Intro to Neural Tissue/NS (Quiz 1) Flashcards
What are the organs of the nervous system?
-brain and spinal cord
-sensory receptors of sense organs like eyes and ears
-nerves connect NS with other systems
If a neuron does not depolarize to threshold then….
there is no AP
If a neuron does not release neurotransmitters then….
there is no continued propagation of info
Where and who a neuron communicates with determines our ___________, and controls how we process and coordinate the response
perception
What are the anatomical divisions of the nervous system?
1) CNS
2) PNS
What does the CNS consist of and what does it contain?
-consists of the spinal cord and brain
-contains neural tissue, connective tissue, and blood vessels
What are the functions of the CNS?
process and coordinate, more specifically:
-process sensory data from inside and outside of body
-coordinate motor commands and control activities of peripheral organs like skeletal muscles
-control and regulate high functions of the brain like intelligence, memory, learning, and emotion
sensory= info in
motor= info out
What makes up the PNS?
all neural tissue outside of the CNS
What is the main component of the PNS?
nerves
What are the functions of the PNS?
-deliver sensory info TO the CNS (afferent)
-carry motor commands TO peripheral tissues/systems from the CNS (efferent)
T/F: there are nerves in the brain
FALSE
What do nerves contain and what do they carry?
-contain bundles of axons (myelinated or unmyelinated) with connective tissues and blood vessels
-carry sensory info and motor commands in PNS through cranial and spinal nerves
Cranial nerves connect to….
brain (theres 12 pairs of cranial nerves)
Spinal nerves connect to….
spinal cord (theres 31 pairs and plexuses of spinal nerves)
Which axons are fast? Which are slow?
big axons= fast
smaller= slower
myelin also helps with speed
Bigger axons have more room for voltage gated sodium channels which helps with speed!
What are the characteristics of afferent neurons?
-info goes from the PNS to the CNS
-input goes to the brainstem or spinal cord
-it is sensory info about something
-info goes “in” or “to”
What are the characteristics of efferent neurons?
-info goes from CNS to PNS
-info leaves brain or spinal cord
-info goes from CNS to target tissue
-it is motor info to do something like contract or secrete
What does SAME mean (its a mnemonic)?
SA= sensory afferent
ME= motor efferent
Afferent and efferent transmission is used to describe….
bundles of axons in the PNS, known as nerves
T/F: peripheral nerves can contain axons of different classifications
true
What are the functional divisions of the afferent division of PNS?
receptors and effectors
What are receptors in regards to afferent division of PNS? What are the characteristics of receptors?
-1st part of neuron
-can detect changes or respond to stimuli
-its neurons and specialized cells or complex sensory organs like eyes and ears
What are effectors in regards to afferent division of PNS? What are the characteristics of effectors?
-they respond to efferent signals and have a response
-effectors are cells, organs, and glands
What are the efferent divisions of the PNS?
1) somatic NS (SNS)
2) autonomic NS (ANS)
Which NS controls skeletal muscle contractions, both voluntary and involuntary (reflex) muscle contractions, and is consciously aware of the contraction?
Somatic NS (SNS)
Which NS controls subconscious actions (involuntary) contractions of smooth muscle, cardiac muscle, and glandular secretions?
Autonomic NS (ANS)
Which NS divides into sympathetic and parasympathetic divisions?
Autonomic NS (ANS)
Which NS has dual innervation?
Autonomic NS (ANS has sympathetic and parasympathetic division)
The sympathetic division of the ANS has a _______________ effect
Stimulating
The parasympathetic division of the ANS has a ____________ effect
Relaxing
T/F: nervous tissue is only found in the nervous system
True
What are the cells of the NS?
Neurons and neuroglia
__________ are the basic functional units of the NS and have information processing and signaling roles
Neurons
Information transmitted throughout the body is a combination of action potentials- ___________ activity and neurotransmission via neurotransmitters- ____________ activity
electrical, chemical
What part of the neuron contains the nucleus and organelles, and is covered in dendrites?
soma/cell body
What is the name for RER in neurons?
Nissl substance (note: the function is still to make proteins, but in this case its specifically neurotransmitters)
What part of the neuron has dense/dark areas of RER and ribosomes and makes the neural tissue appear gray (gray matter)?
Nissl bodies/substance
What are dendrites? What are the characteristics?
-highly branched and have many dendritic spines
-they receive info from other neurons
-so more dendrites= more info
-they take up 80-90% of neuron SA