body systems review nervous system. complex and highly organized coordinates all of the many...
TRANSCRIPT
BODY SYSTEMS REVIEW
NERVOUS SYSTEM
NERVOUS SYSTEM
• Complex and highly organized• Coordinates all of
the many activities of the body• Allows the body to
respond and adapt to changes that occur both inside and outside the body
NEURON
• Neuron is also called a nerve cell• Basic structural unit of the nervous system• Parts of neuron• Cell body• Nucleus• Dendrites• Axon• Myelin sheath• Schwann’s cells• Node of Ranvier• Axon Terminals
NERVES
• Combination of nerve fibers• Located outside the brain and spinal cord• Afferent Nerves• Sensory nerves• Carry messages from all parts of the body to the brain
and spinal cord
• Efferent Nerves• Motor nerves• Carry messages from the brain and spinal cord to the
muscles and glands
• Associative- internuncial nerves• Carry both sensory and motor messages
THE NERVOUS SYSTEM
• Consists of two main divisions
• Central Nervous System • Consists of the brain and spinal
cord
• Peripheral Nervous System • Somatic nervous system• Autonomic nervous system
CENTRAL NERVOUS SYSTEMTHE BRAIN
• Cerebrum• Cerebellum• Diencephalon• Midbrain• Pons• Medulla oblongata
CENTRAL NERVOUS SYSTEM THE SPINAL CORD
• Continues down from medulla oblongata and ends at the 1st or 2nd lumbar vertebrae• Surrounded and protected by the
vertebrae• Responsible for many reflex actions• Carries sensory (afferent) messages
to the brain• Carries motor (efferent) message
from the brain
CENTRAL NERVOUS SYSTEM
Meninges - Three membranes that cover and protect the brain and spinal cord
1. Dura Mater– thick, tough outer layer2. Arachnoid Membrane– middle layer, delicate and web-
like3. Pia Mater– innermost layer, closely attached to the
brain and spinal cord, contains blood vessels that nourish the nerve tissue
CENTRAL NERVOUS SYSTEM
Ventricles – • Hollow spaces that connect with each other and with the
space under the arachnoid membrane (the brain has 4 ventricles)
• Filled with clear, colorless fluid called cerebrospinal fluid
Cerebrospinal Fluid• Serves as a shock absorber to protect the brain and
spinal cord• Carries nutrients to some parts of the brain and helps to
remove waste
PERIPHERAL NERVOUS SYSTEM
Consists of the somatic nervous system and the autonomic nervous system (ANS)
Somatic Nervous System• Contains 12 pairs of cranial nerves and their branches• Some are responsible for special senses, others receive general
sensations such as touch, pressure, pain, and temperature• Send out impulses for involuntary and voluntary muscle control
• Contains 31 pairs of spinal nerves and their branches• Carry messages to and from the spinal cord• 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal pairs
PERIPHERAL NERVOUS SYSTEM
Autonomic Nervous System-2 divisions of the ANS (sympathetic and parasympathetic)
1.Sympathetic Nervous System• Prepares the body to act (fight or flight)• Increases heart rate, respiration, and blood pressure• Decreases the activity in the digestive tract
2.Parasympathetic Nervous System• Counteracts the sympathetic nervous system• Returns the body to normal after the threat has passed
DISEASES AND ABNORMAL CONDITIONS
• Amyotrophic lateral sclerosis (ALS)• Carpal tunnel
syndrome • Cerebral palsy• Cerebrovascular
accident (CVA)• Encephalitis• Epilepsy or seizure
syndrome
• Hydrocephalus• Meningitis• Multiple sclerosis
(MS)• Neuralgia• Paralysis• Parkinson’s disease• Shingles or herpes
zoster