Week 4 Neurological Functions: chapters 16, 17, 18 & 19
Central Nervous System- Brain & spinal cord
I. Brain
* Ability to reason, function
... [Show More] intellectually, express personality & mood, perceive & interact with the environment
A. Forebrain (telencephalon: cerebral hemispheres & diencephalon: interbrain)
a. Cerebral cortex (largest portion of the brain)
b. Basal ganglia (several nuclei)
c. Cerebral cortex: outer layer of neurons (grey matter) that receive, integrate, store & transmit info & white matter (beneath the cerebral cortex) composed of myelinated nerve fibers
Telencephalon
Frontal lobe (central sulcus): future planning, self-management, decision-making
* Speech & language issues (Broca’s area: helps put thoughts into words), ability to speak, understand language, produce speech aka aphasia & dysphagia
* Motor skills (primary motor cortex) such as coordinate voluntary movements (walking & running)
* Comparing objects
* Forming memories (long-term)
* Empathy
* Personality
* Reward-seeking behavior & motivation (dopamine-sensitive neurons)
* Attention, selective attention
Parietal lobe: somatic sensory input (storage, analysis, interpretation of sensory stimuli)
* Touch, temperature, vibratory sense
* Hemiplegia
* Differentiate between right & left
* Difficulty with reading, writing & math
* Apraxia
Occipital lobe: primary visual cortex
* Homonomous hemianopia
Temporal lobe: primary auditory cortex
* Receptive aphasia or dysphagia (Wernicke’s area: sensory speech, responsible for reception & interpretation of speech
* Memory consolidating issues
* Hearing: auditory agnosia, verbal agnosia, illusions & hallucinations
* Memory, emotion & behavior: loss of short & long term memory, aggressive behavior, lack of interest (depression)
* Seizures, vertigo, abnormal perception of time, disturbances of smell & taste
Corpus callosum: bundle of myelinated fibers that connects the two cerebral hemispheres
Basal ganglia (contains substantia nigra): coordination of voluntary movements, cognitive & emotional function
Extrapyramidal system: motor control system that causes involuntary reflexes, has a stabilizing effect on motor control
Limbic System (group of interconnected structures located between the telencephalon & diencephalon): mediates emotion, long-term memory, behavioral responses, visceral reaction to emotion, motivation, mood, feeding behaviors, biologic rhythms, sense of smell
Amygdala
Hippocampus
Fornix
Hypothalamus
Diencephalon
Thalamus: major integrating system for afferent (sensory) stimuli to the cerebral cortex
* Relay center for info from basal ganglia & cerebellum to the appropriate motor area
* Cortical processing for interpretation
Hypothalamus: maintain constant internal environment & implement behavioral patterns
* Autonomic (sympathetic & parasympathetic NS) nervous system function, regulate body temperature, endocrine function- hormone synthesis, adjust emotional expression
B. Midbrain
Superior colliculi: voluntary & involuntary visual motor movements (eyes to track moving objects)
Inferior colliculi: similar motor activities; involve movements affecting the auditory system
Tegmentum (composed of the red nucleus & substantia nigra): Red nucleus- receives ascending sensory info from the cerebellum, substantia nigra- synthesizes dopamine (PD)
C. Hindbrain (metencephalon & myelencephalon)
Metencephalon
Cerebellum: two lobes; reflexive, involuntary fine-tuning of motor control, maintaining balance & posture through extensive neural connections with the medulla
* Ipsilateral (same side) control of the body (contrast to cerebral cortex)
Pons: transmits info from the cerebellum to the brainstem between the two cerebellar hemispheres
* Nuclei of the 5th to the 8th cranial nerves
Myelencephalon (Medulla oblongata)
Lowest portion of brainstem
*
* Reflex activities such as HR, RR, BP, coughing, sneezing, swallowing & vomiting
* Nuclei of cranial nerves 9th to 12th
II. Spinal cord
* Transmit long motor & sensory tracts that originate in the brain and synapse with cell bodies in gray matter of the spinal cord before exiting to the body
* Somatic & autonomic reflexes, motor pattern control centers, sensory & motor modulation
* Divided into sections: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral & 1 coccygeal
Peripheral Nervous System
* Nerves outside the CNS
* Somatic NS controls voluntary muscle movement (efferent nerves) and sensory info (afferent nerves)
* Cranial & spinal nerves
Autonomic Nervous System
* Regulates involuntary function of internal organs
* Part of the efferent division of the PNS
* Separated by two divisions: sympathetic nervous system & parasympathetic nervous system
Parasympathetic & Sympathetic NS
Body organs are innervated by these two nervous systems
The two divisions cause opposite responses
(Ex: sympathetic stimulation of the GI tract causes peristalsis, whereas parasympathetic stimulation peristalsis)
Release acetylcholine via cholinergic transmission [Show Less]