Ch 12 Nervous System Flashcards
The order of the nervous system
Stimulus -> Sensory receptor -> Sensory neuron -> CNS -> Motor neuron -> effector
What is considered the thermoreceptor?
Sensory receptors and sensory neurons
What does the PNS do?
Collects info and afferent
What does the PNS do?
Output and efferent
What is in the CNS?
Brain and spinal cord
What does the CNS do?
Integrate
What are the 4 types of effectors?
Skeletal muscle, smooth muscle, cardiac muscle, glands
What’s in the PNS in the system?
Sensory receptor, sensory neuron, motor neuron and effector
What’s is the PNS made of?
Nerves and ganglia
Bundles of axon
Nerves
Clusters of cell bodies
Ganglia
Sensory nervous system =
Afferent nervous system
What does sensory nervous system do?
Receives sensory information
What is somatic sensory system?
Hearing, vision, touching
What is visceral sensory system?
Smooth muscle, cardiac muscle, glands
Motor nervous system =
Efferent nervous system
What muscle is the motor nervous system?
Skeletal muscle
What is somatic motor system?
Sends voluntary signals to skeletal muscles
What is autonomic motor system?
Sends involuntary commands to heart, smooth muscle, and glands
What is in the ANS?
Sympathetic and parasympathetic
What is sympathetic?
Fight or flight and stressor occurring
What is parasympathetic?
Rest and digest and controls homeostasis
What tissue is epineurium?
Dense irregular connective tissue
What tissue is perineurium?
Dense irregular connective tissue
What tissue is endoneurium?
Areolar connective tissue
What does epineurium nerve do?
Encloses entire nerve
What does perineurium nerve do?
Wraps fascicle
What is fascicle?
Smaller group of bundles of axons in nerve
What does endoneurium nerve do?
Supports neuron and wraps an individual axon
Two types of nerves
Cranial and spinal
Classification nerves for function
Sensory, motor, mixed nerves
What is excitability?
Responsiveness to a stimulus
What is the start of a neuron?
Excitability
What is conductivity?
Propagate electrical signal; actin potential in axon
What is secretion?
Release a neurotransmitter in response to conductive activity
What is extreme longevity?
How long cells live and same neurons since birth
What is amitotic?
Mitotic activity is lost in most neurons
What is the point of the cell body?
Dumping a lot of ions to create an action potential
What is chromatophilic substance made of?
Ribosomes
What does dendrites receive?
Receive information and transfers to cell body
What is the axon?
Long process emanating from cell body
What is axon hillock?
Attaches to cell body
What is axoplasm?
Cytoplasm of the axon
What is axolemma?
Membrane of the axon
What are axon collaterals?
Splits into branches
What does the axon end with?
Axon terminal
What do synaptic vesicles do?
Have neurotransmitters that talk to the next cell
What is the function of axons?
To conduct action potential
What is the cytoplasm composed of?
Microfilaments, intermediate filaments, microtubules
What is neurofibrils?
Form bundles and provide strength
What is retrograde transport?
To cell body
What is anterograde transport?
From cell body
What is fast axonal transport?
Movement along microtubules and powered by ATP
What is slow axonal transport?
Moved from cell body to knob and is for replacing things
Multipolar neurons
Many dendrites and one axon
Bipolar neurons
One dendrite and one axon
Unipolar neurons
One process extends from cell body
Where are interneurons located?
Within CNS
What is synapse?
Neurons connect to another neuron or effector
What is electrical synapse ?
Presynaptic and postsynaptic neurons bound together by gap junctions
What must happen in chemical synapse?
Has to diffuse and initiates action potential
What is presynaptic neurons?
Axon terminal produces signal
What is postsynaptic neurons?
Receives the signal
What is synaptic cleft?
Space in between pre and post synaptic neurons
What is glial cells?
Non excitable, support cells found in CNS and PNS
What is astrocytes?
Help form blood-brain barrier by wrapping feet around brain capillaries
What does blood-brain barrier control?
Which substances have access to brain
What is ependymal cells?
Line cavities in brain and spinal cord
What is microglia?
CNS and immune system for brain
What is oligodendrocytes?
Slender extension forms myelin sheath
What are satellite cells?
Insulate and regulate the exchange of nutrients and waste; PNS
What are Schwann cells?
PNS axons with myelin and cause a faster action potential
Neoplasm from unregulated cell growth and supporting tissues
Tumors
What is myelination?
Process of wrapping an axon with myelin
How many axon can Schwann cells myelinate?
1 mm
What is nodes of Ranvier?
Gaps between Schwann cells
Myelination by oligodendrocytes
In CNS, one oligodendrocyte and myelinate 1 mm of multiple axons
Unmyelinated axons in PNS
Axon sits not fully covered
Unmyelinated axons in CNS
Axons not associated with oligodendrocytes