7A Flashcards
sensory neurons
afferent neurons, transmit info from receptors to spinal cord and brain
motor neurons
efferent neurons, transmit motor info from brain and spinal cords to muscles and glands
interneurons
found between other neurons, most numerous. predominately in brain and spinal cord, deal with reflexive behavior
reflex arcs
neural circuits control reflexive behavior, step on nail, foot detects pain and pain signal transmitted by sensory neurons to spinal cord, then interneurons bypass brain and send signals to muscles of leg directly
central nervous system (CNS)
brain & spinal cord
peripheral nervous system (PNS)
made up of nerve tissue and fibers outside the brain and spinal cord. i.e. 12 pairs of cranial nerves and 31 pairs of spinal nerves. connects cns to rest of body, subdivided into somatic and autonomic
somatic nervous system
consists of sensory and motor neurons distributed throughout the skin, joints, and muscles
autonomic nervous system
generally regulates heartbeat, respiration, digestion, glandular secretions, involuntary muscles assc with internal organs and glands
ANS Subdivisions
parasympathetic and sympathetic nervous system
parasympathetic
conserve energy, resting/sleeping states, reduces heart rate/constrict bronchi, increase peristalsis/exocrine secretions, acetylcholine is NT responsible
sympathetic
activated by stress, inc. heart rate, blood to muscles of locomotion, inc. blood glucose, dec. digestion/peristalsis, dilate eyes, epinephrine release
meninges
brain covered with thick sheath of connective tissue, protect brain, keep it anchored with skull, resorb CSF.
3 layers of meninges
dura mater, arachnoid mater, pia mater
dura mater
outermost layer
arachnoid mater
middle layer
pia mater
innermost layer, closest to brain
cerebrospinal fluid
aqueous soln in which brain and spinal cord rest, produced by specialized cells that line ventricles (internal cavities) of brain
three basic brain subdivisions
hindbrain, midbrain, forebrain
brainstem
hindbrain + midbrain, most primitive region of the brain
limbic system
group of neural structures primarily associated with emotion and memory. aggression, fear, pleasure, and pain are related to limbic system
cerebral cortex
most recent evolutionary development of human brain, outer covering of cerebral hemispheres, associated with language processing to problem solving, impulse control, long term planning
forebrain structures (5)
cerebral cortex, basal ganglia, limbic, thalamus, hypothalamus
forebrain function (5 sections)
complex perceptual, cog, behavioral processes/ movement/ emotion, memory/ sensory relay station/ hunger, thirst, emotion
midbrain structures (2)
inferior and superior colliculi
midbrain function
sensorimotor reflexes
hindbrain structures (3)
cerebellum, medulla oblongata, reticular formation
hindbrain function (3)
refined motor movements, vital functioning (breathing, digestion), arousal and alertness
swellings of neural tube
hindbrain (rhombencephalon) - metencephalon, myelencephalon; midbrain (mesencephalon); forebrain (prosencephalon) - telencephalon, diencephalon
hindbrain (rhombencephalon)
controls balance motor coordination, breathing, digestion, general arousal processes. vital functioning essentially vital functioning, divides to metencephalon (medulla oblongata) & myelencephalon (pons/cerebellum)
medulla oblongata
derived from metencephalon, lower brain structure responsible for regulating breathing, heart rate, BP
pons
derived from meyencephalon, contains sensory/motor pways between cortex and medulla, lies above medulla
cerebellum
derived from myencephalon, top of hindbrain, mushrooms out of back of pons, maintains posture and balance, coordinates body movements
midbrain
mesencephalon, receives sensory and motor info from rest of body, involuntary reflex responses triggered by visual (superior colliculus), auditory (inferior)
forebrain
prosencephalon, associated with complex perceptual cognitive behavioral processes, emotion, memory.
