Biology and Behavior Flashcards
Afferent neurons
- sensory neurons
- transmit sensory info receptor->spinal cord/brian
Efferent neurons
- motor neurons
- motor info brain/spinal cord->muscles/glands
Interneurons
- b/ neurons
- common in reflexes
- most numerous
- predominantly in brain/spinal cord
Division of NS
- Central (brain and spinal cord)
- Peripheral (including 31 pairs of spinal and 12 pairs of cranial nerves).
- Somatic (voluntary)
- Autonomic (involuntary, include sympathetic and parasympathetic)
Sympathetic NS
- activated by stress
-flight-or fight
-dilate pupils
-inhibits salivation
-relax bronchi
increase HR - increase sweating/polierection
-X peristalsis, secretion
-stimulates glucose production and release
-neurotransmitter: adrenalin and noradrenaline
-Xbladder contraction - stimulates orgasm
Parasympathetic NS
opposite of sympathetic NS
- neurotransmitter: Ach
- rest and digest
Meninges
- sheath of CT
-protection
-anchores brain to the skull
-resorbs CSF
composed of three layers :
1. dura mater (outer)
2.Arachnoid mater
3.Pia mater
CSF
aqueous solution in brain and spinal cord
- protect
- produced by ventricles in the brain
Major division of brain
- Forebrain (include cerebral cortex, basal ganglia, limbic system, thalamus, hypothalamus)
- Midbrain (include inferior and superior colliculi)
- Hindbrain (cerebellum, medulla oblongata, reticular formation)
Subdivision of embryonic brain
- developed from neural tube that first develop three swelling for forebrain, midbrain and hindbrain.
- swelling for hindbrain and forebrain swell into 2, forming 5 swelling all together
Hindbrain structure and development
- located at juncture with spinal cord
- aka rhombencephalon
- in embryonic development: divides into myelencephalon (->medulla oblongata) and metenccephalon (->pons and cerebellum
- include cerebellum, medulla oblongata, reticular formation
CErebelum
- part of hindbrain
- developed from metencephalon
- motor memory
- refined motor movements
- posture and balance
- coordination of body movements
- damage: clumsiness, slurred speech, loss of balance
Medulla oblongata
- part of hindbrain
- developed from myelencephalon
- vital functions (breathing, digestions, HR, BP)
Reticular formation
- hindbrain
- from metencephalon
- arousal and alertness
Midbrain
- aka mesencephalon
- receives sensory/motor info from the rest of the body
- involuntary reflexes trigered by visual/auditory stimuli
- include superior and inferior colliculus
Superior colliculus
part of midbrain
receives visual sensory input
MNEMONIC: HARD LETTER FOR HARD LETTER (S->V)
Inferior colliculus
midbrain
auditory sensory input
MNEMONIC: VOVEL FOR VOVEL (I->A)
Forebrain
- during development divides to form telencephalon (cerebral cortex, basal nuclei, limbic system) and diencephalon (thalamus, hypothalamus, posterior pituitary, pineal glands)
- aka prosencephalon
functional techniques of neuroimaging
- PET (follows ingection and absorbtion of radioactive sugar in the brain
- fMRI (measures changes associated w/ blood flow)
- EEG ( measure brain activity for longer periods of time, records electrical activity)
- regional cerebral blood flow (rCBF): detects neural activity based on changes to blood flow
structural techniques of neuroimaging
- CT
2. MRI
Thalamus
- relay station for sensory info except smell
- sorts and transmits to correct part of cerebral cortex
Hypothalamus: functions
- hunger and thirst
- endocrine functions
- homeostasis
- regulates ANS
- drives sex behaviour
- regulates functions of pituitary glands via hypophyseal portal system
Hypothalamus: subdivision
- Lateral
- Ventromedial
- Anterior
Lateral Hypothalamus
MNEMONICS: when the Lateral Hypothalamus (LH) is destroyed, one Lacks Hunger
trigger eating and drinking
Ventromedial hypothalamus
MNEMONICS: when VMH is destroyed, one is Very Much Hungry
- satiety centre
- gives signal to stop eating
Anterior Hypothalamus
MNEMONICS: when Anterior hypothalamus is damaged, one is Asexual
- sexual behaviour
- sleep
- body t
Ghrelin
hormone that increases hunger
Pineal Gland
secrete melatonin (regulates circadian rhythm)
Basal ganglia
- coordinate muscle movements
- make movements smooth and posture steady
- disease: Parkinson’s, OCD, schizophrenia
Limbic system
- memory nad emotions
- composed of septal nuclei, amygdala, hippocampus
Septal Nuclei
pleasure center
