Module BL1004: Animal Physiology Overview

The network of nerve cells that controls and coordinates all bodily functions.

The part of the nervous system that processes information and generates responses. It includes the brain and spinal cord.

The part of the nervous system that connects the CNS to the rest of the body. It carries sensory information to the CNS and motor commands from the CNS to muscles and glands.

Specialized cells that transmit signals within the body.

Highly branched extensions of a neuron that receive signals from other neurons.

A long extension of a neuron that transmits signals from its terminal branches to other cells at synapses.

The difference in electrical charge across the plasma membrane of a neuron.

The membrane potential of a neuron not sending signals.

A junction between two neurons where communication occurs.

The process by which action potentials jump between the nodes of Ranvier in myelinated axons.

A type of synapse where electrical current flows directly from one neuron to another.

A type of synapse where a chemical neurotransmitter carries information across the synaptic cleft.

The neuron that releases the neurotransmitter at a synapse.

The neuron that receives the neurotransmitter at a synapse.

A chemical messenger that transmits information across the synapse.

The clustering of sensory organs at the front end of the body in bilaterally symmetrical animals.

The sodium-potassium pump actively moves sodium ions (Na+) out of the neuron and potassium ions (K+) into the neuron, maintaining the concentration gradients.

When ion channels open, the concentration gradients created by the sodium-potassium pump drive the movement of ions, generating an electrical potential across the membrane.

A period after an action potential where a neuron cannot be stimulated to fire another action potential, ensuring that the impulse travels in one direction only.

The process by which an action potential travels along the axon, regenerating itself at each point.

The speed of an action potential is directly proportional to the diameter of the axon.

A fatty sheath that surrounds the axon of some neurons, increasing the speed of action potential conduction.

Glia are supporting cells in the nervous system, and they play a role in forming the myelin sheath: Oligodendrocytes in the CNS and Schwann cells in the PNS.

Found in simpler cephalized animals like flatworms, it's a brain and nerve cords, forming a network for information flow.

Part of the CNS, responsible for processing information and generating responses.

Part of the CNS, extending along the body, carrying signals to and from the brain.

Part of the CNS in vertebrates, including brain and spinal cord, processing information and generating responses.

Part of the CNS, containing neuron cell bodies, dendrites, and unmyelinated axons, responsible for processing information.

Part of the CNS, containing bundles of myelinated axons, responsible for faster signal transmission.

The body's automatic response to a stimulus. For example, a knee-jerk reflex triggered by a doctor's mallet.

The midbrain is involved in processing sensory information, the pons regulates breathing, and the medulla oblongata controls essential functions like breathing, heart rate, and digestion.

The cerebellum is crucial for coordination and accuracy during movement, perception, and thinking. It also helps with learning and remembering motor skills like hand-eye coordination.

The epithalamus generates cerebrospinal fluid and includes the pineal gland, while the thalamus acts as a sensory input hub to the cerebrum and a motor output hub. The hypothalamus regulates essential bodily processes like hunger, thirst, and temperature.

The cerebrum consists of two hemispheres, each having a cerebral cortex (gray matter) and white matter with basal nuclei. In humans, the cerebral cortex is the largest and most complex part of the brain.

The corpus callosum is a thick band of axons that connects the two hemispheres of the cerebrum, enabling communication between them. The right hemisphere controls the left side of the body, and vice versa.

The cerebral cortex is responsible for controlling voluntary movement and cognitive functions. Each hemisphere has four lobes: frontal, temporal, occipital, and parietal. Each lobe contains sensory areas and association areas where information is integrated.

The limbic system is involved in generating and experiencing emotions. It's a ring of structures surrounding the brainstem, including the amygdala, hippocampus, and parts of the thalamus.

The part of the peripheral nervous system that controls involuntary bodily functions such as heart rate, digestion, and breathing.

The division of the autonomic nervous system that generally prepares the body for 'fight or flight' responses. It increases heart rate, dilates pupils, and redirects blood flow to muscles.

The division of the autonomic nervous system that generally promotes 'rest and digest' activities. It slows heart rate, constricts pupils, and stimulates digestion.

The part of the autonomic nervous system that controls the digestive system. It is a network of neurons within the walls of the digestive tract.

The ability of the sympathetic and parasympathetic divisions to have opposite effects on target organs, ensuring a balanced and controlled internal environment.

