Lecture 1: Intro to Neuroscience Flashcards
What is the general function of our nervous system?
- control
- regulate
- communicate
What are the components of the CNS?
brain and spinal cord
What are the components of the PNS?
Somatic:
-cranial and spinal nerves
Autonomic:
-Parasympathetic, Sympathetic, Enteric
What are the main components of the neuron?
- dendrites
- soma (cell body)
- axon hillock
- axon
- terminal branches
- synapse
Dendrite function
receives signals
Soma function
- interpret info from dendrite
- determine if there is going to be an AP
- contains nucleus and organelles
Axon hillock function
signal becomes an AP –> elicits response
Axon function
- where the AP travels
- contains Myelin Sheath and Nodes of Ranvier
Terminal branches function
- at the very end right before synapse
- sends out NTs into synapse
Synapse function
specialized point of functional contact between neurons, or between a neuron and a target organ
What are the 3 types of neurons that can be found in the nervous system? Structural and Functional
Structural: -multipolar -bipolar -unipolar Functional: -sensory (afferent) -motor (efferent) -interneuron
Multipolar neuron
most common, several dendrites and axons
Bipolar neuron
rare, single dendrite and single axon arising from a cell body, for special sensory organs (sight and smell)
Unipolar neuron
in PNS, axon and dendrite arise from a single process
arising from a soma
Main role of sensory (afferent) neurons and types
- Afferent= arrive
- signals from receptors to CNS
- special sensory:
i. vision
ii. auditory
iii. equilibrium
iv. gustatory (taste) - viscerosensory: unconscious
- somatosensory: conscious
Main role of motor (efferent) neurons and types
- efferent=exit (response)
- signals from CNS to effectors
- somatomotor: voluntary; CNS–> skeletal muscle
- autonomic motor: involuntary; connects vital structures to CNS; smooth muscle, cardiac glands
What is the function of interneurons/associative neurons?
- local integration center
- comprised of brain and spinal cord
- connect sensory to motor
Define a reflex
- unidirectional rapid, predictable, and involuntary response to a stimulus
- NO cortical involvement
Define a reflex arc
neural pathway that controls a reflex
-sensory receptor –> sensory neuron –> interneuron –> motor neuron –> effector
Types of reflexes in human body
- somatic: skeletal muscle (ex: knee jerk)
- autonomic: smooth muscle, cardiac, and glands (ex: salivary reflex)
Explain the steps of the myotatic reflex, starting from the hit of the hammer to the leg kicking outwards.
- “knee jerk”
- hammer hit → extensor muscle → muscle sensory receptor → sensory neuron/ motor neuron in spinal cord/ interneuron synapse inhibits motor neuron in flexor muscles → motor neuron sends AP to extensor muscle to contract/ flexor relaxes due to inhibition of motor neuron
Explain the steps of the Flexor Withdrawal Reflex. When does this reflex come into play in function?
- flexor reflex + crossed extension reflex
i. flexor reflex: painful stimulus → afferent neuron → interneurons → efferent neurons → excitation of flexors, inhibition of extensors
ii. crossed extension: painful stimulus → afferent neuron → interneurons cross midline → efferent neurons → excitation of extensors, inhibition of flexors
Function of astrocytes and PNS equivalent
-are glial cells
-support cells
-maintain BBB
-tissue repair
-1/2 of CNS neural tissue
PNS equivalent= satellite cells
Function of ependymal cells and where they are found
- they produce and facilitate exchange of CSF
- line ventricle and central canal walls, forming choroid plexus