Hippocampus
- learning and memory
- consolidates info to form long-term memories
Anterograde amnesia
- inability to make new memories
- old memories remain intact
Retrograde amnesia
- memory loss of events prior to the injury
Cerebral cortex
- outer surface
- aka neocortex
- made of gyri and sulci
- divided into 2 hemisphere and 4 lobes
Frontal lobe
composed of
- Prefrontal cortex:
- supervising and directing operations of other brain regions
- perception, memory (reminding us to remember to do something), emotion, impulse control, long-term planning
- if damaged: impairs supervisory functions, more impulsive, less control, vulgar language and behavior, apathetic
- Primary motor cortex:
- initiates voluntary movements
- a projection area
- motor homunculus
Association area
area that integrates input from diverse brain regions
- complex processing
Projection area
performs simple perceptual and motor tasks
Broca’s area
frontal lobe
speech production
found in dominant hemisphere
Parietal Lobe
somatosensory cortex in postcentral gyrus:
- ivolved in somatosensory info processing
- projection area
- somatosensory homunculus
spacial processing and manipulation
Occipital lobe
visual cortex
learnign and motor control
Temporal Lobe
- auditory cortex: sound processing
- WErnicke’s area: language comprehension and reception
memory processing, emotions, language
Contralaterraly
on the opposite side of the bosy
ipsilaterraly
on the same side of the body
Dominant hemisphere
- usually L
- analytic in function
- language content, logic, math
Nondominant hemisphere
- usually R
- emotions, intuitions, creativity, spacial processing
Ach
- CNS: attention and arousal
2. PNS: PSNS, nerve impulse transmission to muscles (voluntary)
Catecholamines
- include EN, Epinephrin and dopamin
- role in experiencing emotions
Epinephrine
- aka adrenaline
- secreted from adrenal medulla
- acts as hormone
- SNS
- flight-or-fight
- alertness and wakefulness
Norepinephrine
- aka noradrenaline
- SNS
- flight-or-fight
- alertness and wakefulness
- acts at local level
- low levels: depression
- high levels: anxiety and mania
Dopamine
- movement and posture
- usually high levels in basal ganglia
- disbalances associated with
1. schizophrenia (too much or oversensitivity to dopamine)
2. Parkinson’s disease (loss of dopamine neurons)
Serotonin
mood eatin sleeping dreaming ovversupply: mania undersupply: depression
GABA
- produces inhibitory postsynaptic potentials
- stabilizes neural activity in the brain
- causes hypoerpolarization of postsynaptic membrane
Glycine
- inhibitory neurotransmitter in CNS
causes Cl influx -> hyperpolarization of postsynaptic neuron
Glutamate
- excitatory neurotransmitter in CNS
Endorphines
- natural painkillers produced in brain
- type of neuromodulator (peptide neurotransmitter): have slower, but longer effect
Cortisol
stress hormone
Adrenal gland
- on top of kidney
- adrenal medulla: Epi, NE
- adrenal cortex: corticosteroids (including cortisol). testosterone, estrogen
Innate behavior
- genetically programmed
- seen in everyone
Learned behavior
- based on experience and envi
Family studies
- rely on assumptions that family members are more similar genotypically than unrelated individuals
- limited because can’t separate nature vs nurture
Twin studies
compares likelihood that both twins exhibit the same trait (between monozygotic (identical) and DZ twins)
Adoption studies
compare similarities b/ adopted children and their adoptive parents, raletive to similarities w/ their biological parents
NS development
thru neurulation: notochord stimulates ectoderm to fold over and create neural tube (becomes CNS) topped with neural crest (differentiates into many different tissues)
Primitive reflexes
- dissapear with age
- include : rooting reflex, Moro, Babinski, grasping
rooting reflex
turning of the head in the direction of a stimulus that touches cheek
Moro reflex
extens the arms, then slowly withdraws them and cries
- dissapears after 4 months
Babinski reflex
big toe extends while other toes fan outwards
MNEMONICS: Babinski sounds like something big (toe)
Grasping reflex
closure of fingers when something is put on the hand
Developmental milestones
- gross and fine motor abilities progress head to toe and core to periphery
- social skills shift from parent->self->others
- language skills become increasingly complex