The part of the brain that connects the cerebrum and cerebellum to the spinal cord. It controls vital functions like breathing, heart rate, and blood pressure.

The specialized areas of the brain responsible for different functions, such as sensory processing, motor control, and emotions.

The process of conducting information from the brain to the body, for example, carrying motor commands to muscles.

The process of transmitting information from the body to the brain, for example, carrying sensory information from the senses to the brain.

The process of moving the body, which is controlled by the motor system of the peripheral nervous system.

A series of interconnected nerve cells that forms a network for communication in simpler animals.

The difference in electrical charge across a neuron's membrane when it's not transmitting signals. It's like a battery, with one side being slightly more negative than the other.

Sodium-potassium pumps embedded in the neuron's membrane actively move sodium ions out and potassium ions in, creating concentration gradients. It's like a bouncer letting more potassium in and more sodium out.

When ion channels open, the concentration gradients drive the movement of ions, generating an electrical potential difference. It's like opening a gate and letting the stored energy flow out.

After an action potential, the neuron cannot be stimulated again for a brief period. This ensures the signal travels in one direction only and prevents backward propagation. It's like a one-way street for signals.

An action potential travels down the axon by regenerating itself along the way, but it's prevented from traveling backward by the inactivated sodium channels. It's like a domino effect, but only going forward.

The speed of an action potential increases with the diameter of the axon because the signal has more space to travel. It's like a wider pipe for the signal to flow through.

Myelin sheaths, formed by glial cells, insulate the axon, allowing the signal to jump from one node to another, increasing the speed of transmission. It's like jumping over obstacles instead of hopping through them.

These are specialized cells - oligodendrocytes (CNS) and Schwann cells (PNS) - involved in the formation of myelin, an insulating layer around the axon. They're like helpers for the signal to travel faster.

The nervous system is the body's control center, responsible for receiving information from the environment, processing it, and coordinating responses.

The nervous system uses three key functions for communication: sensory input, integration, and motor output. Sensory neurons detect stimuli, interneurons in the CNS process information, and motor neurons trigger responses.

Neurons are specialized cells that transmit information through electrical signals. They have dendrites receiving signals, an axon transmitting signals, and a cell body containing its machinery.

The membrane potential is the difference in electrical charge across a neuron's membrane. This difference in charge is critical for transmitting messages.

A synapse is a junction between two neurons where communication occurs. Chemicals called neurotransmitters carry signals across the gap between neurons.

Cephalization is the evolutionary development of a head region with concentrated sensory organs. This allows animals to sense their environment more efficiently.

The sodium-potassium pump actively transports sodium ions out of the neuron and potassium ions into the neuron. This creates concentration gradients that are crucial for generating electrical signals.

A cluster of nerve cell bodies, found in the peripheral nervous system and also within the central nervous system, responsible for processing and relaying information.

The tissue in the CNS that consists of neuron cell bodies, dendrites, and unmyelinated axons. It is responsible for processing information and generating responses.

The tissue in the CNS that consists of bundles of myelinated axons. It is responsible for transmitting information quickly between different parts of the CNS.

The brainstem, located at the base of the brain, connects the cerebrum and cerebellum to the spinal cord. It controls essential functions like breathing, heart rate, and blood pressure.

The midbrain is involved in sensory information processing, the pons regulates breathing centers in the medulla, and the medulla oblongata controls vital functions like breathing, cardiovascular activity, digestion, and other essential processes.

The cerebellum is crucial for coordination and accuracy during movement, perception, and thinking. It also plays a role in learning and remembering motor skills, such as hand-eye coordination.

The diencephalon develops into three regions: the epithalamus, responsible for generating cerebrospinal fluid and containing the pineal gland; the thalamus, the main input center for sensory information to the cerebrum and the main output center for motor information leaving the cerebrum; and the hypothalamus, which regulates homeostasis and basic survival behaviors like feeding, fighting, fleeing, and reproduction.

The corpus callosum is a thick band of axons connecting the two hemispheres of the cerebrum, enabling communication between them. The right hemisphere controls the left side of the body, and vice versa.

The limbic system is responsible for generating and experiencing emotions. It's a ring of structures surrounding the brainstem, including the amygdala, hippocampus, and parts of the thalamus.