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Flashcards in Chapter 2 Deck (119):
1

Neuroplasticity

nervous system’s potential for physical or chemical change that enhances its adaptability to environmental change; ability to compensate for injury

2

Phenotypic plasticity

the individual’s capacity to develop into more than one phenotype—characteristics that can be seen or measured

3

Central Nervous System (CNS)

brainstem, forebrain, and spinal cord

4

Somatic Nervous System (SNS)

all the spinal and cranial nerves carrying sensory information to the CNS from the muscles, joints, and skin; transmits outgoing motor information→ movement

Motor innervation of all skeletal muscles

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Autonomic Nervous System (ANS)

balances the body’s internal organs to “rest and digest” through the parasympathetic (calming) nerves or to “fight or flee” or engage in vigorous activity through the sympathetic (arousing) nerves

Motor innervation of smooth muscle, cardiac muscle, and glands

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Afferent

incoming information

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Efferent

outgoing information

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Meninges

layered, protective covering of the brain. Includes the outer dura mater (tough double layer of fibrous tissue that encloses the brain and spinal cord in a lose sac), the arachnoid layer (thin sheet of delicate connective tissue that follows the brain’s contours), and the pia mater (moderately tough membrane of connective-tissue fibers that cling to the brain’s surface)

9

Subarachnoid space

filled with cerebrospinal fluid (CSF) from the 4th ventricle

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Ipsilateral

structures that lie on the same side

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Contralateral

structures that lie on opposite sides

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Bilateral

structures that lie in each hemisphere

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Proximal

structures that are close to one another

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Distal

structures that are far from one another

15

Anterior

located near or toward the front of the animal or the front of the head (frontal; rostral)

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Caudal

located near or toward the tail of the animal (posterior)

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Coronal

cut vertically from the crown of the head down; used in reference to the plane of a brain section that reveals a frontal view

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Dorsal

On or toward the back of the animal, or in reference to human brain nuclei, located above; in reference to brain sections, a viewing orientation from above

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Frontal

“of the front”; in reference to brain sections, a viewing orientation from the front

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Horizontal

Cut along the horizon; used in reference to the plane of a brain section that reveals a dorsal view

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Inferior

located below (ventral)

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Lateral

toward the side of the body or brain

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Medial

toward the middle, specifically the body’s midline, in reference to brain sections, a side view of the central structures

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Posterior

located near or toward the tail of the animal (caudal)

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Rostral

“toward the beak” (front) of the animal (anterior; frontal)

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Sagittal

cut lengthways from front to back of the skull; the plane that reveals a view into the brain from the side; a cut in the midsagittal plane divides the brain into symmetrical halves, a medial view

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Superior

located above (dorsal)

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Ventral

on or toward the belly or the side of the animal where the belly is located; in reference to brain nuclei, located below (inferior)

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Gyri

bumps in the brain’s folded surface

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Sulci

cracks in the brain’s folded surface

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Fissures

very deep sulci

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Cerebrospinal Fluid

a colorless solution of sodium chloride and other salts; cushions the brain so that it can move or expand slightly without pressing on the skull

33

Cerebral Cortex (neocortex)

part of the forebrain; made up of four lobes; the surface of the brain is a thin sheet of nerve tissue that is folded many times to fit inside the skull; regulates a host of mental activities ranging from perception to planning; comprises 80% of the human brain

34

Temporal Lobe

side of the brain; hearing and language and musical abilities

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Frontal Lobe

performs the brain’s executive functions (decision making)

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Parietal Lobe

top of skull, behind frontal lobe and above temporal lobe; parietal functions include directing our movements toward a goal or to perform a task (grasping an object), spatial issues, attention 

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Occipital Lobe

back of each hemisphere; visual processing begins

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Brainstem

responsible for most unconscious behavior and basic physiological functions; begins where the spinal cord enters the skull and extends upward into the lower areas of the forebrain. Receives afferent nerves coming in from all of the body’s senses and it sends efferent nerves out to the spinal cord to control virtually all of the body’s movements (except the most complex movements of fingers/toes). Three regions→ hindbrain, midbrain, between brain (diencephalon); each performs more than a single task (both sensory and motor functions)

 

