Nervous System Flashcards
What are the amin functions of the nervous system?
Control of body’s environment to maintain homeostasis
Regulation of spinal cord reflexes
Regulation of memory + learning
Voluntary control of movement
What makes up the CNS?
Brain + spinal cord
What is the job of CNS?
Integrative + control centre
What makes up PNS?
Cranial nerves + spinal nerves
What is the job of PNS?
Communication lines between CNS + rest of body
What makes up motor (efferent) division?
Motor nerve fibres
What is the job of motor (efferent) division?
Conducts impulses from CNS to effectors (muscles + glands)
What makes up somatic nervous system?
Somatic nerve (voluntary)
What is the job of somatic nervous system?
Conducts impulses from CNS to skeletal muscles
What makes up autonomic nervous system (ANS)?
Visceral motor (involuntary)
What is the job of autonomic nervous system (ANS)?
Conducts impulses from CNS to cardiac muscles, smooth muscles + glands
What makes up sensory (afferent) division?
Somatic + visceral sensory nerve fibres
What is the job of sensory (afferent) division?
Conduct impulses from receptors to CNS?
What are 2 division of ANS?
Sympathetic
Parasympathetic
What does the sympathetic division do?
Mobilises body system during activity
What does parasympathetic division do?
Conserves energy
promotes “housekeeping” functions during rest
What is the sensory upstream path?
ANS
Sensory (afferent) division
PNS
CNS
What is the motor downstream path?
CNS PNS Motor (efferent) division Somatic + autonomic Sympathetic + parasympathetic
What are the divisions of the motor?
Somatic + autonomic
What is a neuron?
Electrically excitable cell that receives, processes + transmits info through electrical + chemical signals
What is a nerve?
Bundle of fibres that conduct impulses between brain or spinal cord + other part of body. Nerves include fragments of neurons (axons) + non-neuronal cells (neuroglia)
What is the nervous system?
Network of nerve cells + fibres which transmits nerve impulses between pores of body + coordinate them
What are the different types of neurons?
Soma
Dendrite
Axon
What is the soma?
Spherical portion of neuron, containing nucleus
What is the dendrite?
Short branched extension of nerve cell, along which impulses received from other cells at synapses + transmitted to cell body
What is the axon?
Long thread-like part of nerve cell, along which impulses are conducted from cell body to other cells
What is sensory (afferent)?
Input neurons
Where is sensory (afferent) located?
PNS
What is motor (efferent)?
Output neurons
What are inter neurons?
Relay neurons
What do inter neurons do?
Connect sensory + motor neurons to each other
Info processing + decision making
What are neurosecretory cells?
Secrete hormones
Where are neurosecretory cells located?
Hypothalamus, adrenal medulla + thyroid gland
What is a unipolar neuron?
Neurite extends from cell body
Sensory
What is a pseudounipolar neuron?
Dendrites + axons fused in single process
What is a bipolar neuron?
2 neurite extensions
Specialised sensory neuron for transmission of special senses
What is a multipolar neuron?
Possesses single axon + many dendrites
What is an anaxonic neuron?
Axon cannot be differentiated from dendrites
What is glia or neuroglia?
Non-neuronal cells that maintain homeostasis: form myelin + provide support & protection for neurons in CNS + PNS
What are the functions of glia cells?
To surround cells + hold them in place
To supply nutrients + O2 to neurons
To insulate one neuron from another
To destroy pathogens + remove dead neurons
What is macroglia?
Generic term for cells in CNS + PNS
What is microglia?
Tissue-based macrophages