Module 6 Flashcards
Describe the brain stem
controls some of the most basic/involuntary functions (heart rate and respiration); made up of midbrain, pons, and medulla oblongata; incorporates 9 cranial nerves
Define gyri and sulci
gyri are bumps on the brain and sulci are dips on the brain
Describe the frontal lobe, its parts and functions
EXECUTIVE FUNCTION, primary motor cortex for movement, premotor cortex integrates movement info with sensory info/event sequencing, prefrontal cortex processes skeletal muscle inputs/decision making/behaviour
Describe the parietal lobe, its parts and function
SENSORY PERCEPTION, primary somatosensory cortex receives input from major sensory organs, somatosensory association areas for cortex integration (integrates sensory info with other association areas to form meaningful perceptions)
Describe the temporal lobe, its parts and functions
AUDITORY PROCESSING, MEMORY, OBJECT AND PATTERN RECOGNITION, primary auditory cortex and associated areas for auditory processing, other portions for olfaction(smell), short-term memory and language
Describe the occipital lobe, its parts and functions
VISION, primary visual cortex for vision input from optic nerve, visual association areas for vision integration (processing visual info and integrating with other sensory inputs)
Describe the cerebellum and its functions
processes sensory info and coordinates execution of movement, has largest number of neurons in brain; receives input from somatic receptors, equilibrium receptors, and balance and motor neurons from cortex
Describe the corpus callosum and its function
dense bundle of nerves; a pathway/connection between two cerebral hemispheres, allowing integration of info from both sides of body and coordinating whole body movement
Describe the diencephalon, its parts and functions
thalamus receives sensory input from spinal cord and sends it to cortex; hypothalamus controls variety of endocrine functions (body temp, thirst, food intake, etc) through directing release of hormones
Describe the pituitary gland, its parts and functions
regulates other endocrine organs, regulated by hypothalamus; anterior is derived from epithelial tissue of pharynx and releases LH, FSH, ACTH, TSH, GH and prolactin; posterior derives from neural tissue of hypothalamus, releases vasopressin and oxytocin
Describe the midbrain and functions
bridges lower brainstem with above, controls eye movements, exerts control over auditory and visual motor reflexes
Describe the pons and functions
acts as relay station for transferring info between cerebellum and cerebral cortex; the bump in center of brainstem between midbrain and medulla
Describe the medulla and functions
primary control over involuntary functions like breathing, blood pressure, swallowing; fibers from corticospinal tract (originating in motor cortex) cross over to opposite side here
Describe the optic nerves and functions
optic nerve meet at optic chiasma, cross over and continue to thalamus, where axons then extend to primary visual area of occipital love
Describe primary motor cortex, location and function
at posterior end of frontal lobe; processes info relating to skeletal muscle movement, stimulation causes specific muscles to contract (arrangement is very specific)
Describe primary somatosensory cortex, location and function
at anterior end of parietal lobe; receives sensory info from opposite side of body like pain, temp, touch, and vibration
Describe language and mathematical area, location and function
most often in left hemisphere (regardless of dominant hand); general interpretive center, allows understanding of visual and auditory info and generates written and spoken responses
Name the two main types of brain cells
neurons and glial cells
Name the 3 basic types of neurons
bipolar, unipolar, and multipolar
Describe bipolar neurons
two processes extending from cell body, specialized neurons found in retina of the eye
Describe unipolar neurons
one process extending from cell body, located in peripheral nerves outside CNS, generally sensory, transmit signals to and from spinal cord
Describe multipolar neurons
branching dendrites and one axon, most common in CNS
Describe glial cells and their function
make up 90% of brain, provide necessary environment for neurons to function properly; support cells maintain internal environment of CNS, perform structural role, regulate nutrients; 3 types: astrocytes, microglia, and oligodendrocytes
Define neural coding
the heavier the object, the more APs per second, this way the weight of the object is coded into the AP
Name 3 main parts of chemical synapse and important parts in each
axon terminal of presynaptic cell (voltage-gated Ca++ channels, synaptic vesicles with neurotransmitter, mitochondria); synaptic cleft; postsynaptic cell (chemical receptors, chemically-gated ion channels react to neurotransmitter)
Name 4 classes of neurotransmitters
acetylcholine (ACh); biogenic amines (catecholamines like dopamine, epinephrine); amino acids (excitatory like glutamate, inhibitory like GABA and glycine); neuropeptides (endogenous opioids like endorphin, and VIP)
