Nervous System Flashcards
The human
body is organized as follows:
Atoms > Cells > Tissues > Organs > Organ Systems > Organism
The body has 11 organ systems (a group of organs working together to perform biological functions), but the nervous,
muscular, and skeletal systems are the most prominent regarding human movement. Of those three systems, the nervous
system is the most important as it is the control center of the body.
A neuron or nerve cell:
the most fundamental component of the brain and nervous system
Cell body: the core and central structure of a neuron containing a nucleus and other specialized
organelles that aid in nervous system function
Axon: the thin tail like structure of a neuron that generates and conducts nerve impulses
Dendrites: rootlike structures branching out from the cell body that receive and process signals from
the axons of other neurons
Neurosecretory tissues:
translate neural signals into chemical stimuli. These tissues make neurohormones,
hormones produced and released by nerve cells that are released into the bloodstream.
Nervous tissue:
tissue found in the brain, spinal cord, and nerves that coordinates body activities
Neuroglia:
cells in the brain and spinal cord that form a supporting structure for the neurons and provide
them with insulation
Neurosecretory tissues:
neurons that translate neural signals into chemical stimuli
Decussation:
the point of crossover of the nervous system in vertebrates located between the medulla
oblongata and the spinal cord
Hypothalamus:
the region at the base of the brain responsible for maintaining homeostasis
Homeostasis:
a self-regulating process by which the body maintains the stability of its physiological processes
for the purpose of optimal function
Classications of neurons
►Sensory neurons: nerve cells involved in communicating tactile, auditory, or visual information
► Motor neurons: nerve cells that initiate muscle contraction or activate glands
► Interneurons: nerve cells that connect neurons to other neurons
Lobes of the brain
► Frontal lobe: the brain lobe involved in motor control, emotion, and language
► Motor cortex: the region of the frontal lobe that plans and coordinates movement
► Prefrontal cortex: the part of the frontal lobe responsible for high-level thinking and language
► Parietal lobe: the brain lobe involved in processing sensory information
Somatosensory cortex: the region of the parietal lobe responsible for processing sensations such as
pain, temperature, and touch
► Temporal lobe: the lateral lobe of the brain responsible for hearing, memory, and emotion
Auditory cortex: the region of the temporal lobe responsible for hearing
► Occipital lobe: the posterior lobe of the brain responsible for vision
Visual cortex: the specic region of the occipital lobe responsible for sight and visual perception
► Central nervous system (CNS):
the part of the nervous system consisting of the brain and spinal cord;
receives sensory input and organizes, analyzes, and processes neural information
Cerebrum: the uppermost and largest part of the brain consisting of a left and right hemisphere,
responsible for receiving and processing sensory information and controlling the body
Cerebellum: the region of the brain responsible for conscious motor coordination
Brain stem: the trunk of the brain, consisting of the medulla oblongata, pons, and midbrain that
continues downward to form the spinal cord
Cerebral cortex: the part of the brain where most neural integration occurs
Midbrain: the brain region responsible for motor movement and processing auditory and visual information
Pons: the brain region responsible for posture, facial movement, and sleep
Medulla oblongata: the base of the brain stem, responsible for involuntary functions such as swallowing,
sneezing, and heart function
Thalamus: the brain region responsible for relaying sensory and motor signals and regulating
consciousness
Spinal cord: the neural tissue extending from the medulla oblongata to the lumbar region (lower back)
of the vertebral column that connect the body and the brain
Peripheral nervous system (PNS):
the nerves and ganglia (relay areas for nerve signals) outside of the brain
and spinal cord
Reflexes are processed directly by the spinal cord (they do not travel to the brain).
The PNS consists of afferent and efferent neurons that are responsible for communication between
the body and the brain.
– Cranial nerves: the 12 sensory and motor nerves extending directly from the brain
– Spinal nerves: bundles of nerves connected to the spinal cord carrying information toward
the periphery
– Afferent neurons: send information from the body toward the CNS
– Efferent neurons (motor neurons): carry signals from the CNS to the muscles to generate movement
- Somatic nervous system: the part of the nervous system controlling voluntary movement
- Autonomic nervous system: the part of the nervous system responsible for involuntary
functions and movement
Sympathetic nervous system: the autonomic system responsible for “ght-or-ight”
Parasympathetic nervous system: the autonomic system responsible for “rest
and digest”
Functions of the nervous system///// - ► Sensory impulses
Internal stimuli: sensory input from within the body
External stimuli: sensory input from external sources
Mechanoreceptors: nervous system receptors responding to mechanical stimuli such as sound or touch
– Tactile receptors: collect and communicate sensations of touch
– Proprioceptors: communicate the position of the body and movement
– Baroreceptors: collect and communicate changes in blood pressure
Proprioception: perception or awareness of body movement or position in space
Myelin sheath: the insulation of neuron axons, made of proteins and fats, which propagates neural impulses
► Integration of sensory input
Nerve impulses: the electrical signals used for nerve communication
Sensory integration: the way the brain works to affect responses to neural input
