Anatomy and Physiology 11/18/2013

Time Line 11/4 Introductions/Rules/Integumentary pre-test 11/11 Integumentary System (pg14-31) 11/18 Integumentary System(pg14-31) 12/2 Nervous System (1-13) 12/9 Nervous System (1-13) 12/16 Immune System (32-45) 1/6 Immune System(32-45) 1/14 Wright State Invitational

The Nervous System Two main divisions Central Nervous System (CNS) Brain Spinal cord Peripheral Nervous System (PNS) Somatic Nervous System Voluntary Info relayed to and from skin and muscle Autonomic Nervous System Involuntary Information relayed to internal organs

Autonomic Nervous System Has to main divisions Sympathetic Nervous System Controls organs during times of stress Fight of Flight Parasympathetic Nervous System Controls organs during times or rest Normal every day conditions

Autonomic Nervous System

The Neuron Composed of… Cell Body Dendrites Axon Myelin Sheath Contains nucleus and most of cytoplasm Dendrites Receives stimulus sends it towards cell body Axon Carries impulses away from cell body Myelin Sheath Lipid layer that insulates axon Schwan Cells Produce the myelin sheath Nodes of Ranvier Gaps in myelin sheath

The Neuron Three kinds Sensory Neuron Motor Neuron Interneuron Bring messages to CNS Motor Neuron Carry messages to CNS Interneuron Between sensory and motor neurons in CNS

Impulse This is how messages are propagated along a neuron. Caused by a stimulus in the environment All or nothing Impulses are of equal strength and self propagating Movement of ions across the cell membrane of a neuron Excitability: Ability of a neuron to react to a stimulus to convert it to an impulse

Synapse Small gap between axon of one neuron and the dendrites of another Chemicals (neurotransmitters) are released into the synapse to start the impulse of the next neuron or an effector (muscle or gland) The small junction insures one way transmission of impulse http://www.youtube.com/watch?v=dSkxlpNs3tU

Reflex arc Receptor reacts to stimulus Impulse conducted to CNS Internuron Impulse conducted from CNS to effector Effector response Reflex arc Afferent Pathway Efferent Pathway Spinal Reflex (does not involve higher brain centers)

Peripheral Nervous System Concists of … 12 pair of Cranial nerves Attach at under surface of the brain 31 pair of Spinal nerves Attach at spinal cord

Central Nervous System Brain Brain stem Medulla Midbrain Pons Diencephalon Thalamus Hypothalamus Cerebellum Cerebrum Spinal Cord

Meninges Three layers that surround brain and spinal cord that cushion and provide nutrition Dura Matter Outer most Very tough Arachnoid Matter Middle layer Connects to inner layers through web-like attachments Pia Matter Inner layer Thin, transparent, and tough Cerebrospinal fluid Buffers, nourishes, and detoxifies brain Flows through sub-arachnoid space between the arachnoid and pia matter

Regions of the Brain Cerebellum Cerebrum Thalamus Medulla Brain Stem Coordination of movement Involved with motor learning(muscle memory) Cerebrum Conscious activity such as emotion, thought, perception, and planning Thalamus Switch board of the brain Medulla Vital reflexes Heart beat Respiration Brain Stem Involuntary responses Relays info from spine to upper brain Hypothalamus Regulates activities of internal organs Monitors info from Autonomic nervous system Controls pituitary gland and its hormones Regulates sleep and appetite Make sure you study the Cerebellum and Cerebrum from your packet, we will have a quiz next time.