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Major Cerebral Arteries

three (anterior, middle, posterior) that sent blood to the cerebrum

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Stroke

blockage or break in a cerebral artery that is likely to lead to the death of the affective region; sudden appearance of neurological symptoms as a result of severely interrupted blood flow

41

Ischemic stroke

blood vessel is blocked (clot); can be treated acutely with a drug called tissue plasminogen activator (t-PA) that breaks up clots and allows a return of normal blood flow to an affected region

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Hemorrhagic stroke

burst vessel bleeding into the brain

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Gray matter

composed of cell bodies and capillary blood vessels; neurons of the gray matter function either to collect and modify information or to support its activity

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White matter

composed mostly of nerve fibers with fatty coverings that produce white appearance; form the connections between cells

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Ventricles

brain contains four ventricles that contain the cerebrospinal fluid; cells that line the ventricles make the cerebrospinal fluid that fills them; may play an important role in maintaining brain metabolism

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Corpus callosum

band of white matter containing about 200 million nerve fibers that connects the two cerebral hemispheres to provide a route for direct communication between them; simliarly connected on both sides

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Cerebral Aqueduct

runs the length of the spinal cord; the third and fourth ventricles drain into it

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Neurons

carry out the brain’s major functions; aka pyramidal cell because it is shaped like a pyramid

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Glial cells

modulate the neuron’s activities (ex. Insulating neurons); 10:1 ratio for glial cells to neurons; there are different shapes/kinds

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Nuclei

clusters of similar cells

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Axon

connect neurons; axons that run together that form nerves (outside the CNS) or a tract (inside the CNS)

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Nervous System Development

young vertebrate embryo→ sheet of cells that folds into a hollow tube and develops into three regions: forebrain, midbrain, and hindbrain (located at the end of the embryonic spinal cord)

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Spinal Cord

—18 Inches long; —Housed within spinal column made up of the vertebrae and disks; —Each nerve corresponds to specific body location; —Identified by exit points based on vertebrae level; —Sends sensory and motor information to/from trunk and limbs; can act independently as well; Contains: dorsal roots, ventral roots, white matter (outer part), and gray matter (inner part)

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Dorsal Root

a collection of dorsal fibers enter the spinal cord segment; are afferent (carry in information from the body’s sensory preceptors); sensory 

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Ventral Root

a collection of ventral fibers leaving the spinal cord segment; are efferent (carry information out from the spinal cord to the muscles); motor    

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Law of Bell and Magendie

the general principle that sensory fibers are located dorsally and motor fibers are located ventrally

57

Spinal Nerves

part of the SNS carry sensory information to the cord from the skin, muscles, and related structures and in turn send motor instructions to control each muscle

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Spinal Reflex

automatic

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 Cerebellum

the relative size increases with the physical speed/dexterity of a species; looks like cauliflower; contains three subparts--reticular formation; pons; medulla; contains 50% of brain's neurons; controls coorindated movement and is involved with thinking/language

60

Reticular Formation

part of brainstem; ill-defined netlike mixture of neurons (gray matter) and nerve fibers (white matter) from upper spinal cord to thalamus; Defined by physiologic characteristics of cells; Involved in tonic level of arousal, drowsiness, sleeping, coma

61

Pons

termination point for cranial nerves; nuclei receive inputs from the cerebellum and form a bridge from it to the rest of the brain; nuclei for respiration, swallowing, bladder control, eye movement 

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Medulla

continuous with spinal cord; contains substructures that control vital movements of the body; nuclei control vital functions (breathing, cardiovascular system, blood pressure) 

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Tectum

Part of midbrain; receives sensory information from ears and eyes; optic nerve sends a large bundle of nerve fibers to the superior colliculus and the inferior colliculus receives much of its input from auditory pathways; Colliculi process sensory information and also produce orienting movements related to sensory inputs (turning head to see source of sound) 

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Tegmentum

Part of midbrain; composed of many nuceli primarily with movement-related functions; several control eye movements; contains: red nucleus, substantia nigra, periacqueductal gray matter

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Hypothalamus

part of the diencephalon (between brain); composed of 22 small nuclei and nerve-fiber systems that pass through it.  Controls body’s production of hormones via pituitary gland; takes part of all aspects of behavior including feeding, sexual behavior, sleeping, temperature regulation, emotional behavior, hormone function, and movement

