Biology - Body systems and Nervous system

What are the levels of organization in a multicellular organism, from simplest to most complex?

The levels of organization in a multicellular organism, from simplest to most complex, are: cells, tissues, organs, organ systems, and the organism.

What is the main difference between single-celled and multicellular organisms regarding life processes?

Single-celled organisms carry out all processes alone; multicellular organisms use "division of labor" through specialized cells.

Which body system is responsible for transporting oxygen, nutrients, and hormones throughout the body?

The cardiovascular system is responsible for transporting oxygen, nutrients, and hormones throughout the body via blood circulation.

What are the two main parts of the Nervous System and what do they include?

The two main parts of the nervous system are the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and spinal cord, while the PNS comprises all the nerves that connect the CNS to the rest of the body.

Match the specific receptor type to the stimulus it detects:

• Mechanoreceptor

• Chemoreceptor

• Thermoreceptor

• Photoreceptor

Mechanoreceptor: Movement, sound, pressure, touch.

• Chemoreceptor: Chemicals (e.g., smell, taste, blood pH).

• Thermoreceptor: Temperature (heat/cold).

• Photoreceptor: Light (visible light).

What are the three types of neurons and their functions?

Sensory: Carry info from receptors to the CNS.

• Interneuron: Connect neurons within the CNS and process info.

• Motor: Carry instructions from the CNS to effectors (muscles/glands).

In a neuron, what is the function of the Myelin Sheath and the Dendrites?

The myelin sheath insulates the axon, facilitating faster transmission of electrical impulses, while dendrites receive signals from other neurons and transmit them towards the cell body.

What is the gap between the myelin sheaths on an axon called?

The gap is called the Node of Ranvier.

What is the full "Stimulus-Response Model" flow?

stimulus - receptor - sensory neuron - cns(interneuron) - motor neuron - effector - response

In the stimulus-response model, what is an "Effector"?

An organ or cell that acts in response to a stimulus.

What makes a reflex action different from a conscious action?

Reflexes are fast and automatic because they often go through the spinal cord only, bypassing the brain to save time and protect the body.

What is a "Reflex Arc"?

A simple nerve pathway that allows for a quick response to a stimulus, typically involving a sensory neuron, an interneuron in the spinal cord, and a motor neuron.