Homeostasis, Nervous System, and Endocrine Functions

Homeostasis

Stability of internal body conditions despite external changes.

Feedback loops

Mechanisms that maintain homeostasis through responses.

Negative feedback loop

Reverses changes to restore normal conditions.

Positive feedback loop

Increases changes to amplify a process.

Central Nervous System (CNS)

Includes brain and spinal cord for processing information.

Peripheral Nervous System (PNS)

Nerves outside CNS that transmit messages.

Sensory neurons

Carry messages from receptors to CNS.

Motor neurons

Transmit messages from CNS to muscles or glands.

Interneurons

Connect sensory and motor neurons within CNS.

Synapse

Gap between neurons for signal transmission.

Neurotransmitter

Chemical that transmits signals across synapse.

Dendrites

Receive messages from other neurons.

Cell body

Contains nucleus and organelles of neuron.

Nucleus

Controls activities of the neuron.

Axon

Carries messages away from the neuron.

Myelin sheath

Insulates axon to speed up messages.

Stimulus-Response Model

Explains body's reaction to environmental changes.

Reflex

Fast, automatic response bypassing the brain.

Reflex arc

Pathway of a reflex action.

Hormone

Chemical messenger regulating body functions.

Endocrine glands

Glands producing hormones for bodily regulation.

Lock-and-key model

Hormones fit specific receptors to trigger responses.

Pituitary gland

Master gland controlling other glands' functions.

Blood sugar homeostasis

Regulation of blood glucose levels by hormones.

Diabetes

Condition of improper blood sugar regulation.