Lecture 2: How Does Nervous System Function Flashcards
What two systems make up the nervous system?
The central nervous system (CNS) and the peripheral nervous system (PNS)
The CNS is composed of what two major units?
The brain and spinal cord
What two systems make up the peripheral nervous system?
The somatic nervous system and the autonomic nervous system
What types of nerves are in the somatic nervous system?
Cranial and spinal
What does the somatic nervous system do?
Transmit sensation and produce movement
What does the autonomic nervous system do?
Balances internal functions
What are the two divisions of the autonomic nervous system?
Sympathetic and parasympathetic
What does the sympathetic nervous system do?
Arousal - fight or flight
What does the parasympathetic nervous system do?
Calming - rest and digest
Name the three meninges in order from outside to inside
Dura mater
Arachnoid layer
Pia mater
What is the cerebrum divided into
Two hemispheres
What are the functions of the cerebellum?
Control and coordination of motor skills
What is the function of the brain stem?
Unconscious behaviours of the body - breathing, heart rate, bodily functions.
What are gyri and sulci?
Bumps and cracks on cerebral cortex that increase its surface area
What is the composition of grey matter, and its purpose
Cell bodies and capillary blood vessels. Functions to process info and support behaviour
What is the composition of white matter and its purpose
Nerve fibres and their fatty coverings (axons) and functions to connect cells
What are the ventricles
4 cavalries in the brain filled with CSF. The right and left lateral ventricles, the third and fourth.
What is the corpus callosum
“Bridge” that connects two hemispheres made of nerve fibres.
What are two major cell types
Neuron and glial
What is the function of a neuron
Carry out major brain functions
What is the function of glial cells
Aid and modulate neuron activity. Like moms.
What types of nerves does the brain stem mediate
Afferent nerves coming into brain from body’s sensation organs, efferent nerves exiting the brain sending signals through spinal cord
What are the three main regions of the brain stem
Hindbrain
Midbrain
Diencephalon
What are the three components of the hindbrain
Cerebellum
Reticular formation
Pons
What are the two parts of the midbrain
The tectum (receives info from eyes and ears, production of oriented movements) and the tegmentum (initiates movement, sexual behaviour, movement of limbs)
What two units compose the diencephalon
Hypothalamus
Thalamus
Purpose of the hypothalamus
Control hormone production via pituitary gland
Function of the thalamus
All sensory info comes into thalamus, then goes into cortex
Three components of forebrain
Neocortex
Basal ganglia
Limbic system
What are the three components of the forebrain?
Neocortex
Limbic system
Basal ganglia
Function of the neocortex
6 layers of gray matter that respond to perceptual world
Function of the limbus system
3-4 layers of gray matter which control motivational and emotional states
Describe neocortex functions at different levels of gray matter
Top layers: integrative functions
Middle layers: afferent nerves bring in sensory input
Bottom layers: efferent nerves sending out directives
Each layer has a different neuron cell type
List the four lobes and their functions
Frontal: executive function and motor control
Occipital : vision
Parietal: tactile function
Temporal: auditory, visual, gustatory
Describe the purpose and structures of the basal ganglia
Purpose: controls certain aspects of voluntary movements
Parts: caudate nucleus, putamen, globus pallidus
List parts of limbic system
Limbic cortex
Amygdala
Hippocampus
What is the function of the limbic cortex?
Certain aspects of memory
What is the function of the hippocampus
Memory storage, especially spatial memory
What is the function of the amygdala?
Negative emotions, fearful memories, fear acquisition
Describe the olfactory system
A structure in the forebrain, olfactory bulb receives input from nose and sends to pyriform cortex.
List the 12 cranial nerves
OLd OPen OCeans TROble TRIbesmen ABout Fish VEnom Giving VArious SPlitting Headaches
Olfactory - smell Optic - vision Oculomotor - eye movement Trochlear - eye movement Trigeminal - chewing and facial sensation Abducens - eye movement Facial - facial movement and sensation vestibular - hearing and balance Glossopharyngeal - tongue and pharynx Vagus - heart, blood vessels, viscera, larynx+ Spinal accessory - neck muscles Hypoglossal - tongue
List the five regions of the spinal column
Cervical 8
Thoracic 12
Lumbar 5
Sacral 5
Define dermatomes
Segments of the body which house nerves (sensory and motor) correlating to the vertebrae of origin (dermatome S2 correlates to nerves exiting the spinal column at the second sacral vertebrae)
Describe how signals are transmitted via spinal nerves
- Sensory receptors activate sensory neurons and enter column via dorsal root
- Branches of these neurons may cross to opposite side of column to transmit via white matter fibre tracts
- Signals descending exit via ventral root to stimulate motor neurons
What is Bell and Magendie’s law?
Dorsal spinal cord is sensory and ventral spinal cord is motor. Allows us to make inferences where damage may have occurred based on sensation and movement in a patient
Describe the sympathetic division of the ANS
“Fight or flight”
Nerves connect to thoracic and lumbar sections of spinal cord
Describe parasympathetic division of ANS
“Rest and digest”
Connects to oculomotor nerve, vagus nerve, and facial nerve. Connected to sacral region of spinal cord
