Question

1. how does each division of the autonomic nervous system act on the body? sympathetic parasympathetic body part/system eyes/pupils heart stomach/digestion bladder genitals module 1.3a the neuron & neural firing: neural communication & the endocrine system 11. what is a neuron? 12. diagram the structure of a neuron, labeling each part and identifying its function. a. dendrite: b. soma: c. axon: d. axon terminals or terminal buttons: e. myelin sheath: f. nodes of ranvier: g. schwann cells: h. glial cells:

Explanation:

1. The sympathetic nervous system activates the body's "fight - or - flight" response. For eyes/pupils, it dilates pupils to improve vision in stressful situations. For the heart, it increases heart rate and contractility to pump more blood. For stomach/digestion, it inhibits digestion to divert energy. For the bladder, it relaxes the bladder wall and contracts the sphincter to prevent urination. For genitals, it can cause vasoconstriction and inhibit sexual function in stress. The parasympathetic nervous system promotes "rest - and - digest" functions. It constricts pupils, slows heart rate, stimulates digestion, contracts the bladder for urination, and promotes sexual arousal and function.
2. A neuron is a specialized cell in the nervous system that transmits electrical and chemical signals. It is the basic unit of the nervous system.

12.
a. Dendrite: Receives signals from other neurons.
b. Soma: Cell body that contains the nucleus and other organelles, integrates incoming signals.
c. Axon: Transmits electrical impulses (action potentials) away from the soma.
d. Axon terminals or Terminal Buttons: Release neurotransmitters to communicate with other neurons or target cells.
e. Myelin sheath: Insulates the axon, speeds up the conduction of electrical impulses.
f. Nodes of Ranvier: Gaps in the myelin sheath where the axon is exposed, facilitate saltatory conduction.
g. Schwann cells: Type of glial cell that forms the myelin sheath in the peripheral nervous system.
h. Glial cells: Supportive cells in the nervous system, provide nutrients, insulation, and help with neural function.

Answer:

1. Sympathetic: eyes/pupils - dilate; heart - increase rate/contractility; stomach/digestion - inhibit; bladder - relax wall/contract sphincter; genitals - vasoconstrict/inhibit function. Parasympathetic: eyes/pupils - constrict; heart - slow rate; stomach/digestion - stimulate; bladder - contract for urination; genitals - promote arousal/function.
2. A specialized cell in the nervous system that transmits electrical and chemical signals.

12.
a. Receives signals from other neurons.
b. Cell body, integrates incoming signals.
c. Transmits electrical impulses away from the soma.
d. Release neurotransmitters.
e. Insulates axon, speeds up impulse conduction.
f. Gaps in myelin sheath, facilitate saltatory conduction.
g. Form myelin sheath in PNS.
h. Supportive cells in the nervous system.