66

Thalamus

part of the diencephalon (between brain); contains 20-odd nuclei and is much larger than the hypothalamus; is a gateway for channeling sensory information traveling to the cerebral cortex systematically; all sensory systems send inputs to the thalamus for information integration and relay to the appropriate area in the cortex; routes may be indirect; some regions have motor functions or perform integrative tasks

67

Neocortex

aka cerebral cortex; part of the forebrain; newest cortex; tissue that is visible when we view the brain from the outside; primary function is to create a perceptual world and respond to that world; has six layers of gray matter atop of white matter and has distinct characteristics (different layers have different types of cells, density of cells in each layer varies; other differences in appearance relate to functions of the cortical layers in different regions; connected to all other parts of the brain; creates our reality

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Limbic Cortex

part of the forebrain; oldest cortex; plays a role in controlling motivational states

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Basal Ganglia 

part of the forebrain; controls voluntary movement; collection of nuclei that consists of three principle structures--caudate nucleus, putamen, globus pallidus (substantia nigra & subthalamic nuclei); disorders of controlling movement (Parkinson’s & Tourette’s); not involved with actually activating the muscles to move

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Limbic System

part of the forebrain; regulates emotions and behaviors that create and require memory; roles in emotion, sexual behaviors, memory, motivation; contains--amygdala, hippocampus, limbic/ cingulate cortex (in the cingulate gyrus); rewarding properties of psychoactive drugs and other potentially addictive substances

71

Injury to the Lobes

-occipital: deficits in processing visual information; may be able to perceive light/dark but unable to identify shape or color

-parietal: difficult to identify and locate stimulation on the skin; deficits in making arm movements or pointing

-temporal: difficulty recognizing sounds and processing complex visual information (faces)

-frontal-lobe: difficulty organizing thoughts and ongoing behavior or future planning

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Hippocampus

part of the limbic system; memory, navigating space; bilateral damage=difficulty retaining new info

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Cingulate Cortex

part of the limbic system; memory, navigating space; 

74

Olfactory System

olfactory bulbs are located at the front of the brain; sense of smell; sends input to the pyriform cortex at the bottom of the brain, before progressing to the dorsal medial thalamus and then onto the frontal cortex; sensitive and plays a role in feeding and sexual behavior 

75

Cranial Nerves

afferent functions (sensory inputs to the brain from the eyes, ears, mouth, nose) and efferent functions (control of facial muscles, tongue and eyes); some have both sensory and motor functions; 12 pairs of nerves—one set controls the right side of body, the other the left; contribute to maintaining autonomic functions by connecting the brain and internal organs and but influencing other autonomic responses (salivation)  

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Cranial Nerves

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Spinal Nerves

(peripheral nerves) made up of sensory and motor nerves; receive information from the PNS; nerves on the left side of spinal cord control the left side of body, etc

78

Sympathetic Division

part of the ANS; arouses the body for action (fight or flight); activation starts in the thoracic and lumbar spinal-cord regions.  Spinal cord is corrected to the autonomic control centers, which are collections of ganglia (control the internal organs).  Sympathetic ganglia are located near the spinal cord, forming a chain that runs parallel to the spinal cord 

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Parasympathetic Division

calms the body down (rest and digest); connected through the spinal cord primarily through three cranial nerves (vagus nerve, facial nerve, oculomotor nerve); connects with ganglia near the target organs

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Vagus Nerve

calms most of the internal organs

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Facial Nerves

controls salivation

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Oculomotor Nerves

controls pupil dilation

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Excitation

increase in neuron activity

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Inhibition

decrease in neuron activity 

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Alzheimer's Disease 

degenerative brain disease related to gaining that first appears as progressive memory loss and only much later develops into generalized dementia Al

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  1. The nervous system produces movement within a perceptual world the brain creates
  2. The hallmark of nervous-system functioning is neuroplasticity
  3. Many of the brain’s circuits are crossed; olfactory sensation projects ipsilaterally and the cranial and spinal nerves are also connected ipsilaterally
  4. The central nervous system functions on multiple levels
  5. The brain is both symmetrical and asymmetrical
  6. Brain systems are organized both hierarchically and in parallel
  7. Sensory and motor divisions exist throughout the nervous system
  8. Sensory input to the brain is divided for object recognition and motor control
  9. Functions in the brain are both localized and distributed
  10. The nervous system works by juxtaposing excitation and inhibition

