chapter 8 Flashcards
organization of the CNS
- Association or interneurons form a network of communication from one area of the brain to another
- We will look at the brain one area at a time according to embryonic divisions of Forebrain, Midbrain, Hindbrain
CNS is composed of
brain and spinal cord
functions of CNS
- Receives input from sensory neurons and directs activity of motor neurons
- Association neurons integrate sensory information and help direct the appropriate response to maintain homeostasis and respond to the environment.
- Humans are capable of learning and memory adding a layer of modification to our behaviors
Forebrain–>Cerebrum
- higher mental functions
- largest portion of the brain
cerebrum consigns of
- cerebral cortex: outer gray matter of cerebrum
- cerebral hemispheres each divided in lobes
- corpus callousum: bundle of nerves that connects the cortex layers of the left and right hemispheres
functions of temporal lobe
Memory, auditory/visual experiences
-includes motor cortex
functions of parietal lobes
Understanding speech, interpretation, somatesthetic interpretation
-includes somatosensory cortex: Body regions are represented by the largest area depending on the highest density of receptors
functions of the frontal lobe
voluntary motor control of skeletal muscles, higher intellectual processes, etc.
functions of the insula
encoding of memory and integration of sensory information with visceral responses
functions of the occipital lobe
vision and coordination of eye movements
EEG
- Measured by electrodes placed on the scalp
- Measures electrical activity of the extracellular fluid
alpha waves
- record from the parietal and occipital regions for awake person with eyes closed.
- 10-12 cycles/sec for an adult
beta waves
- record from frontal lobe with patterns of evoked activity (visual stimuli & mental activity)
- 13-25 cycles/sec
Theta waves
- recorded from temporal and occipital lobes for sleeping adult or tasks that require attention, sleep deprivation, stress.
- 5-8 cycles/sec for asleep person
Delta waves
- recorded from cerebral cortex during sleep.
- 1-5 cycles/sec
emotions controlled by the limbic system; aggression
areas in the amygdala and hypothalamus
emotions controlled by the limbic system; Fear
amygdala and hypothalamus
emotions controlled by the limbic system; Hunger/satiety
hypothalamus
emotions controlled by the limbic system; sex drive
the whole system
Forebrain: Diencephalon–>Thalamus
- Relay center for sensory info (except smell)
- Allows you to focus on lecture and filter out the other senses bombarding you right now (whispers, writing, etc)
Forebrain: Diencephalon–>Epithalamus
- regulates circadian rhythms and choroid plexus
- Includes the pineal gland
forebrain –>hypothalamus
hypothalamus :
-Influenced by higher brain centers
Master command center for neural and endocrine coordination, regulates pituitary gland
-Key to homeostasis regulation: Controls what you need to survive: eating, drinking, regulation of body temp, etc.
2 hormones produced by the forebrain –>hypothalamus
-ADH and oxytocin
-Transported for release by posterior pituitary
Produce releasing and inhibiting hormones transported and released by anterior pituitary
midbrain functions
Motor control, maintains connections from cerebrum to cerebellum
midbrain; Dopaminergic neurons project to basal nuclei and ____ _____
limbic system
-Those neurons leading to areas of the limbic system, hippocampus, amygdala and areas linking to the reward system are key areas for drug addiction studies.
Dopamine
(a hormone associated with ‘good feelings’) is released in the nucleus accumbens (collection of neurons) after consumption of certain addictive drugs.
Hindbrain 2 structues
Pons and Cerebellum
Hidbrain; pons
sensory and motor tracts from the spinal cord, respiratory control centers
Hindbrain; cerebellum
Controls complex motor skills and coordinates movements, motor learning
Receives info from areas of the body involved in movement: muscles & joints (proprioceptors), skin, eyes
Medulla oblongata vital centers
cardio and respiratory**
medulla oblongata
- All ascending and descending tracts between the brain and spinal cord pass through the medulla.
- Relay sensory info to the medulla and then thalamus
optic nerve
- sensory
- function: vision
- II
Vestibulocochlear Nerve
- sensory
- sensory impulses associated w equilibrium
- sensory impulses associated w hearing
- VII
PNS nerves are what kind of nerves
spinal nerves
all spinal nerves/ PNS nerves separate near the spinal cord into a dorsal root carrying _____ (motor/sensory) fibers and a ventral root carrying _____ (motor/sensory) fibers
- dorsal root carrying sensory
- ventral root carrying motor fibers
31 pairs of spinal nerves from top to bottom
- 8 C-cervical
- 12 T-thoracic
- 5 L-lumbar
- 5 S-sacral
- 1 Coccygeal
reflex arc steps
- Reflex responses to stimuli is a multi-step process.
- A stimulus occurs at the receptor of a sensory neuron. This is sent along the afferent neuron as a nervous impulse and is received by the central nervous system
- The interneuron makes connections to the motor neuron. The motor neuron transmits the impulse to the effector organ.
