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