87

Dura Mater

part of the meninges; tough double layer of fibrous tissue that encloses the brain and spinal cord in a lose sac

88

Arachnoid Layer

Part of the meninges;thin sheet of delicate connective tissue that follows the brain’s contours

89

Pia Mater

Part of the meninges; moderately tough membrane of connective-tissue fibers that cling to the brain’s surface

90


—Microglia
 

Type of glial cell; 

Migrate to damaged areas as needed to dispose of pathogens and neuronal debris
 

91

Astrocytes

Type of glial cell; 
—Star shaped, metabolic regulation of microenvironment, response to brain injury

92


—Oligodendrocytes
 

Type of glial cell; 
—Mainly in white matter, primary role is mylenation of axons

93


—Ependymal Cells
 

Type of glial cell; 
—Form epithelium that produces CSF

94

Pruning

—Neurons and Synapses initially over produced and development eliminates (prunes) large numbers of neurons; synaptic connections that have been strengthened are spared.


—Up to 40% of neurons eliminated by adolescence and early adulthood
 

95

PNS

Sensory (afferent) division: 

  1. Somatic Sensory
  2. Visceral Sensory

Motor (efferent) division

  1. Somatic Nervous System
  2. Autonomic Nervous System
  • Sympathetic
  • Parasympathetic

96

Somatic Sensory

General: touch, pain, pressure, vibration, temperature, and proprioception in skin, body wall and limbs

Special: hearing, equilibrium, vision

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Visceral Sensory

General: stretch, pain, temperature, chemical charges, and irritation in viscera; nausea and hunger

Special: taste, smell

98

Regions of the Spinal Cord

top to bottom--> cervical, thoracic, lumbar, sacral, and coccygeal;

99

What are segments of the spinal cord called?

dermatome

100

Choroid Plexus

housed in lining of ventricles; produces enough CSF to flush system 4x a day

101

Foramen of Monro

empties CSF from lateral ventricles into the third ventricle

102

Cerebral Aqueduct

Empties CSF into the fourth vebtricle

103

Tectum

 

Part of the midbrain; roof; sensory component; consists of the inferior and superior colliculus 

104

Tegmentum

Part of the midbrain; motor structure; floor; dorsal

105

Inferior Colliculus

Part of the Tectum; auditory orienting

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Superior Colliculus

Part of the midbrain; visual orienting

107

Thalamus

relays sensory info except olfaction; major pathway for motor systems; implicated in attention

108

Thalamic Syndrome

Deficits in sensory and motor functions, including pain

109

Striatum

Caudate, putamen

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Basal Ganglia Loops

Cortico-Striato-Pallido-Thalamo-Cortical loops: important in implementing thought into action; initiating involuntary movements; can potentially bypass a damaged loop; Parkinson's

111

Amygdala

has cortical, thalamic, and hippocampal connections; emotional processing (fear), damage=rage/passivity

112

Capgras' Syndrome

Type of delusion--believes that things in their life are impostures because of damage to the amygdala creating the appropriate emotional response to what we are seeing/hearing 

113

Orbital Medical Cortex

has important connections with the limbic system; emotional processing of info

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Frontal Lobe Damage: Problems

  1. Problems of startings
  2. Difficulties in mental & behavioral shifting
  3. Problems in stopping "disinhibition"
  4. Deficient self-awareness
  5. Concrete thinking

115

Lateralization

  • Left--dominant for language (70% right handed/left hemi; 10% left handed/right hemi; 20% mixed)
  • Right---spatial attention; language prosody, constructional ability

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Red Nucleus

Part of tegmentum (midbrain);  controls limb movements

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Substantia Nigra

Part of tegmentum (midbrain); connected to the forebrain and is important in initiating movements

118

Periacqueductal Gray Matter

Part of tegmentum (midbrain); made up of cell bodies that surround the aqueduct joining the third and fourth ventricles—contains circuits controlling species typical behaviors (female sexual behavior) and help modulate pain via opioid drugs  

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