The primary functions and mechanisms of the human nervous and endocrine systems, which work together to maintain internal balance.

What is the function of the Nervous system?

The Nervous system coordinates and controls the body's responses to internal and external stimuli, enabling communication between different parts of the body.

What are the three types of neurons and their functions?

1. Sensory Neuron: Transmits sensory information from receptors to the brain and spinal cord.

2. Interneuron: Connects sensory and motor neurons, processing information within the central nervous system.

3. Motor Neuron: Carries signals from the brain and spinal cord to muscles and glands to elicit a response.

What is the structure of a neuron?

A neuron consists of a cell body (soma), dendrites (receive signals), and an axon (sends signals). Key features include the axon terminal, myelin sheath, and node of Ranvier.

What are the functions of the different parts of a neuron?

• Dendrites: Receive signals from other neurons.

• Cell body (soma): Contains the nucleus and processes signals.

• Axon: Transmits electrical impulses away from the cell body.

• Axon terminal: Releases neurotransmitters to communicate with other neurons.

What are the steps of neural transmission between neurons?

1. An electrical impulse travels down the axon to the axon terminal.

2. The impulse triggers the release of neurotransmitters into the synapse.

3. Neurotransmitters bind to receptors on the next neuron, leading to a new electrical impulse.

What is the difference between electrical and chemical messages during neural transmission?

• Electrical messages: Fast signals transmitted along the axon via action potentials.

• Chemical messages: Slower signals transmitted across the synapse using neurotransmitters.

What is a stimulus-response model?

A model that describes how an organism reacts to an external stimulus. For example, touching a hot surface (stimulus) leads to a reflex action of pulling back (response).

What are the major components and features of a reflex action?

A reflex action involves a sensory input, interneurons in the spinal cord, and a motor output that occurs quickly and involuntarily without conscious thought.

What are the three main structures of the brain and their functions?

1. Cerebrum/cerebral cortex: Responsible for higher brain functions such as thought, action, and sensory processing.

2. Cerebellum: Coordinates movement and balance.

3. Brain stem: Controls vital life functions such as breathing and heartbeat.

What is the role of the hypothalamus and pituitary glands in the Endocrine system?

The hypothalamus regulates bodily functions through hormone release, while the pituitary gland secretes hormones that control various bodily functions including growth and metabolism.

What steps do hormones take to act on a target cell?

1. Hormones are released into the bloodstream.

2. They travel to target cells with specific receptors.

3. Hormones bind to receptors, triggering a cellular response.

What are the similarities and differences between the nervous and endocrine systems?

• Similarities: Both systems control and coordinate body functions.

• Differences: The nervous system uses electrical impulses for rapid responses, while the endocrine system uses hormones for slower, long-lasting effects.

What is homeostasis?

Homeostasis is the process by which the body maintains a stable internal environment despite changes in external conditions.

How does the body maintain homeostasis via feedback systems?

Homeostasis is maintained through negative feedback (corrects deviations from a set point) and positive feedback (enhances a process) systems.