9H Science: Nervous and Endocrine Systems

Flashcards covering the stimulus-response model, neurons, neurotransmitters, the endocrine system, and brain anatomy.

A detectable change in the internal or external environment of an organism is known as a __________.

stimulus

Receptors that respond to sunlight and are located in the eye are called __________.

Photoreceptors

The __________ are located in the tongue and nose and respond to chemicals.

Chemoreceptors

The nervous system consists of the brain, spinal cord, sensory organs, and all of the __________ that connect these organs with the rest of the body.

nerves

When the body is relaxed, the __________ nervous system is activated, causing a slower heartbeat and continued digestion.

parasympathetic

The pathway where changes are detected by receptors and communicated to effectors to restore normal conditions is called the __________ model.

stimulus-response

In the stimulus-response model, __________ are typically muscles or glands that receive messages from the central nervous system.

effectors

During a reflex action, the __________ sends two messages at the same time: one to the brain and one to the muscle.

spinal cord

The most basic component of the nervous system is the nerve cell, also called a __________.

neuron

The __________ are parts of a neuron specialized to receive signals from neighboring neurons and carry them to the cell body.

Dendrites

The __________ is a thin, long structure that transmits signals from the cell body to the axon terminal.

Axon

The gap between two neurons is called the __________.

synaptic cleft or synapse

Chemicals stored in __________ are released from one neuron to another to transmit signals across the synapse.

vesicles

The neurotransmitter __________ is involved with feeling reward, learning, and emotion; too little of it is associated with Parkinson's disease.

Dopamine

An imbalance of __________, the main inhibitory neurotransmitter, may contribute to anxiety and tremors if levels are too low.

GABA

Hormones are chemical messengers secreted directly into the __________.

bloodstream

The pancreas secretes __________ to lower blood glucose levels and __________ to raise them.

insulin; glucagon

The __________ gland releases Melatonin, which is involved in daily biological rhythms.

Pineal

The maintenance of a constant internal environment is referred to as __________.

homeostasis

The hormone __________ stimulates uterine contractions during labor, which is an example of a positive feedback mechanism.

oxytocin

__________ is a condition caused by damage to the myelin sheath, which can cause electrical signals to be lost.

Multiple sclerosis

The __________ of the brain is the ultimate control and information processing center, divided into four lobes.

Cerebral Cortex

The __________ lobe is responsible for executive functions, muscle movements, and making plans or judgements.

Frontal

Within the limbic system, the __________ is linked to emotion and fear.

Amygdala

The __________ is a structure that ensures both hemispheres of the brain can communicate.

Corpus Collosum