Name the most common excitatory neurotransmitter
Glutamate (amino acid)
Name the most common inhibitory neurotransmitter
GABA (amino acid)
Name the main difference between the NMJ and chemical synapse
NMJ has single AP in neuron produce single AP in muscle causing muscle contraction; chemical synapse has single AP in presynaptic neuron that will not produce or even guarantee an AP in postsynaptic neuron
Define EPSP and general events
Excitatory Post-Synaptic Potential; caused by excitatory neurotransmitter opening ligand-gated channels, allowing Na+ into cell causing local depolarization; strong enough depolarization may cause AP at axon hillock
Define IPSP and general events
Inhibitory Post-Synaptic Potential; neurotransmitter opens ligand-gated channels either letting Cl- into cell or K+ out, causing local hyperpolarization; if strong enough, prevents AP generation at axon hillock
Describe difference between EPSP/IPSP and AP
AP are all-or-nothing, always same strength regardless of strength of stimulus; EPSP/IPSP vary in strength, can be summed, and either encourage or inhibit generation of AP
Define spatial summation
postsynaptic neuron receiving multiple synapse signals from multiple presynaptic neurons simultaneously, causing an additive effect of EPSPs and IPSPs
Define temporal summation
postsynaptic neuron receiving high frequency of APs from same presynaptic neuron, an additive effect sums the EPSP or IPSP
Define synaptic integration
one postsynaptic neuron can be receiving EPSPs and IPSPs at the same time, response of postsynaptic neuron will depend on # of each kind
Name the parts of the motor system
the supplementary motor area, the premotor area, the primary motor cortex, basal ganglia, spinal pathways, motor nerves and muscle receptors
Define motor cortex
located on precentral gyrus, arranged in specific manner (called motor homunculus), activates the neurons that will activate appropriate muscles for movement
Describe the arrangement of the motor homunculus, from medial (midline) to lateral
genitals, foot, ankle, knee, thigh, trunk, shoulder, elbow, wrist, hand, fingers (large area), face, lips (large area), jaw, tongue
Define the corticospinal tract
major motor pathway from primary motor cortex to motor neurons, made of millions of axons whose cell bodies are in primary motor cortex
Describe the path of the corticospinal tract
begins in motor cortex, descends down brain stem, in medulla 80% of nerve fibers cross to contralateral side (20% remain on ipsilateral side), then enter spinal cord to continue descent, reach appropriate level and synapse with motor neurons, remaining fibers cross to contralateral side
Define proprioception
“muscle sense”, brain awareness of the position of limbs and extent of each muscle contraction at all times
Define muscle receptors
proprioception is possible because special receptors send signals back to brain; two types: muscle spindles and golgi tendon organs
Define muscle spindles
sensory organs consisting of intrafusal muscle fiber, central sensory region, two sets of gamma motor neurons and a sensory neuron
Name what muscle spindles and golgi tendon organs detect
muscle spindles: muscle stretch, length, and rate of change of muscle length; golgi tendon organs: muscle tension
Describe alpha-gamma coactivation
both types of neurons required to send info back to brain using muscle spindle; alpha innervates extrafusal muscle fibers, gamma innervates intrafusal; if only extrafusal is activated to contract, no message can be sent to brain for proprioception
Name 3 specific functions of cerebellum
contribute to generation of accurate limb movements, correct ongoing movements, modify strength of some reflexes
Name 7 behaviours influenced by the limbic system
feeding, drinking, pain, motivation, learning, fear/rage, and sexual pleasure
Describe the key function of the limbic system
linking higher thought processes of the brain with more primitive emotional responses, allowing us to respond correctly to changes in our environment
Name 7 major functions of the hypothalamus
temp control, body water regulation, food intake regulation, cardiovascular regulation, circadian clock regulation, coordination of emotional behaviours, control of hormones released from pituitary gland
List the 2 divisions of the autonomic nervous system (ANS)
sympathetic (SYN) and parasympathetic (PSYN)
Describe the pathway of the SYN
nerves exit the spinal cord in thoracic and lumbar (central) regions; preganglionic neurons synapse onto second postganglionic nerve near spinal cord
Describe the pathway of the PSYN
nerves exit at the brain stem and very lower sacral region of spinal cord; preganglionic nerves synapse onto postganglionic nerves very near effector organ
Describe function of the SYN
responsible for activating body functions involved in fight or flight situations
Describe function of the PSYN
responsible for storage and conservation of energy, functions associated with rest and relaxation
Name neurotransmitter released by PSYN postganglionic neuron
always ACh
Name neurotransmitter released by SYN postganglionic neuron
usually norepinephrine (NE) but in some cases ACh
