Unit 3 - The Nervous System Flashcards
Describe six functions of the nervous system.
Coordinates movement. It plans, initiates, and asserts ongoing control over every move you make.
** Processes sensory input.** This amazingly diverse category includes smell, vision, taste, hearing, and somatosensory information (pain, warmth, an itch you need to scratch…) These functions allow you to receive and interpret information from your joints, ligaments, muscles, and skin.
**Initiates and maintains life-sustaining functions. **These include your innate need to find water, food, and a mate.
Learns and forms memories: Learning and memory are the primary elements of cognition.
Experiences emotions: These include feelings of fear, pleasure, attachment, and drive.
Controls arousal: Consciousness and sleep regulation are parts of this function.
Describe six functions of the nervous system.
Coordinates movement: It plans, initiates, and asserts ongoing control over every move you make.
** Processes sensory input**: This amazingly diverse category includes smell, vision, taste, hearing, and somatosensory information (pain, warmth, an itch you need to scratch…) These functions allow you to receive and interpret information from your joints, ligaments, muscles, and skin.
**Initiates and maintains life-sustaining functions. **These include your innate need to find water, food, and a mate.
Learns and forms memories: Learning and memory are the primary elements of cognition.
Experiences emotions: These include feelings of fear, pleasure, attachment, and drive.
Controls arousal: Consciousness and sleep regulation are parts of this function.
The nervous system are divided into these two systems?
The central nervous system (CNS) and peripheral nervous system
Define:
Central nervous system (CNS)
The nervous system cells that make up the brain and spinal cord.
Define:
Peripheral nervous system (PNS)
The nervous system cells that provide information to the brain and spinal cord.
The nervous system consists mainly of which two cells? In avergare how many are there of each?
Neurons: 86 billions
Glia: 1 trillion
Define:
Neuron
The nervous system cell that produces action potentials to communicate with other neurons, muscles, or glands.
Define:
Glia
The nervous system cell that protects and supports neurons but does not produce action potentials.
Define:
Action potential
The electrical signal produced by a neuron or muscle spindle.
Which kind of neuron are there in the human nervous system?
Motor neurons
Sensory neurons
Interneurons
Define:
Motor neurons
A nervous system cell that transmits information away from the spinal cord to muscles or glands.
Define:
Sensory neurons
A nervous system cell that transmits information regarding movement, sight, touch, sound, and smell to the brain and spinal cord.
Define:
Interneurons
A nervous system cell that creates circuits between motor or sensory neurons, and within the brain and spinal cord.
Define:
Dendrites
The portion of a neuron that receives information from other neurons.
In the context of neurons, define cell body
The cell body, or soma, is the bulbous end of a neuron that contains the nucleus (DNA). This part of the neuron integrates information and determines whether there’s enough to create an action potential.
Define:
Axon
The axon is the transmitter portion, relaying signals to other neurons, muscles, or organs. The axons that travel from the spinal cord to the feet can be up to a meter long but just 100 microns (a tenth of a millimeter) wide.
Define:
Muscle spindle
A muscle spindle is a sensory receptor within muscle that detects changes in length and helps regulate contraction. It sends information to the sensory cell body. The information then travels through the axon to the spinal cord, where it communicates with motor neurons or interneurons.
Define:
Synapse
An area between neurons, or between a neuron and muscles or glands, where electrical or chemical signals are transmitted.
Define:
Acetylcholine
The chemical (a neurotransmitter) a motor neuron releases to cause muscle contractions.
Define:
Neuromuscular junction
The area between a motor neuron and muscle fiber where acetylcholine is released.
Define:
Myelin
A fatty sheath around the axon of a nerve that provides electrical insulation, protection, nourishment, and faster signal transmission.
How fast can signals travel through a nerve?
Up to 90 m/s
The Peripheral Nervous system (PNS) can be divided into which systems?
The PNS can be further subdivided into the somatic nervous system and autonomic nervous system.
Define:
Somatic nervous system
The division of the peripheral nervous system that controls voluntary movement.
Define:
Autonomic nervous system
The division of the peripheral nervous system that controls subconscious actions such as breathing, heart rate, and digestive processes.
The Automatic Nervous System can be divided into which subsystems?
It’s further divided into the sympathetic and parasympathetic nervous systems.
Define:
Sympathetic nervous system
The division of the autonomic nervous system that generates the “fight or flight” response.
Define:
Parasympathetic nervous system
The division of the autonomic nervous system that generates the “rest or digest” response.
Define:
Norepinephrine
The hormone/neurotransmitter released by the CNS and sympathetic nervous system that triggers the “fight or flight” response.
Describe:
The forebrain
The forebrain includes the cerebrum, which helps learn and control movement, and the diencephalon, which relays and integrates information from different parts of the brain and spinal cord. The cerebrum is further divided into right and left cerebral hemispheres, which are connected by the corpus callosum.
Describe:
The brainstem
The brainstem consists of the midbrain, pons, and medulla. It mediates sensory and motor control of the head, neck, and face along with balance. The brainstem also contains the sensory and motor pathways that travel to other parts of the CNS..