Jennie May & Yasmin Ali. Coordinates the activities between the various parts of the human body. The...
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Transcript of Jennie May & Yasmin Ali. Coordinates the activities between the various parts of the human body. The...
Jennie May & Yasmin Ali
Nerves Presentationpt. 2
Coordinates the activities between the various parts of the human body.
The central nervous system includes: Brain
Controls movement, sensation, thinking, memory, speech. (In depth detail of brain will be further on)
Spinal Cord Transmits messages back and forth between
the brain and peripheral nerves.
Central Nervous System
Transfers information to and from the CNS. It also regulates movement and internal environment.
The cells that carry to the CNS are called sensory nervous cells, and those carrying from are called motor nervous cells. And these cells send information due to internal organs or external stimuli.
Peripheral Nervous System
“Left–Right pairs of cranial and spinal nerves with their associated ganglia”
Cranial NervesEmerges from or enters the BrainSensory, motor or mixed nerves. Humans have
12 pairs. Spinal Nerves
Originate in spinal cord and extend below the head.
Consists of all mixed nerves. Humans have 31 pairs.
PNS Structure
Motor Neuron Cells carry the information from the CNS to organs, muscles, and glands.
Motor Neuron cells are divided into two subcategories which are Somatic Nervous System and Automatic Nervous System.
Motor Neuron
It controls :the skeletal muscles and carries to and from
the skeletal muscle due to external stimuli. sensory organs such as the skin.
The Somatic Nervous system is voluntary with exception to reflex reactions.
Somatic Nervous System
Regulates internally through the smooth and cardiac muscles as well as organs of the digestive ,cardiovascular, etc.
This is an involuntary control unlike Somatic. This also carries some exceptions such as the
diaphragm (breathing), bladder muscles, and heart rate, which can all be controlled.
It is further divided into three subsections: Sympathetic DivisionParasympathetic DivisionEnteric Division
Autonomic Nervous System
Sympathetic DivisionControls activities for increased energy generation. Ex:
Flight or Fight. These nerves increase heart rate, dilate pupils, and relax the bladder.
Parasympathetic DivisionServes as the opposite and decreases heart rate,
constricting pupils, and contracting the bladder. These nerves are more for activities that control energy expenditures.
Enteric Division Networks of Neurons in digestive tract, pancreas, and
gallbladder. These nerves can be controlled independently, but are usually regulated by the Parasympathetic and Sympathetic Division.
Autonomic Nervous System Divisions
http://www.youtube.com/watch?v=dOYOdJG0E0s
They are used to respond to stimuli. They help process information from the environment.
Focused more on where the action potentials go rather than what triggers them.
Sensory Reception is the detecting of a stimulus by cells which are called sensory receptors.
Receptors
• Classification–Exteroreceptors•Outside the body–Heat, light, pressure
– Interoreceptors• Inside the body–Blood pressure, body position
Sensory Receptors
MechanoreceptorsTouch, pressure, gravity, stretch, movement
Chemoreceptors Taste and smell
PhotoreceptorsAbsorb light
ThermoreceptorsTemperature changes
ElectroreceptorsElectric stimuli
Sensory Reception
Sensory Transduction Stimulus energy converted into change in
membrane potential.Receptor Potential: The change in membrane
potential Graded potentials via the magnitude and strength
of the stimulus. Results from the opening and closing of ion
channels in the plasma membrane
Amplification Increasing the stimulus energy in sensory
pathways
Function of Sensory Receptors
Transmission Identical action potentials (the magnitude
affects the frequency)Integration
Processing of the sensory information Adaptation: decrease in responsiveness to
repetitive stimuli Pain and touch receptors
Function continued…