Physiological psych exam 2
Module 3.1: The Central and Peripheral nervous system
-The nervous system has 2 sections the peripheral and central nervous systems
-The central nervous system is composed of the brain and spine
-The peripheral nervous system has the somatic ( sensory output and motor input) and the autonomic which is non voluntary
-The autonomic nervous system sends and receives messages to regulate autonomic behaviors ( heart rate, digestion, respiration, etc.)
-2 subsystems which are sympathetic and parasympathetic nervous system
- The sympathetic nervous system is the fight or flight and the primary neurotransmitter is norephrine
-The parasympathetic nervous system is the rest and digest system and the primary neurotransmitter is acetylcholine
-The spinal cord consists of 2 types of matter: grey matter (center) and white matter (myelinated axons which carry info from grey matter to other areas)
Directions
-Ventral: to the front of towards the stomach
-Dorsal: Back towards the butt
-Anterior: Towards the front
-Posterior: Towards the back
-Superior: above
-Inferior: below
-The hindbrain : pons (hemisphere connecter), medulla (vital reflexes), & cerebellum (balance, sound, spatial reasoning)
-The midbrain: tectum( roof of brain), superior and inferior colliculus ( processes sensory info), & substantia nigra (dopamine booster)
-The forebrain: separated into 2 hemispheres (cerebral cortex and subcortical regions which are the thalamus, hypothalamus, amygdala, hippocampus, olfactory bulb)
- Basal ganglia: Movement, memory, and emotion
-Pituitary Gland: hormone distributor
-Hippocampus: posterior forebrain (memory)
Module 3.2 : The Cerebral Cortex
-There 4 ventricles in the brain are fluid filled cavities that have cerebrospinal fluid (CSF) which act as cushioning for the brain between the skull but this liquid also stores hormones and nutrients
-The meninges are membranes that surround the brain and spinal cord ; have pain receptors
-The cerebral cortex is the brains jacket, its divided into 2 halves that are connected by 2 bundles of axons called the corpus callosum
The 4 Lobes
The frontal lobe has the prefrontal cortex which controls emotional regulation, impulse, decision making, planning. The rest of the frontal lobe controls fine motor movement
The occipital lobe controls vision and is the first stop for all visual input
The parietal lobe is all about sensation because it has the primary somatosensory cortex which is the relay station for all senses where they connect
-The temporal lobe deals with auditory functions, so sound, hearing, and language.
-The prefrontal cortex : posterior(back)=movement / middle= cognitive, emotion, memory/ anterior(front)= decision, reward and value
-The precentral gyrus is the primary motor cortex
-The postcentral gyrus is the primary somatosensory cortex
Module 3.3: Brain Activity and Imaging
-Electronograph (EEG): records electrical activity produced by various regions(poor spatial resolution but good temporal resolution only measures activity on outer cortical layer)
-Positron-emission tomography(PET): positron emitting isotopes attach to reagents in the blood (by injection) and more active areas of the brain require more oxygen and glucose (good spatial resolution but poor temporal resolution)
- functional magnetic resonance imaging (fMRI): more active areas in brain, oxygen consumption in brain provides picture of activation ( good spatial resolution but poor temporal resolution)
Module 5.1 : Vision
-Light enters through the pupil, its then focused by the lens and cornea onto rear surface which is the retina which is lined with visual receptors
-The image is inverted and flipped on the retina and is left to right and top to bottom
-Rods and cones are the primary visual receptor cells
-The fovea is the central portion of the retina which allows for acute and detailed vision
-There are only cones in the fovea which attach to single bipolar cells which attach to ganglion cells which provide a direct line to the brain
-The periphery of the retina has greater numbers of receptors that converge into ganglion and bipolar cells resulting in lower activity and greater light sensitivity.
