brain Flashcards
(15 cards)
the forebrain
cerebral cortex
- distinguishes us from beasts
- outer gray matter layer of cerebral hemispheres = 3mm thick
- 26 bill neurons
- convolutions inc SA & amt of stored info
- mainly glia & cell bodies ==> greyish brown appearance
neocortex (newest part of cortex; 4 lobes) & limbic cortex (older)
forebrain –> cerebral cortex –> 4 lobes
4 lobes of cerebral cortex
F-POT
plus 2 additional subdivisions
1) frontal lobe: speaking, muscle movement, judgement, emotional control
- primary motor cortex: posterior part that controls voluntary movement
- prefronal cortex: anterior part involved in formulating plans & making judgement
- size of frontal lobe related to size of person’s social networks
2) parietal lobe: includes primary somatosensory cortex (anterior part of PL); surface of body “mapped on brain”
- penfield studies
3) occipital lobe: includes primary visual cortex (posterior part of OL), which recieves info from opp visual field
4) temporal lobe: includes primary auditory cortex (superior part of TL), which recieves auditory info
Subdivisions: emotional regulation
- dorsolateral prefrontal cortex (dIPFC): working memory, cognitive flexibility, problem solving, inhibition of rumination/worry
- ventromedial prefrontal cortex (vmPFC): theory of mind (mindreading), self perception, processing risk & fear, behavioral control, decision making
- phineas gage had damage to this area
laterization of function
bundle of interconnecting axons called what? L vs R hemisphere?
- corpus callosum: large bundle of axons that interconnects corresponding regions of association cortex on each side of brain
- L cerebral hemisphere (projects to R side of body): analysis of info, recognition of serial events, language, math (logical, linear)
- R cerebral hemisphere (projects to L side of body): synthesis of info, pattern recognition, ability to percieve things as a whole, identification of emotional expession, non-verbal; holistic
forebrain:
limbic system
- donut shaped system of neural structures at border of brainstem and cerebral hemispheres
- associated with emotions & memory
- includes amygdala & hippocampus
limbic cortex: phylogenetically older part of cortex
limbic system –> amygdala
amygdala
- two almond shaped neural clusters linked to emotion: fear and aggression
- liberals have larger anterior cingulalte cortex (greater ability to cope with conflicting info) while conservatives have larger amygdala (greater ability to recognize threat)
limbic system –> hipocampus
hippocampus
- donut shaped structure important in memory
-
anterior hippocampus portion closest to amygdala involved in regulating behavioral inhibition
- PTSD linked to abnormal activity in this area
limbic system –> ACC
anterior cingulate cortex (ACC)
- forms “collar” around front part of corpus callosum
- function: integrates cognitive & affective info, awareness & processing of conflicting info; selective attention, pain perception, impulse control
(other regions of forebrain)
insular cortex
- deep within lateral sulcus (fissure sep TL from P and FL)
- functions: body awareness, sense of self, emotional experience, empathy & compassion, addiction
(high conciousness, being present)
(other regions of forebrain)
basal ganglia
- at base of forebrain & top of midbrain
- upper part: caudate nucleus, putamen, globus pallidus: important in action selection, motor sequencing, motor inhibition
- lower part: nucleus accumbens – important in reward learning
(other regions of forebrain)
nucleus accumbens
- lower part of basal ganglia
-
reward center of brain– addiction involves release of dopamine from ventral tegmental area (VTA) and substantia nigra into this area
- parkingson’s disease characterized by loss of dopaminergic neurons in this area
(other regions of forebrain)
thalamus & hypothalamus
thalamus
- located in center of brain
- relay station for neural messages: directs messages to sensory recieving areas in cortex & transmits replies to cerebellum & medulla
hypothalamus
- small but important neural structure beneath thalamus
- controls autonomic nervous system
- controls anterior & posterior pituitary glands
- organizes behavior related to survival: including four f’s: fighting, feeding, fleeing, mating
(other regions of forebrain)
pituitary gland
- attached to base of hypothalamus
- controlled by hypothalamic hormones
- secretes hormones that coontrol other endocrine glands including:
-* gonadotropic hormones *that stimulate release of sex hormones by ovaries and testes- oxytocin (cuddle hormone) involved in social bonding & breastfeeding
- vassopressin which regulates urine output by kidneys and plays role in pair bonding
(other regions of forebrain)
parts of brain important in regulation of emotion
- amygdala: seat of emotions, particularly negative emotions liek fear & aggression
-
prefrontal cortex (PFC) and anterior cingulate cortex (ACC): set goals, make plans, direct action, shape emotions (in part by guiding/inhibiting limbic system)
- emotional dyscontrol often associated with overactive amygdala and underactive PFC/ACC
midbrain (2 parts)
brain stem
- oldest and central core of brain, beginning where spinal cord swells as it enters the skull
- responsible for automatic survival function
reticular formation
- large network of neural tissue in central part of brain stem
- plays part in sleep, arousal, attention, and various vital reflexes
instinctual, reptilian brain
hindbrain (3 parts)
- pons: bulge in brain stem that is part of reticular formation & is important in sleep and arousal, as well as sensory analysis & movement
- medulla oblongata: base of brainstem; controls vital functions, heart rate, breathing, blood pressure
- cerebellum: “little brain” attached to rear of brainstem; coordinate voluntary movement & balance
