex

a region of the brain in which impulses involving excretion, sexuality, violence, and other primitive activities normally arise; a part of the prefrontal cortex located right behind the eyes that participates in impulse control

Insula

regions of cortex located at the junction of the frontal and temporal lobes; cerebral lobe located deep within lateral sulcus; related to emotional processing

circadian cycle

refers to the biological functions that occur within a 24-hour period; rhythm (level of energy) of the human body that varies with the time of day

suprachiasmatic nucleus

a pair of cell clusters in the hypothalamus that responds to light-sensitive retinal proteins; causes pineal gland to increase or decrease production of melatonin, thus modifying our feelings of sleepiness; a cluster of neurons in the hypothalamus in the brain that governs the timing of circadian rhythms

Pineal gland

secretes melatonin (actual usable melatonin is mediated by sunlight bc it gets destroyed when exposed to sunlight - so effects will most likely be felt at night/low-light conditions)

'Third eye' of reptiles

thin patch of skin/bone to let light onto pineal gland, which affects melatonin production

Electroencephalogram (EEG)

An amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.

Awake stage of sleep

low voltage, high frequency beta waves (14-30 Hz); able to perceive, process, access, and express information

Quiet resting period

Alpha waves are predominant here (8-13 Hz); you're a bit drowsy, relaxed, but not asleep

Stage 1 sleep

-Light sleep

-The brain emits theta waves (4-7 Hz)--> consistent with a relaxed state of wakefulness

The state of transition between wakefulness and sleep, characterized by relatively rapid, low-amplitude brain waves.

Stage 2 sleep

second stage of sleep; the body goes into deep relaxation; characterized by the appearance of sleep spindles; theta waves as well

sleep spindles

Short bursts of brain activity that characterize stage 2 NREM sleep.

stage 3 sleep

third stage of sleep; deep sleep characterized by low frequency, high amplitude delta waves (0.5-3 Hz)

stage 4 sleep

the deepest stage of sleep, during which we are least responsive to outside stimulation; delta waves too

beta waves

14-30 Hz

alpha waves

8-13 Hz

theta waves

4-7 Hz

delta waves

0.5-3 Hz