Flashcards in Lecture Quiz #3 Deck (52)
How do neurons communicate?
By electrical and chemical signals which are rapid and specific, and cause immediate responses
What are the 3 overlapping functions of the nervous system?
1. Sensory input
2.integration and motor output
3. Motor output
Nervous system has millions of sensory receptors that monitor change inside and outside the body. The information gathered is called sensory input
Sensory input is processed and interpreted. The info is used to make judgements and sends out orders
The nervous system activates effector organs such as muscles and glands to cause a response calls motor output
Two parts of the nervous system
Central nervous System (CNS)
Peripheral nervous System (PNS)
Found in dorsal body cavity, consists of brain and spinal chord. CNS integrates info and is control center
Consists of nerves that exted from brain and spinal chord. Spinal nerves carry impulses to and from spinal chord.cranial nerves carry impulses to and from the brain. Links all pearls of body to CNS
What is a nerve?
A bundle of axons
2 functional subdivisions of PNS
Sensory/ afferent division (carrying toward)
Motor or efferent division (carrying away)
Sensory/Afferent division of PNS
Somatic sensory: fibers gather Info from from skin, skeletal muscles and joints
Visceral sensory: gathers info from visceral organs
Sensory division keeps CNS informed of what is going on in side and out side of the body.
The 2 main parts of the motor division
1. Somatic nervous system: sends impulses to CNS to skeletal muscles also called voluntary nervous system
2. Autonomic nervous system: made up of visceral motor fibers that regulate smooth muscle tissue, cardiac a muscle and glands with out thinking about it; also called the involuntary nervous system
The autonomic nervous system is further made up of 3 sub divisions ____________.
1. Sympathetic division
2. Parasympathetic division
Cellularity of nervous tissue
Nervous tissue is made up of 2 kinds of cells
Neuroglia- supper cells
Neurons- excitable nerve cells
What is the master controlling system of the body?
The nervous system
Also called neurolemmocytes, surround all nerve fibers in PNS and form myelin sheaths around thicker nerve fibers. Schwann cells a are vital to the repair of damaged peripheral nerve fibers
Special characteristics of neurons
1. Extreme longevity- lasts a life time
2. Amitotic- do not replicate themselves
3. High metabolic rate- needs a lot of O2 and glucose
Neuron cell body
Perikaryon or soma
Along with microtubules maintains cell's shape. They are intermediate filaments
Where are most neuron cell bodies located?
In the CNS, they are protected by the bones of the skull and vertebral column
Clusters of cell bodies in CNS
Clusters of cell bodies that lie along the nerves of the PNS
The brain and spinal chord contain both ________.
Neuron cell bodies and their processes
The PNS consists chiefly of________.
Bundles of neuron processes in CNS
Bundles of neuron processes in PNS
Are the main receptive or input regions of the neuron. The usually receive incomming messages towards the cell body. These electrical signals are not action potentials but short distance graded potentials
Any long axon