The Muscular System
• Muscles contribute to the outward appearance of animals and are essential for movement, posture, breathing, circulation, digestion, and many other functions
Muscular System
• Types of muscle fibers• Smooth• Cardiac• Skeletal
Types of Muscle
The Muscular System
• Muscles are classified as being voluntary or involuntary– Voluntary muscles are
those that can be contracted or relaxed at will
– Involuntary muscles are regulated by the nervous and endocrine systems
Functional Unit of the Muscle
• Sarcomere– fundamental functional
unit of striated muscle (skeletal and cardiac)
– http://highered.mheducation.com/sites/0072495855/student_view0/chapter10/animation__sarcomere_contraction.html
The Nervous System
• The nervous system is a complex network that regulates most activities of the body, coordinates movements, and relays sensations
The Nervous System
• Two major divisions– central nervous
system • Brain and spinal cord
– peripheral nervous system• Nerves throughout body
for sensory and motor control
The Nervous System
• Nerve cells are called neurons – Dendrite– Axon– Synapse
The Nervous System
• The brain controls most activities of the body, both voluntary and involuntary– Major divisions• Cerebrum• Cerebellum• Diencephalon• Brain stem
Major Divisions of the Nervous System
• Cerebrum– Divided into the L and R
hemispheres– Connected by corpus
callosum– Functions in: determining
intelligence and personality; thinking; perceiving; language; motor function; planning and organizing; touch sensation
Major Divisions of the Nervous System
• Cerebellum– Back of brain– Functions in:
maintenance of balance and posture; coordination of voluntary movements; motor learning; cognitive functions (language)
Major Divisions of the Nervous System
• Diencephalon– Include: hypothalmus,
thalmus, and epi- and subthalmus
– Functions to: direct sense impulses throughout body; autonomic (involuntary/PNS), motor, and endocrine control; homeostasis; and touch sensation
Major Divisions of the Nervous System
• Brain stem – Stem-like part of the base
of the brain connected to spinal cord
– Consists of: midbrain, pons, and medulla oblongata
– Functions to: control the flow of messages between the brain and body; control breathing, swallowing, heart rate, blood pressure, consciousness; and identify if one is awake/alert or tired/sleepy
The Nervous System
• Composition– Gray matter is
formed by the aggregation of the cell bodies of neurons
–White matter is composed of myelinated nerve cell processes
The Nervous System
• Function– Gray Matter: muscle control;
sensory perceptions, such as seeing and hearing; memory; emotions; and speech
– White Matter: relays sensory information from the rest of the body to the cerebral cortex; regulates autonomic functions (body temperature, heart rate and blood pressure); expression of emotions; and regulation of food and water intake