Unit 1.2 Flashcards
What is the CNS protected by?
-skull and spinal cord
What is the CNS covered by?
- connective tissue meninges
What is the brain?
- site of thoughts and intelligence
- processes info received and sends messages to body
What is the PNS made of?
- nerves and ganglia
What are nerves
- bundled axons that carry signals to and from the CNS
-extend from brain and spinal cord
How are nerves organized?
- epineurium
-perineurium
-endonerium
What is the epineurium?
connective tissue surrounding outer nerve surface
What is the perineurium?
- connective tissue that surrounds and separates bundles of axons organized into fascicles
What are ganglia?
cluster of neuron cell bodies outside of the CNS along the length of a nerve in the PNS
- localizeed
What are the types of afferent systems?
- somatic sensory
-visceral sensory
Whats an example of a visceral sensory organ?
the heart
Whats and example of a somatic sensory organ?
- eyes, ears, skin
What is the afferent pathway?
- sensory nervous system detects stimuli and transmits info from receptors to the CNS
What is the somatic sensory system?
- sensory input that is consciously perceived from receptors
What is the visceral sensory system?
- sensory input that is not consciously perceived by receptors of blood vessels
and internal organs
What is the efferent sensory system?
- motor nervous system that initiates and transmits info from CNS to effectors
What are the parts of the efferent sensory system?
- somatic motor
- autonomic motor
-sympathetic division - parasympathetic division
What is the autonomic motor system?
- motor output that is not consciously or involuntarily controlled
What are the parts of the efferent system?
-sympathetic
-parasympathetic
What is the somatic motor system?
- motor output that is consciously or voluntarily controlled
What is an example of somatic motor system?
-effector is skeletal muscle
What is the sympathetic division?
-fight, flight, or freeze stress response
What is the parasympathetic division?
- resting and digesting branch
-maintains homeostasis
What is an example of the autonomic motor division?
- cardiac muscle
-smooth muscle - glands
What is a fascicle?
bundle of axons
What nervous system do cranial and vertebral nerves a part of?
-PNS
Are nerves an organ or a cell?
-organ
What are axons bundled by?
- connective tissue layers
Are neurons an organ or a cell?
cells
What are multipolar neurons made of?
- Multiple processes extend directly from the neuron cell body
- multiple dendrites and 1 axon
What type of neuron is the most common?
multipolar
What type of neuron are motor neurons and interneurons?
multipolar
What are bipolar neurons made of?
- 2 processes extending directly from cell body
-1 dendrite and one axon
Where are bipolar neurons found?
- eye retina
-olfactory epithelium of nose
What are unipolar neurons made of?
- 1 process attached to cell body/soma
- forms a t-intersection with the 2 processes (peripheral and central) of 1 long axon
dendrites directly attached to the peripheral process of axon
Where are unipolar neurons found?
- most sensory organs
Which type of neuron are part of ganglion in PNS?
- unipolar neuron
What are anaxonic neurons?
- neurons with no axons
What are anaxonic neurons made of?
- processes are only dendrites that extend from cell body
What are interneurons?
connections between neurons
Where are anaxonic neurons fire?
-only in the CNS
What are the functional classifications of neurons?
- sensory/afferent
- interneurons
-motor/association neuron
What do sensory/afferent neurons do?
- receive somatic and visceral sensory input
- conduct AP signals to the CNS
What structural type of neuron are sensory neurons?
- unipolar
- receptive region and cell body in PNS and azon end in CNS
Where are interneurons found?
-entirely in CNS
What structural type of neurons are interneurons?
- multipolar or anaxonic
What do interneurons do?
- receives signals from sensory neurons and sends signals to motor neurons
What pathway are motor/association neurons a part of?
- efferent pathway
What do motor neurons do?
- conducts motor output from CNS to effectors in the PNS
Where are motor neurons found?
- innervate somatic (skeletal) muscle and autonomic effectors (smooth muscle)
What are motor neurons made of?
multiple neurons
What kind of gaps do electrical synapses have?
- no gap
-has a physical connection
-has a gap junction
-Gap junctions use proteins to create pores for ions
What is an electrical synapse?
- junction between 2 neurons that allows for the two way transmission of electrical signals
What type of synapse is the most common?
- chemical
What kind of gaps do chemical synapses have?
-has synaptic cleft
- no physical connection
How do chemical synapses work?
-Electrical signals get turned into chemical signals (NT)
-presynaptic neurons axon terminal which produces signal in the form of NT
-postsynaptic neuron receives signal as NT and binds to receptor and cause a postsynaptic potential
What do postsynaptic potentials do?
- depolarization or hyperpolarization
What is a pro to chemical synapse?
-allows for variability
-smart
What is a pro to electrical synapses?
-fast (but dumb)
What do excitatory NT do?
-depolarization, makes membrane more positive
What do inhibitory NT do?
-hyperpolarization
-membrane more negative
Why is the resting membrane potential negative?
- at the inside is more negative than the outside
-compares membrane innerface to membrane outerface
What does anterograde transport do?
moves newly synthesized material toward synaptic knob
What do retrograde transporters do?
moves used materials from Axon for breakdown and recycling in the cell body
What causes slow transport?
flow of axoplasm?
Where does slow transport occur?
within the azon
Does slow transport require energy?
no