Ch. 10 - Neurophysiology Flashcards
What are the right and left cerebral hemispheres connected by?
The corpus callosum
What are the 4 lobes per hemisphere of the brain?
- Frontal
- Parietal
- Occipital
- Temporal
What are the functions of the lobes?
- Frontal - control skilled motor behavior
- Parietal - interpret somatosensory input
- Occipital - interpret visual stimuli
- Temporal - interpret auditory input
What makes up the diencephalon?
The thalamus and hypothalamus
Describe the thalamus.
- Ovoid mass of gray matter
- Ascending stimuli (all sensory except olfactory) is relayed through the thalamus to cerebral cortex
What part of the brain controls the homeostatic processes and is often associated with autonomic nervous system?
Hypothalamus
Describe the hypothalamus.
- Collection of nerve cells
- Lies subcortical (at base of cerebrum)
What does the hypothalamus regulate?
- Body temperature
- Appetite
- Water balance (Thirst)
- Sexual activity
- Sleep
- Emotions
- Pituitary secretions
- Autonomic functions - GI & cardiac activity
What controlls the bodies heat regulation?
Posterior hypothalamus
What is the most potent mechanism for heat production, and what does it cause?
Shivering - causes fibrillation of muscle for heat production
What are the different ways of heat transer?
- Heat transfer - emission of heat in form of infrared rays
- Conduction - flow of heat energy from warmer to cooler environment (down gradient)
- Convection - movement of heat by currents in the medium (ex wind)
- Evaporation - conversion of a liquid into vapor (respiratory, skin, sweating)
What does the Limbic system consist of?
The hippocampus & amygdala
Where is the limbic system located?
Deep in the temporal lobe - primitive brain area
What basic drives does the limbic system initiate?
- Hunger
- Aggression
- Emotional feelings
- Sexual arousal
What part of the brain functions in learning and memory?
Hippocampus
What part of the limbic system is the center of emotions?
Amygdala
(Communicated with the autonomic system)
Oxytocin and ADH receptors
What is located deep to the cerebral cortex and controls complex patterns of voluntary motor behavior (inhibitory)?
Basal Ganglia
What does the Basal Ganglia include?
- Caudate nucleus
- Putamen
- Globus pallidus
- Substantia nigra
- Subthalamic nucleus
Where does the cerebellum lie?
Posteroinferior to cerebrum, superposterior to brain stem
What are the functions of the cerebellum?
Excitatory functions
- Maintains muscle tone
- Coordinates muscle movement
- Controls balance
How does the output of the cerebellum relate to the output of the basal ganglia?
Cerebellum - excitatory
Basal ganglia - inhibitory
What is the motor pathway?
- Motor cortex (precentral gyrus) –>
- Upper motor neuron –>
- Internal capsule –>
- Corticospinal tract –>
- (Cerebral peduncles - midbrain) –>
- (Pyramids - medulla - fibers cross) –>
- Ventral horn (spinal cord) –>
- Lower motor neuron –>
- Muscle
What lies immediately inferior to the cerebrum and just anterior to the cerebellum?
The Brain Stem
What does the brain stem consist of?
Midbrain, Pons, Medulla
What nuclei are located in the midbrain (mesencephalon)?
CN III, IV
along with substantia nigra
What cranial nerve nuclei are found in the Pons?
- V
- VI
- VII
- VIII
5,6,7,8
What is the most inferior segment of the vertebrate brain?
Medulla Oblongata
What important regulatory centers does the medulla oblongata contain?
- Area postrema - vomiting
- Swallowing
- Cardiac
- Vasomotor
- Respiratory
What cranial nerve nuclei are found in the medulla oblongata?
CN: 9,10,11,12
- IX
- X
- XI
- XII
What are the subdivisions of the Peripheral Nervous System?
- Somatic Nervous System
- Autonomic Nervous System
- Sympathetic
- Parasympathetic
How many pairs of cranial nerves and spinal nerves are there in the somatic nervous system?
- 12 pairs of ranial nerves
- 31 pairs of spinal nerves
What is a key difference with the synapses of Motor vs Sensory?
- Motor
- No synapse in peripheral region
- Uses 1 efferent neuron from the CNS to end-organ (LMN)
- Sensory
- Synapse within dorsal root ganglion (peripheral) prior to CNS
Parasympathetic postganlgionic neurons are _________ where sympathetic postganglionic neurons are largely _________.
- Cholinergic
- Adrenergic
What is the basic anatomic pathway of the autonomic nervous system?
- Preganglionic neuron (within CNS)
- Ganglion (cell bodies of postganglionic neurons, outside the CNS)
- Postganglionic neuron (outside CNS)
- Effector organ
