1
Q
ACETYLCHOLINE (ACh)
A
definition: a neurotransmitter found in both the peripheral and central nervous systems
- when it is released into the neuromuscular junction by the peripheral nervous system, it contracts the muscles
- in the central nervous system, ACh is responsible for REM sleep, the maintenance of the circadian rhythm, and memory
- the memory deficits associated with Alzheimer’s disease and other illnesses result from the degeneration of ACh cells in the entorhinal cortex (EC) and other regions of the brain that communicate with the hippocampus
2
Q
TWO TYPES OF RECEPTORS FOR ACH CELLS
A
1: nicotinic receptors - excitatory
2: muscarinic receptors - inhibitory
- nicotine in tobacco products create alertness by mimicking ACh at receptor cites
3
Q
NEURON
A
- sometimes called a nerve cell, instrumental in thought process and behavior
- most of the neurons that a human will ever have are present at birth
- it is possible for neurons to regenerate throughout life
- most neurons have three basic components (dendrites, cell body/soma, and axon)
4
Q
DENDRITES
A
- arms that receive information in the form of electrical impulses from other cells and relay it to the soma
5
Q
CELL BODY (SOMA)
A
- processes information and passes it to the axon, which may then pass it along to other cells
- neurons typically have one axon which divides into a few branches, called collaterals
6
Q
AXONS
A
- covered by a thin, fatty substance known as the myelin sheath, which accelerates the conduction of nerve impulses
- the process through which electrical impulses are passed within a cell is called conduction; communication between cells is performed through the release of neurotransmitting chemicals between the cells (in a gap known s the synapse)
7
Q
GAMMA-AMINOBUTRIC ACID (GABA)
A
- inhibitory neurotransmitter that influences sleep, eating, seizure, and anxiety disorders.
- the development of Huntington’s disease is in part due to the degeneration of the cells in the basal ganglia that are responsible for secreting GABA
8
Q
GLUTAMATE
A
- excitatory neurotransmitter involved in learning and the formation of long-term memories
- when glutamate receptors are overexcited, the result can be seizures and/or brain damage
9
Q
ENDORPHINS
A
- not neurotransmitters but neuromodulators; they have analgesic properties and are thought to lower the sensitivity of postsynaptic neurons to neurotransmitters
10
Q
CATECHOLAMINES
A
- group of neurotransmitters
- includes norepinephrine, epinephrine (adrenaline), and dopamine
- affect personality, mood, memory, and sleep
11
Q
DOPAMINE
A
- instrumental in regulating movement, and in reinforcing substance addition
- elevated levels of dopamine in the mesolimbic areas of the brain are associated with the pleasant feelings engendered by stimulants, opiates, alcohol, and nicotine
12
Q
SEROTONIN
A
- inhibitory in general, and implicated in a broad range of serotonin disorders like depression, schizophrenia, and Parkinson’s disease
- serotonin deficiencies have been one of the factors to blame for ailments such as anorexia, bulimia, obsessive compulsive disorders, migraines, social phobias, and schizophrenia
13
Q
SPINAL CORD
A
- the CNS contains the brain and the spinal cord
- the spinal cord is composed of axons, dendrites, cell bodies, and interneurons
- the job of the spinal cord is to carry information between the brain and the peripheral nervous system, coordinate the right and left sides of the body, and control all of the simple reflexes that do not involve the brain
- the nerve fibers in the superior portion of the spinal cord carry sensory messages, while the nerve fibers in the inferior portion transmit motor messages
- there are 31 sections to the spinal cord, divided into 5 groups (from top to bottom: cervical, thoracic, lumbar, sacral, and coccygeal)
14
Q
SPINAL CORD DAMAGE
A
- when the spinal cord is damaged at the cervical level, the result is quadriplegia
- when the spinal cord is damaged at the thoracic level, the result is paraplegia
- when a spinal cord injury is complete, there will be a total lack of sensation and voluntary movement below the site of the injury
- when the injury is incomplete, some sensory and motor function below the level of injury will be maintained
- if the flow of cerebrospinal fluid (CSF) to and from the four cerebral ventricles is obstructed, then a condition called hydrocephalus may develop in which fluid backs up and there is an enlargement of the ventricles, destroying brain tissue (a similar enlargement of the ventricles has been observed in individuals with schizophrenia)
15
Q
FIVE BASIC STAGES IN THE DEVELOPMENT OF THE CNS
A
- proliferation
- migration
- differentiation
- myelination
- synaptogenesis
16
Q
PROLIFERATION
A
- new cells are produced inside the neural tube; this beings when the embryo is about 2.5 weeks old
17
Q
MIGRATION
A
- (8 weeks) the young neurons move to the appropriate place in the brain and being to form structures
18
Q
DIFFERENTIATION
A
- the neurons begin to develop axons and dendrites
19
Q
MYELINATION
A
- glial cells form an insulating and protective sheath around the axons of some cells
20
Q
SYNAPTOGENSIS
A
- the synapses form; this stage occurs at various periods, depending both on the brains internal schedule, and factors of experience after birth
21
Q
PERIPHERAL NERVOUS SYSTEM (PNS)
A
- composed of nerves in distal parts, not in the spinal cord or brain
- its function is to transmit messages between the CNS and the sensory organs, muscles, and glands
- there are 12 pairs of cranial nerves and 31 sets of sensory and motor nerves that link to the spinal cord
- the PNS is divided into the somatic nervous system (SNS) and the autonomic nervous system (ANS)
22
Q
SOMATIC NERVOUS SYSTEM (SNS)
A
- the SNS controls voluntary motions by relaying messages from the sense receptors to the CNS
23
Q
AUTONOMIC NERVOUS SYSTEM (ANS)
A
- the ANS is primarily concerned with involuntary motions, and connects the viscera to the CNS
- the sympathetic branch of the ANS is associate with arousal and the discharge of energy, while the parasympathetic branch is concerned with relaxation and digestion
24
Q
MIDBRAIN
A
- the midbrain is made up of the reticular formation, which extends from the spinal cord through the hindbrain and midbrain into the hypothalamus structure in the forebrain
- it contains over 90 groups of neurons, with functions ranging from respiration, to coughing, to posture and locomotion
25
RETICULAR ACTIVATING SYSTEM (RAS)
- essential to consciousness, arousal, and wakefulness
- it regulates sensory input, especially during sleep
- when it detects important information, it alerts other parts of the brain
- if an individual suffers damage to his or her reticular formation, his or her sleep-wake cycle may be disrupted; it is even possible to fall permanently asleep as a result of damage to this area
- some anesthetics work by depressing the RAS so that sharp pains do not wake the person up
26
HINDBRAIN
- the medulla and the pons, which are located at the base of the brain near the spinal cord, combine with the cerebellum to form the hindbrain
27
MEDULLA
- the medulla regulates the flow of information between the spinal cord and the brain, and coordinates a number of important process like swallowing, coughing, sneezing, and the heart rate
28
PONS
- the pons bridges the two halves of the brain and is instrumental in coordinating movements between the right and left sides of the body
29
CEREBELLUM
- the cerebellum makes balance and posture possible and contributes to the performance of coordinated and refined motor movements
- autistic individuals have been found to have smaller than normal cerebellums
- a damaged cerebellum may result in ataxia, a condition involving slurred speech, tremors, and a loss of balance
NCMHCE
flashcards
Decks in class (1)
# Cards
