Human Endocrine and Nervous System Functions

The Endocrine System

Why do we need the endocrine system?

The endocrine system functions to secrete hormones directly into the circulatory system to be carried towards distant target organs. These hormones are transported by the circulatory system to regulate physiology and behavior.

What is the endocrine system made of?

It is composed of various organs and glands.

What do glands need to secrete hormones?

These glands secrete hormones to regulate many bodily functions, including growth and metabolism.

How is hormone secretion controlled?

Once the stimulus is over, the secretion of hormones ends. This is controlled through:

• Feedback mechanisms
• Other glands

Main Glands and the Hormones They Secrete

• Pineal Gland: Melatonin
• Pituitary Gland: ACTH
• Thyroid Gland: TSH
• Thymus: Secretes thymosin
• Adrenal Gland: Adrenaline
• Pancreas: Insulin
• Ovary: Progesterone and estrogen
• Testis: Release testosterone

Pathologies Related to Hormone Concentration

• Diabetes: Related to insulin levels
• Thyroid disorders
• Adrenal insufficiency

The Nervous System

What is the relation and coordination function?

To produce a response, the body requires coordination.

Systems Involved in Relation and Coordination

The systems that take part in these functions and their components are:

• Endocrine system: Made of glands and hormones.
• Nervous system: Receptors, brain, the spinal cord, the locomotor system, muscles, and skeleton.

What is a neuron?

A neuron is an electrically excitable cell that processes and transmits information through electrical and chemical signals.

Types of Neurons

• Sensory Neuron: They carry information from the receptors to the central nervous system.
• Interneuron: They are part of the central nervous system; they connect sensory neurons and motor neurons.
• Motor Neuron: They carry information to the effectors.

How Synapse Occurs

A synapse is a gap between neurons because they don't touch each other. To send information, the presynaptic neuron releases a chemical substance called a neurotransmitter that the postsynaptic neuron collects, producing communication. A single neuron can make many synapses.

Central vs. Peripheral Nervous System

• CNS (Central Nervous System): Consists of the brain and spinal cord.
• PNS (Peripheral Nervous System): Consists of all nerves around the body.

How the Five Senses Work

Sensory information is transmitted from the peripheral nervous system. It travels from the sensory nerves (called receptors) to the spinal cord.