Chapter 2 Flashcards
What are the structures in the brain stem?
-medulla oblongata (heart rate, respiration, blood pressure)
-pons (sleep-wake cycle and respiration)
-midbrain (hearing, motor control, alertness)
-reticular formation (alertness in particular)
What is the Thalamus?
-the gateway to the brain
-it receives almost all incoming sensory information before that information reaches the cortex; expect olfactory information
What is the Hypothalamus?
-a brain structure that is involved in the regulation of bodily functions, including body temperature, body rhythms, blood pressure, and blood glucose levels
-it also influences our basic motivated behaviours (aggression, hunger, thirst, sex).
What is the Hippocampus?
-a brain structure that is associated with the formation of new memories
-also memory of arrangements, places, objects
-volume of gray matter found highly correlated with years of experience as a taxi driver (important for navigation)
What is the Amygdala?
-serves a vital role in learning to associate things with emotional responses and in processing emotional information
-special role:
–responding to fear eliciting stimuli
–evaluating facial expressions of emotional significance (strong reaction to fearful face)
–intensification of memories associated with emotional arousal
What affects the learning of behaviour?
-preexisting behavioural tendencies constrain or limit how learning occurs and the extent of learned behavioural change
-much behaviour is elicited:
–bright light causes constriction of the pupils
–respiratory passage irritation leads to sneezing or coughing
–a sudden clap of thunder gets our attention
-the simplest form of elicited behaviour is reflexive behaviour
What are the 2 human spinal orientations?
-the dorsal and ventral aspects of the human spine
–the ventral side of the spinal cord corresponds to the anterior side
–the dorsal side corresponds to the posterior side
What is the nature of elicited behaviour?
-reflex-involves eliciting stimulus and corresponding linked response
-the particular relation between some stimulus and the associated reflex is a consequence of the nervous system organization
What are the 3 different neurons involved in simple reflexes?
- a sensory or afferent neuron
-transmits information to the spinal cord - a motor neuron or efferent neuron
-effects or activates muscles involved in the reflex - an interneuron (one or more) that is an intermediary neuron
-passes information from one neuron (sensory) to
another neuron, such as the motor neuron
What are these 3 neurons responsible for?
-the afferent, interneuron, and the efferent neuron constitute the reflex arc
-because one or more neurons are involved, this is a polysynaptic reflex
-if just two neurons are involved (sensory and motor) it is a monosynaptic reflex (simplest type of reflex)
What are the 3 parts of the polysynaptic pathways in the spinal cord (reflex arc)?
- excitatory pathways, sensory neuron activates motor neurons supplying ipsilateral (same side) flexor muscles, which withdraw the limb from noxious stimuli.
- inhibitory interneurons ensure that the motor neurons supplying antagonist muscles are inactive during the reflex response.
- at the same time, motor neurons supplying contralateral (opposite side) extensor muscles are excited to provide support during withdrawal of the limb
Why do most sensory neurons not pass directly into the brain?
-synpase in the spinal cord
-permits faster reflex actions
-brain receives input while the reflex is being carried out
-brain analyses the information after the reflex action
What are the suckling and rooting reflex?
-innate response due to the stimulation of the face, mouth, or cheek by touching/stroking (the head is turned towards the side of the stimulus).
-brainstem mediated primitive motor reflex also called the frontal release reflex.
What is the respiratory occlusion reflex?
-if a baby’s breathing is inhibited, reflexive actions include:
–head is pulled back
–wiping the face
–or crying if these are not effective
What are the 3 types of motor neurons?
-Upper motor neurons: originate in the cerebral cortex; travel inferiorly to the brain stem or spinal cord; glutamate is the NT
-Lower motor neurons: originate in the spinal cord and innervate glands and muscles; acetylcholine (ACH) is the NT
-Automatic and somatic motor neurons: somatic: alpha, beta, and gamma motor neurons
What are the 4 types of sensory neurons?
-Mechanoreceptors
-Thermoreceptors
-Nociceptors (electromagnetic receptors)
-Chemoreceptors
What are autonomic reflexes?
-autonomic reflexes, largely unconsciously, regulate internal organs smooth muscles and glands
When does the brain mediate a reflexive response?
-reflexes, which are automatic, can be modified by the descending brainstem and cortex pathways
-if you are carrying a kitten and fall, automatic reflexes would normally move to break the fall, but here you do not want to drop the kitten; within 30ms the cortical motor centers would modify the reflexes to allow you to also protect the kitten
What is the process of Puillary light reflex?
-light is flashed near one eye
-impulses reach the brain via the optic nerve
-the response is conveyed to the pupillary musculature (iris muscles)
-pupils contract
What is Modal Action Patterns (MAP)?
-MAP: response sequences typical of a particular species
-many stimuli will elicit different responses from different organisms
–chicks peck a red patch near the tip of the parent’s bill, causing the parent to regurgitate food for them
What is Sign Stimulus?
-specific stimulus that elicits certain response
–when chick peck at their parent’s beak to regurgitate, red spot near the tip is the sign stimulus
What is Supernormal Stimulus?
-exaggerated stimulus used to cause extremely vigorous response
–ex: foods with high levels of sugar and fat cause humans to have much higher rates of salivation and craving than normal food
What are the Sequential Organizations of Behaviour?
-Behaviour Sequence
-Appetitive Behaviour
-Consummatory (completion) Behaviour