-Rods are abundant in the periphery and respond to faint light
-Cones are abundant in the fovea, and are essential for color vision, and more useful in bright light
-The 2 major interpretations of color vision are the trichromatic theory + the young-helmholtz theory & the opponent process theory
-The trichromatic theory explains that color perception occurs through the relative rate of response by 3 kinds of cones (short, medium long wavelengths)
-The opponent process theory explains that color perception is in paired opposites, brain mechanisms perceive color on
-Color deficiency is an impairment in perceiving color differences
-Rods and cones make synaptic contact with horizontal cells and bipolar cells
-Horizontal cells mae inhibitory contact with bipolar cells
-Rods and cones make synaptic contact with horizontal cells which make inhibitory contact with bipolar cells which synapse to amacrine cells and ganglion cells which make inhibitory contact with each other
- Lateral Inhibition is the reduction of activity in one neuron by neighboring neurons to sharpen contrast ( makes edges/ corners of objects more defined)
-Ganglion cell axons form the optic nerve and when it leaves the eye (blind spot) it goes the optic chiasm which criss cross
-Most ganglion cell axons go the the lateral geniculate nucleus (LGN)
- The LGN is part of the thalamus and aids the retina in specialized visual perception and sends axons to the occipital lobe
-The receptive field is the part of the visual field that excites or inhibits a cell
-Parvocellular Neurons are highly sensitive bc there is a 1 to 1 cone to bipolar to ganglion cell ratio connection
-Magnocellular Neurons are distributed throughout the retina and have larger cell bodies and visual fields. They are highly sensitive to pattern and moving stimuli
-The primary visual cortex ( Area V1) receives info from the LGN and is responsible for the 1st stages of visual processing
-Simple cells have fixed inhibitory and excitatory zones ( more light =more action potentials fired)
-Complex cells are in the V1 and V2 and have a large receptive field; respond to light in particular orientation
-The ventral stream goes through the temporal lobe and is the “what” path and identifies and recognizes objects
-The dorsal stream goes through the parietal lobe and is the “where or how” path and is important for visually guided movements
-Prosopagnosia: can’t recognize faces because of damage to the fusiform gyrus
Module 6.1: Auditory
-The properties of sound are amplitude and frequency
-Amplitude: intensity of sound wave (volume)
-Frequency: # of compression per sec (Hz and pitch
-The outer ear is the pinna and it is responsible for the concentrating the sound into the middle ear
-The middle ear has the eardrum (tympanic membrane) which vibrates when struck by sound waves, this connects to the ossicles (hammer, anvil, stirrup) which amplify the sound to the oval window (start of the inner ear) which transmits the waves through the fluid in the cochlea.
-The basilar and tectorial membrane than move against each other because of the vibrations which then activate the hair cells to fire action potentials so we hear sound
-The place theory states how each area along the basilar membrane has hair cells sensitive to only one frequency (high frequency)
-The frequency theory: basilar membrane vibrates in synchrony with sound and causes auditory nerves to produce action potentials at the same place (low frequency)
-The primary auditory cortex (Area A1) is the destination for most auditory info and is located in the superior temporal cortex and is contralaterally organized (next to the ears)
-The anterior temporal cortex is the “what” pathway and is sensitive to sound patterns
-The posterior temporal cortex is the “where” pathway and is important for sound localization
-Middle ear deafness is when bones of the middle ear fail to amplify sound waves properly to the cochlea (Fix is hearing aids)
-Inner ear deafness results from damage to the cochlea, hair cells, or auditory nerve (fix is surgery or cochlear implant)
Module 6.2: Sense of Touch
-The 2 types of somatosensory receptors located close the skin are merkel disk which fire consciously while stimulus is present (senses fine detail) and Meissner's corpuscle which fire when applied then removed
-Deeper in the skin are the ruffini endings which perceive stretching of the skin (fire continuously to stimuli) and Pacnian corpuscle which sense rapid vibration and fine texture (fire when applied and removed)
-Pain sensation begins with barre nerve endings and receptors
-Axons carrying pain are unmyelinated and pain intensity depends on how thick the axon is (fire vs garden house)
-Pain triggers the release of glutamate which also releases neuropeptides if intense enough
-Pain information crosses to the contralateral side but touch doesn't till the medulla
-Emotional associations of pain come from painful stimuli which activate a path through reticular formation of the medulla, but also the hippocampus, amygdala, thalamus, etc. (hurt feelings activate the same pathway)
-Opiates bind to receptors in the spinal cord which then release endorphins ( the brain's natural painkillers)