telencephalon
cerebral cortex, basal ganglia, limbic system arise
diencephalon
thalamus, hypothalamus, posterior pituitary, pineal gland
neuropsychology
refers to study of functions and behaviors associated with specific regions of the brai
methods used in study the brain
- brain lesions
- stimulating certain parts of cortex and recording brain activity creating cortical maps
- EEG
- rCBF
electroencephalogram (EEG)
involves placing several electrodes on scalp, electrical activity generated by larger groups of neurons, broad patterns of electrical activity can be detected/recorded
regional cerebral blood flow (rCBF)
detects broad patterns of neural activity based on increased blood flow to different parts of the brain
thalamus
important relay station for incoming sensory info all except smell. sorts and transmits sensory impulses to appropriate areas
hypothalamus
lateral and ventromedial, anterior (serves homeostatic fxns) key player in emotional experiences during high arousal states, aggressive behavior, sexual behavior, controls endocrine fxns and ANS, regulate metabolism, balance, temp, water balance, hunger/thirst. *** 4 F’s: feeding, fighting, flighting (sexual) functioning
lateral hypothalamus
hunger center, detects when body needs food and fluids
ventromedial hypothalamus
satiety center, provides signals to stop eating
anterior hypothalamus
sexual behavior, sleep, body temp
posterior pituitary
axonal projections from hypothalamus and is site of release of ADH (vasopressin) and oxytocin
pineal gland
melatonin secretion for regulation of circadian rhythms; direct signals from retina for coordination with sunlight
basal ganglia
coordinate muscle movement as it receives info from cortex and relay this info via extrapyramidal motor system to brain and spinal cord, smooths movements/steady posture
extrapyramidal motor system
gathers info about body position and caries info to CNS
Parkinson’s disease
parts of basal ganglia destroyed, jerky movements, uncontrolled resting tremors
septal nuclei
contain one of primary pleasure centers in the brain
amygdala
defensive/aggressive behaviors
hippocampus
vital role in learning and memory processes, communicates through fornix
gyri & sulci
bumps and folds respectively
cerebral hemisphere
cerebrum divided into two halves
frontal lobe
prefrontal lobe and motor cortex
prefrontal lobe
manages exec fxn by supervising and direction operations of other brain regions. supervises processes associated with perception, memory, emotion, impulse control, and long term planning, assc. area
association area
area that integrates input from diverse brain regions
projection areas
perform rudimentary or simple perceptual/motor tasks
primary motor cortex
located on precentral gyrus in front of central sulcus, initiates voluntary motor movement by sending neural signals down spinal cord toward muscles,
broca’s area
part of frontal lobe, vitally important for speech production, found in only one hemisphere (left)
parietal lobe
located to rear of frontal lobe, central region assc with spatial processing and manipulation - makes it possible to orient oneself and other objects in three dimensional space
somatosensory cortex
located on postcentral gryus (behind central sulcus), involved in somatosensory info processing, this projection area is destination for all incoming sensory signals
occipital lobes
very rear of brain, contain visual cortex (striate cortex), learning/motor control
temporal lobe
auditory cortex, wernicke’s area, memory processing, emotional, language
auditory cortex
primary site of most sound processing, including speech, music, sound info
cerebral hemisphere laterality
communicates contralaterally in some cases, neurons on left side of brain activate movements on right side of body or ipsilaterally (hearing)
dominant hemisphere
heavily stimulated during language reception and production, used to be based on handedness (right hand = left hemi dominant, etc), usually left, analytical function, well suited for managing details - lang, logic, complex voluntary movement, math skills, lang production (broca), language comprehension (wernickes)
nondominant hemipshere
intuition, faces, sense of direction/geometry, creativity, music cognition, spatial processing, simultaneously processes pieces of a stimulus and assembles them into holistic image, intreprets emotional tone of language
influences on behavior (3)
chemical, hereditary, environment
acetylcholine
neurotransmitter found in both central and peripheral nervous systems. in PNS - acetylcholine is used to transmit nerve impulses to muscles. (moving muscles) CNS - acetylcholine has been linked to attention and arounsal
epinephrine, norepinephrine
catecholamines, monoamines, biogenic amines, involved in controlling alertness and wakefulness, NE is local level NT, epi is secreted from adrenal medulla to act systemically as a hormone
dopamine
catecholamine, important role in movement and posture, found in basal ganglia/ too much = schizo
serotonin
monoamine, regulates mood, eating, sleeping, dreaming, depression and mania, too much - manic states
GABA
gamma-aminobutyric acid produces inhibitory post synaptic potentials and is though to play imp role stabilizing neural activity in the brain. cause hyperpolarization of post synaptic membrane
peptide neurotransmitters
neuromodulators, complicated chain of events in postsyn cell than that of regular NTs