Brain, Spinal Cord, and Nervous Review

brain mass

1300-1400 grams

limbic system

A doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres; associated with emotions such as fear and aggression and drives such as those for food and sex. Includes the hippocampus, amygdala, and hypothalamus.

sulcus

A fold or groove that separates one gyrus from another

gyrus

A fold or raised area of cerebral cortex composed of neuron tissues separated into sections by the sulci and fissures

norepinephrine

A hormone secreted by the adrenal medulla that causes vasoconstriction throughout the body, which raises blood pressure in stressful situations. A neurotransmitter that influences mood and arousal.

Axon

A long projection off the cell body of a neruon down which an action potential can be propagated.

epinephrine

A monoamine neurotransmitter responsible for bursts of energy after an event that is exciting or threatening

hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.

acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

REM sleep

A stage of sleep characterized by rapid eye movements and a high level of brain activity.

thalamus

A structure in the forebrain through which all sensory information (except smell) must pass to get to the cerebral cortex.

sympathetic nervous systems

A subdivision of the autonomic nervous system that activates nerves, glands and visceral muscles in times of stress or threat (prepares the body for action)

parasympathetic nervous system

A subdivision of the autonomic nervous system that calms the body after action and also retains the body functioning at is normal state (homeostasis)

Central Nervous System (CNS)

A subdivision of the human nervous system comprising the brain and spinal cord. Transmits & receives messages to & from the PNS

Autonomic nervous system

A subsystem of the peripheral nervous system that carries messages between the central nervous system and the heart, lungs, and other organs and glands.

corpus callosum

A thick band of axons that connects the two cerebral hemispheres and acts as a communication link between them.

chemical synapse

A type of synapse at which a chemical (a neurotransmitter) is released from the axon of a neuron into the synaptic cleft where it binds to receptors on the next structure in sequence, either another neuron or an organ.

electrical synapse

A type of synapse in which a neuron directly affects an adjacent neuron through the movement of ions from one cell to the other

gray matter

A zone or layer of tissue in the CNS where the neural cell bodies, dendrites, and synapses are found; forms the core of the spinal cord, nuclei of the cerebrum, cerebral cortex, and cerebellar cortex.

Occipital Lobe

An area at the back of each cerebral hemisphere that is the primary receiving area for visual information

dermatome

An area of the skin that is innervated by a single spinal nerve.

Temporal Lobe

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

neuropeptide

Brain chemicals, such as enkephalins and endorphins, that regulate the activity of neurons

convergence

Branches of numerous neurons converging on one or a few neurons. 1000 synapses on 1 neuron

Dendrite

Branchlike parts of a neuron that are specialized to receive information.

cauda equina

Bundle of nerve roots that occupy the vertebral canal from L2-S5. Innervates the pelvic organs and lower limbs.

Efferent nerves

Carry nerve impulses away from the central nervous system to effectors such as muscles or glands.

Afferent Nerves

Carry sensory information. Impulse receptors to CNS. Can be somatic or visceral. From lower to higher centers of the CNS Ex: from skin to spinal cord

myelin

Cell membrane of glial cells (e.g., oligodendrocytes, Schwann cells) wrapped around an axon; increases the speed of impulse conduction along the axon.

glial cells

Cells that provide support for the neurons to grow on and around, deliver nutrients to neurons, produce myelin to coat axons, clean up waste products and dead neurons, influence information processing, and, during prenatal development, influence the generation of new neurons.

Interneurons

Central nervous system neurons that internally communicate and intervene between the sensory inputs and motor outputs.

monoamines

Class of chemicals characterized by a single amine group; includes norepinephrine, dopamine, and serotonin

Soma

Composed of motor nerve fibers (axons). Refers to the voluntary nervous system.

brain stem

Connection to spinal cord. Filters information flow between peripheral nervous system and the rest of the brain.

Peripheral Nervous System (PNS)

Consists of all other nerves in your body, not encased in bone. Divided into somatic and automatic nervous systems.

wernicke's area

Contorls language reception. Damage creates inability to comprehend language; usually in the left temporal lobe

broca's area

Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech

divergence

In neural tissue, the spread of information form one neuron to many neurons; an organizational pattern common along sensory pathways of the central nervous system

frontal lobe

Largest and longest lobe in each hemisphere. Located in the upper forward half. Association areas are involved with planning, problem-solving, personality, decision making, controlling emotions and speech production

Parietal Lobe

Located in the upper back half of the brain. Receives and processes sensory information from the body and skin senses as well as other sensory areas in the brain. Association areas are invovled with spatial reasoning and sensing the position of the body in space.

sciatic

Longest and thickest nerve of the body

Sensory Neurons

Neurons that carry incoming information from the sensory receptors to the brain and spinal cord.

Motor Neurons

Neurons that carry outgoing information from the brain and spinal cord to the muscles and glands.

Autonomic Nervous System

Peripheral nervous system division controlling the glands and the muscles of the internal organs (such as the heart). Its sympathetic subdivision arouses; its parasympathetic subdivsion calms.

saltatory conduction

Rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane.

ventral roots

These nerve roots carry motor impulses from the spinal cord and brain to the body/muscles. Aka Anterior

synapse

a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.

all or none response

a nerve or muscle fibre responds completly or not at all to a stimulus

blood brain barrier

acts as protective mechanism that shelters the brain from potentially harmful substances in blood and fluctuation in concentrations of hormones and ion

Visceral Nervous System

another name for ANS, controls smooth muscle, cardiac muscle, and glands

Nitric Oxide

class- Gas; action- memory

CCK

class- Neuropeptide; action- Gives sensation of fullness after eating (saiety)

GABA

class- amino acid; action- Most prevalent NT in the brain

Acetylcholine

class- cholinergic; action- Skeletal muscle movement

epinephrine

class- monoamines; action- Excites the autonomic nervous system

histamine

class- monoamines; action- Promotes alertness by vasodilation

serotonin

class- monoamines; action- Sleepiness, elevates moods, low levels seen in depression

dopamine

class- monoamines; action- Smoothes out muscle movement; feel good feeling

Neuropeptide Y

class- neuropeptide; action- Gives sensation of hunger

substance P

class- neuropeptide; action- Pain transmitter

beta-endorphin, enkephalins, dynorphins

class- neuropeptide; action- Reduce pain, block substance P

Nuclei within the brain

clusters of gray matter located deeper within the brain

dorsal roots

contain sensory (afferent) fibers that arise from the sensory neurons in the dorsal root ganglia and conduct impulses from peripheral receptors to the spinal cord

pineal gland

located in the center of the brain, functioning to secrete melatonin and serotonin

Neuroepinephrine

the neurotransmitter involved with the sympathetic branch. Sympathetic. Increases heart rate by binding to beta adrenergic receptors, activating an adenylate cyclase (AC) signal transduction pathway that activates a protein kinase that activates the funny and T-type channel, increasing the rate of depolarization of the pacemaker potential.

Refractory Period

the time after a neuron fires or a muscle fiber contracts during which a stimulus will not evoke a response

Somatic Nervous System

Division of the peripheral nervous system that controls the bodies skeletal muscles

nodes of ranvier

Gaps between the myelin sheath. Necessary so signal does not get to weak as it jumps past the myelin sheaths.

Stages of Sleep

NREM1 (lightest sleep, hallucinate), NREM2 (Deep sleep), NREM3 (slow waves), REM.

white matter

Nervous tissue in brain and spinal cord that is composed of myelinated axons

spinal reflexes

Simple pathways in the nervous system that rapidly generate muscle contractions; Simple, automatic behaviors that are processed in the spinal cord.

internodes

The fairly large areas of the axons that are wrapped in myelin