Neurotransmitters cross the synaptic cleft to cause a change in the excitability of the downstream neuron. Acetylcholine is an excitatory neurotransmitter matching the description in the question stem. GABA is an inhibitory neurotransmitter and serotonin is responsible for feelings of happiness. Cortisol and epinephrine are hormones, not neurotransmitters, thus they are released into the bloodstream, not the synaptic cleft.

Neurotransmitters cross the synaptic cleft to cause a change in the excitability of the downstream neuron. Acetylcholine is an excitatory neurotransmitter matching the description in the question stem. GABA is an inhibitory neurotransmitter and serotonin is responsible for feelings of happiness. Cortisol and epinephrine are hormones, not neurotransmitters, thus they are released into the bloodstream, not the synaptic cleft.

Repolarization is one of the last steps of an action potential, where the cell potential of the neuron is made to be negative in value once again. This step is accomplished by the opening of voltage-gated potassium channels, which allows for potassium to exit the neuron.

Repolarization is one of the last steps of an action potential, where the cell potential of the neuron is made to be negative in value once again. This step is accomplished by the opening of voltage-gated potassium channels, which allows for potassium to exit the neuron.

The cerebellum is found in the posterior portion of the brain and controls balance and coordination. The cerebrum controls upper level cognition, such as conscious thought, and memory. The hypothalamus is a crucial endocrine structure and helps regulate hormone secretion from the pituitary and body homeostasis. The brain stem controls the most basic duties of the body, which include breathing rate, heart rate, and blood pressure.

The cerebellum is found in the posterior portion of the brain and controls balance and coordination. The cerebrum controls upper level cognition, such as conscious thought, and memory. The hypothalamus is a crucial endocrine structure and helps regulate hormone secretion from the pituitary and body homeostasis. The brain stem controls the most basic duties of the body, which include breathing rate, heart rate, and blood pressure.

The neuron has three major portions: the dendrites, the cell body, and the axon. The dendrites receive electrical stimulation from other neurons, and the axon sends electrical signals to other neurons.

Signals travel down the axon until they reach the axon terminal. Vesicles of neurotransmitter are released from the axon terminal, where they travel across the synapse to the dendrite of the post-synaptic neuron. This initiates a signal in the dendrite, which is carried to the cell body. Signals from different dendrites sum together in the axon hillock, which can stimulate depolarization of the axon and allow for signal propagation.

The neuron has three major portions: the dendrites, the cell body, and the axon. The dendrites receive electrical stimulation from other neurons, and the axon sends electrical signals to other neurons.

Signals travel down the axon until they reach the axon terminal. Vesicles of neurotransmitter are released from the axon terminal, where they travel across the synapse to the dendrite of the post-synaptic neuron. This initiates a signal in the dendrite, which is carried to the cell body. Signals from different dendrites sum together in the axon hillock, which can stimulate depolarization of the axon and allow for signal propagation.

Digestion and excretion are not consciously controlled, which means that they fall under the control of the autonomic nervous system. The autonomic nervous system has two branches: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is involved in "fight or flight" activities, while the parasympathetic nervous system controls "rest and digest" activities. As a result, digestive and excretory activity is increased by the parasympathetic nervous system.

The central nervous system contain components of both the sympathetic and parasympathetic nervous system and controls a variety of nervous functions. Only the brain and spinal cord are considered part of the central nervous system. The somatic nervous system is under voluntary control, and is primarily linked to skeletal muscle.

Digestion and excretion are not consciously controlled, which means that they fall under the control of the autonomic nervous system. The autonomic nervous system has two branches: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system is involved in "fight or flight" activities, while the parasympathetic nervous system controls "rest and digest" activities. As a result, digestive and excretory activity is increased by the parasympathetic nervous system.

The central nervous system contain components of both the sympathetic and parasympathetic nervous system and controls a variety of nervous functions. Only the brain and spinal cord are considered part of the central nervous system. The somatic nervous system is under voluntary control, and is primarily linked to skeletal muscle.