Animal Structure and Function: The Nervous System

Practice vocabulary flashcards covering the structure and function of the animal nervous system, focusing on human anatomy, neurophysiology, and comparative zoology.

Nerve Net

A simple nervous system found in Cnidarians, such as Hydra, consisting of individual nerve cells connected to each other in a diffused network.

Ganglia

Clusters of nerve cell bodies found in the nervous systems of complex animals like Planaria, Annelids, and Arthropods.

Central Nervous System (CNS)

The part of the nervous system in chordates that consists of the brain and the spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system consisting of nerves and ganglia located outside of the Central Nervous System.

Cerebrospinal Fluid (CSF)

Fluid found in the brain ventricles and the central canal of the spinal cord that acts as a shock absorber and circulates nutrients, hormones, and waste products.

Meninges

Three layers of connective tissue (dura mater, arachnoid mater, and pia mater) that provide protection to the Central Nervous System.

Cerebrum

The largest part of the human brain, divided into right and left cerebral hemispheres, responsible for sensory processing and voluntary motor control.

Corpus Callosum

A thick mass of white matter that connects the right and left cerebral hemispheres.

Thalamus

The main input center for sensory information going to the cerebrum, responsible for sorting and relaying information to specific cerebral cortex regions.

Hypothalamus

The region of the brain responsible for regulating body temperature, thirst, hunger, sleep-wake cycles, and the autonomic nervous system.

Cerebellum

A part of the hindbrain that coordinates voluntary muscle movements, maintains balance and posture, and helps in learning motor skills.

Medulla Oblongata

The lowest part of the brainstem that controls autonomic homeostatic functions including breathing, heart rate, and reflexes like swallowing and coughing.

Autonomic Nervous System

A component of the Peripheral Nervous System that generally regulates involuntary activities by controlling smooth muscles, cardiac muscles, and glands.

Sympathetic Division

A branch of the autonomic nervous system that prepares the body for energy-consuming or stressful 'fight or flight' situations.

Parasympathetic Division

A branch of the autonomic nervous system that promotes 'rest and digest' activities and returns the body to a calm state.

Resting Potential

The membrane potential of a neuron that is not sending a signal, typically ranging between $-60\,mV$ and $-80\,mV$.

Action Potential

A massive change in membrane voltage triggered by a stimulus reaching a threshold, involving depolarization, repolarization, and hyperpolarization.

Refractory Period

A short time after an action potential during which the neuron is unable to respond to another stimulus due to the inactivation of sodium channels.

Synapse

The junction where a neuron communicates with another cell (neuron, muscle, or gland) across a gap known as the synaptic cleft.

Neurotransmitters

Chemical messengers, such as acetylcholine or dopamine, released from synaptic vesicles to transmit signals across chemical synapses.