Control and Coordination in Biology

Consists of Central Nervous System (CNS) and Peripheral Nervous System (PNS)
CNS: Brain and Spinal Cord; integrates and processes information
PNS: Nerves that connect CNS to rest of the body; transmits and receives information
Functions:
- Controls and coordinates body functions
- Interprets and responds to stimuli
- Enables learning and memory

Automatic responses to stimuli
Do not involve conscious thought
Examples:
- Withdrawal of hand from hot surface
- Blinking when something approaches the eye
Components:
- Receptor: detects stimulus
- Sensory neuron: transmits signal to CNS
- Motor neuron: transmits signal from CNS to effector
- Effector: responds to stimulus (e.g. muscle contraction)

Specialized cells that detect stimuli
Types:
- Photoreceptors: respond to light (e.g. eyes)
- Thermoreceptors: respond to temperature (e.g. skin)
- Mechanoreceptors: respond to touch, pressure, and vibration (e.g. skin, ears)
- Chemoreceptors: respond to chemicals (e.g. taste buds, nose)
Function:
- Convert stimuli into electrical signals that can be interpreted by the CNS

Conscious, intentional movements
Involve the CNS and PNS
Examples:
- Walking
- Writing
- Speaking
Components:
- Cerebrum: integrates information and sends signals to motor neurons
- Motor neurons: transmit signals to muscles
- Muscles: contract to produce movement

System of glands that produce and secrete hormones
Hormones: chemical messengers that regulate various body functions
Examples of endocrine glands:
- Pituitary gland
- Thyroid gland
- Adrenal glands
- Pancreas
Functions:
- Regulates growth and development
- Controls metabolic rate
- Regulates electrolyte and water balance
- Helps respond to stress

The Nervous System consists of two main parts: Central Nervous System (CNS) and Peripheral Nervous System (PNS)
CNS is composed of the Brain and Spinal Cord, and is responsible for integrating and processing information
PNS is composed of nerves that connect CNS to the rest of the body, and transmits and receives information
The Nervous System has three main functions: controlling and coordinating body functions, interpreting and responding to stimuli, and enabling learning and memory

Reflex actions are automatic responses to stimuli that do not involve conscious thought
Examples of reflex actions include withdrawing a hand from a hot surface and blinking when something approaches the eye
The components of a reflex action are: receptor, sensory neuron, motor neuron, and effector

Sensory receptors are specialized cells that detect stimuli and convert them into electrical signals that can be interpreted by the CNS
There are four main types of sensory receptors: photoreceptors, thermoreceptors, mechanoreceptors, and chemoreceptors
Examples of sensory receptors include eyes, skin, ears, taste buds, and nose

Voluntary movements are conscious, intentional movements that involve the CNS and PNS
Examples of voluntary movements include walking, writing, and speaking
The components of a voluntary movement are: cerebrum, motor neurons, and muscles

The Endocrine System is a system of glands that produce and secrete hormones
Hormones are chemical messengers that regulate various body functions
Examples of endocrine glands include the pituitary gland, thyroid gland, adrenal glands, and pancreas
The Endocrine System has several functions, including regulating growth and development, controlling metabolic rate, regulating electrolyte and water balance, and helping respond to stress

The nervous system is a complex system that enables control and coordination in the body.

The brain is the control center of the body, responsible for processing and integrating information.
The spinal cord extends from the base of the brain down to the lower back, transmitting messages between the brain and the rest of the body.

Sensory nerves transmit information from sensory receptors to the CNS.
Motor nerves transmit signals from the CNS to muscles and glands.
The autonomic nervous system (ANS) controls involuntary actions, such as heart rate, digestion, and breathing.

The nervous system regulates body functions, such as movement, sensation, and emotion.
It integrates information from different parts of the body to produce a response.
It interprets and processes information from sensory receptors.
It maintains homeostasis, or a stable internal environment.

The synaptic cleft is the small gap between the terminal end of one neuron and the dendrite of another.
Neurotransmitters are chemical messengers released from the terminal end of a neuron, binding to receptors on adjacent neurons.
Synaptic transmission is the process of transmitting information from one neuron to another across the synapse.