Nervous System Modified by K.Riggins Hewitt-Trussville High School Anatomy and Physiology 2016 Directions: Students should read each slide carefully. There are 3 assignments embedded into the presentation. All should be completed by your next class period. February 2, 2016

Three Basic Functions 1. Sensory Function – gathers info about changes occurring within and around the body - Sensory receptors, at ends of peripheral nerves send signals (nerve impulses) to the CNS. Sensory Neuron 2. Integrative Function – information is “brought together,” interpreted, to create sensations, create thoughts, add to memory, make decisions, etc. Association neuron or interneuron 3. Motor Function – responses to signals (impulses). Signals sent from the CNS to effectors (muscles or glands). The goal is usually to maintain stable conditions (especially internal) – Homeostasis. Motor neurons.

The nervous system controls Feeling Thinking Remembering Being aware of the world Homeostasis Enable the body to respond to changing conditions Allows information to stimulate muscles and glands

Know some vocabulary Neurons- nerve cells that make up nervous tissue; react to physical and chemical changes Neurons transmit information, nerve impulse to other neurons or to cells Cell body- the round part of a neuron –Dendrites- receive messages; numerous –Axons- send messages; single

The organs of the nervous system are in 2 major groups: Central Nervous System (CNS)- Brain and Spinal chord Peripheral Nervous System (PNS)- the nerve cells that connect the CNS to other body parts

Sensory Receptors The sensory function is controlled by sensory receptors at the ends of peripheral neurons. Gather information by detecting changes –Light, sound, temperature, O 2 level

Effectors- muscles or glands that act when stimulated by nerve impulse –Somatic nervous system- voluntary; skeletal muscular system –Autonomic nervous system- involuntary; heart and glands

more vocabulary…. Neurofibrils- thread like structures that extend into the axons; carry impulse Chromatophilic substance- make proteins; ribosomes attached Nodes of Raniver- narrow gaps between Schwann cells

The brain has: White matter- has myelin (myelinated), made of neurofibrils Gray matter- no myelin (unmyelinated), made of cell bodies

Neuroglial cells Provide support and nutrients for neurons Produce myelin (a fatty lipoprotein) 1.Microglial cells- in the CNS phagocytocize bacterial cells 2.Oligodendrocytes- provide insulation, myelin sheath, around axons 3.Astrocytes- provide support between bloodvessels and neurons, form scar tissue in the CNS 4.Ependymal cells- covers specialized brain cells

Classification of Neurons Structural Difference- –Multipolar Neurons- most in the CNS; one axon and many dendrites –Bipolar neurons- eyes, nose, and ears; one dendrite and one axon –Unipolar neurons- most in the PNS; one branch the separates into a dendrite and an axon

Functional difference- –Sensory neurons- skin or sensory organs; receptor ends at the end of the dendrite carry impulses from peripheral body parts to the CNS –Interneurons- send messages from the CNS to other parts of the CNS –Motor Neurons- carry impulses out of the CNS to effectors (send message to muscle that contract)

Synapse The junction between any two communicating neurons. An impulse must jump a synaptic cleft before transmitting the impulse using acetylcholine Nerve pathway- impulse travels along What does it mean when someone is epileptic?

Note Quiz Record in your science composition book. Question in blue or black ink. Answers in pencil. 1.What are the three basic functions of the nervous system? 2._________receive messages; numerous 3._________ send messages single 4.__________-the nerve cells that connect the CNS to other body parts 5._____ nervous system-involuntary; heart and glands 6._______-narrow gaps between Schwann cells 7-9.What are the three classifications of neurons 10. _____send messages from the CNS to other parts of the CNS

Homework Quiz Use a pencil to print the answers only in your composition book. 1.Feeling, thinking, remembering, moving, and being aware of the world require____________ 2.Axon – 3.As a result of integrative function we make decisions and use ___________ ___________ to act on them. 4.Nerve impulse travel along the________ 5.The synapse is ___________. 6.The gap that a nerve impulse must cross is a ________ 7.Astrocytes 8.Schwann cells 9-10.The nerve sender is the ________________, and the nerve receiver is the _____________.

If you think of the brain as a central computer that controls all bodily functions, then the nervous system is like a network that relays messages back and forth from the brain to different parts of the body. It does this via the spinal cord, which runs from the brain down through the back and contains threadlike nerves that branch out to every organ and body part.

Brain 1.Cerebrum- largest part, controls thinking, moving, and sensory function (lobes) 2.Diencephalon- processes sensory information (center) 3.Brain stem- connects brain to spinal chord (bottom) 4.Cerebellum- coordination (on back)

Frontal lobe parietal lobe Occipital lobe temporal lobe

1.Cerebellum - the part of the brain below the back of the cerebrum. It regulates balance, posture, movement, and muscle coordination. 2.Corpus Callosum - a large bundle of nerve fibers that connect the left and right cerebral hemispheres. In the lateral section, it looks a bit like a "C" on its side. 3.Frontal Lobe of the Cerebrum - the top, front regions of each of the cerebral hemispheres. They are used for reasoning, emotions, judgment, and voluntary movement. 4.Medulla Oblongata - the lowest section of the brainstem (at the top end of the spinal cord); it controls automatic functions including heartbeat, breathing, etc. 5.Occipital Lobe of the Cerebrum - the region at the back of each cerebral hemisphere that contains the centers of vision and reading ability (located at the back of the head).

6.Parietal Lobe of the Cerebrum - the middle lobe of each cerebral hemisphere between the frontal and occipital lobes; it controls visual memory and auditory patterns 7.Pituitary Gland - a gland attached to the base of the brain (located between the Pons and the Corpus Callosum) that secretes hormones. 8.Pons - the part of the brainstem that joins the hemispheres of the cerebellum and connects the cerebrum with the cerebellum. It is located just above the Medulla Oblongata and regulates is 9.Spinal Cord - a thick bundle of nerve fibers that runs from the base of the brain to the hip area, running through the spine (vertebrae). 10.Temporal Lobe of the Cerebrum - the region at the lower side of each cerebral hemisphere; contains centers of hearing and memory (located at the sides of the head). Assignment: Use black ink to print the name only of all the parts of the brain in your composition books.

Reflex behavior Reflexes are automatic subconscious responses to changes A Doctor may check your knee-jerk reflex to make sure your reflexes such as homeostasis, heart rate, breathing rate, blood pressure, and digestion are working correctly.

Meninges Membrane that encloses and protects the CNS Has 3 layers –Dura mater-outermost layer, blood vessels, nerves –Arachnoids mater- middle layer no blood vessels Subacracnoid layer- contains cerebrospinal fluid –Pia mater- hugs the brain, many blood vessels to nourish

Cerebrospinal Fluid collection

Spinal Cord Thirty-one pairs of spinal nerves that branch to different body parts –Cervical enlargement- supplies nerves to upper limbs –Lumbar enlargement- supplies nerves to lower limbs Conduct nerve impulses, serve as a central for spinal reflexes –Ascending and descending