Your Nervous System Peripheral Nervous System

Explain which consists of is divided into that make up which is divided into Section 35-3 The Nervous System Sensory nerves Motor nerves Autonomic nervous system Somatic nervous system Central nervous system Peripheral nervous system Sympathetic nervous system Parasympathetic nervous system

PNS NERVES that connect the central nervous system to the rest of the body NERVES that connect the central nervous system to the rest of the body 1. Motor Division – impulses from CNS to muscles or glands Two Parts: Two Parts: Somatic Nervous System Somatic Nervous System Autonomic Nervous System Autonomic Nervous System 2. Sensory Division – transmits impulses from sense organs to CNS

Motor Division PNS

Somatic Nervous System Controls voluntary movement of the skeletal muscles Controls voluntary movement of the skeletal muscles

Autonomic Nervous System Controls involuntary actions Controls involuntary actions Subdivided into two system that have opposite effects on the same organs: Subdivided into two system that have opposite effects on the same organs: 1. Parasympathetic – decreases heart rate Controls internal organs during normal activity Controls internal organs during normal activity 2. Sympathetic – increases heart rate Controls internal organs during high stress activity Controls internal organs during high stress activity

Sensory Division PNS

1. Pain Receptors Throughout body; except brain Throughout body; except brain Respond to chemical released by damaged cells Respond to chemical released by damaged cells Important to recognize Important to recognize Danger Danger Injury Injury Disease Disease

2. Thermoreceptors In skin, body core, hypothalamus In skin, body core, hypothalamus Detect variations in body temperature Detect variations in body temperature

3. Mechanoreceptors Skin, skeletal muscle, and inner ears Skin, skeletal muscle, and inner ears Sensitive to Sensitive to Touch Touch Pressure Pressure Stretching of muscles Stretching of muscles Sound Sound motion motion

4. Chemoreceptors Nose and Tongue Nose and Tongue Chemical in external environment Chemical in external environment

Choroid Retina Blood vessels Optic nerve Fovea Vitreous humor Sclera Ligaments Iris Pupil Cornea Aqueous humor Lens Muscle Section 35-4 Figure The Eye

5. Photoreceptors Eyes Eyes Sensitive to Light Sensitive to Light DO NOT WRITE NEXT INFO – IT IS ON YOUR SHEET DO NOT WRITE NEXT INFO – IT IS ON YOUR SHEET

Vision Cornea Cornea Helps focus light Helps focus light Filled with aqueous humor Filled with aqueous humor Iris Iris Back of cornea Back of cornea Colored part of eye Colored part of eye Pupil Pupil Tiny muscles regulate the size Tiny muscles regulate the size Regulates amount of light Regulates amount of light Lens Lens Small muscles change its shape to focus on object near and far away Small muscles change its shape to focus on object near and far away Behind lens eye filled with vitreous humor Behind lens eye filled with vitreous humor Retina Retina Has photoreceptors Has photoreceptors No photoreceptors where optic nerve passes through the back of the eye; blind spot No photoreceptors where optic nerve passes through the back of the eye; blind spot Two types Two types 1. Rods – black and white 2. Cones – color

Pathway for Vision Reception Light  Light  cornea  cornea  iris and pupil  iris and pupil  lens  lens  Retina to photoreceptors  Retina to photoreceptors  Rods Rods Cones – Fovea Cones – Fovea Optic Nerve  Optic Nerve  Brain Brain

Auditory canal Tympanum Round windowEustachian tube Bone Cochlea Cochlear nerve Semicircular canals Oval window Stirrup Anvil Hammer Section 35-4 Figure The Ear

Hearing and Balance Ear Ear Two Functions Two Functions Hearing Hearing Detecting Positional change to movement Detecting Positional change to movement

Hearing Sound – air vibrations Sound – air vibrations Auditory canal – funnels air to tympanum (ear drum) Auditory canal – funnels air to tympanum (ear drum) Tymapnum – vibrates Tymapnum – vibrates Hammer, Anvil, Stirrup- vibrate and transmit vibrations to oval window Hammer, Anvil, Stirrup- vibrate and transmit vibrations to oval window Cochlea – filled with fluid and vibrations create pressure waves in the inner ear Cochlea – filled with fluid and vibrations create pressure waves in the inner ear Tiny hairs respond to waves and send messages to brain via the cochlear nerve Tiny hairs respond to waves and send messages to brain via the cochlear nerve

Balance Semicircular Canals Semicircular Canals 3 canals that form half circles 3 canals that form half circles Filled with fluid and hairs that detect motion of head in relation to gravity Filled with fluid and hairs that detect motion of head in relation to gravity

Auditory canal Tympanum Round windowEustachian tube Bone Cochlea Cochlear nerve Semicircular canals Oval window Stirrup Anvil Hammer Section 35-4 Figure The Ear

Smell and Taste Chemoreceptors pick up chemical reception in nose and mouth Chemoreceptors pick up chemical reception in nose and mouth Smell – olfactory bulb Smell – olfactory bulb Taste – taste buds Taste – taste buds Salty Salty Bitter Bitter Sour Sour Sweet Sweet

Cerebral cortex Nasal cavity Taste bud Smell sensory area Taste sensory area Thalamus Olfactory (smell) bulb Olfactory nerve Smell receptor Taste pore Taste receptor Sensory nerve fibers Section 35-4 The Senses of Smell and Taste

Touch and Related Senses Largest sense organ? Largest sense organ? SKIN SKIN Sensory Receptors Sensory Receptors Temperature Temperature Touch Touch Pain Pain Greatest density of touch receptors Greatest density of touch receptors Fingers Fingers Toes Toes Face Face

Concept Map which consists of is divided into that make up which is divided into Section 35-3 The Nervous System Sensory nerves Motor nerves Autonomic nervous system Somatic nervous system Central nervous system Peripheral nervous system Sympathetic nervous system Parasympathetic nervous system