Control and Coordination LS Chapter 18LS Chapter 18

The Nervous System Group of organs that gathers, processes and responds to information gathered through the senses Group of organs that gathers, processes and responds to information gathered through the senses Acts very quickly Acts very quickly Can be less than 1 second between gathering and responding Can be less than 1 second between gathering and responding Touching something hot Touching something hot The information gathered is called a stimulus The information gathered is called a stimulus Can be a sight, sound, taste, smell or a feeling (touch) Can be a sight, sound, taste, smell or a feeling (touch) The reaction to the stimulus is called a response The reaction to the stimulus is called a response If the response is involuntary, it is a reflex If the response is involuntary, it is a reflex Vital in the maintenance of homeostasis Vital in the maintenance of homeostasis Keeps body’s internal conditions correct, no matter what is going on outside Keeps body’s internal conditions correct, no matter what is going on outside Split into 2 parts-The Central Nervous System (CNS) and the Peripheral Nervous System (PNS) Split into 2 parts-The Central Nervous System (CNS) and the Peripheral Nervous System (PNS)

Neurons Neurons are the functioning unit of the nervous system Neurons are the functioning unit of the nervous system Work to relay sensory information to and from the brain Work to relay sensory information to and from the brain 3 main parts of a neuron 3 main parts of a neuron Dendrite-Receives information Dendrite-Receives information Cell body-Processes information Cell body-Processes information Axon-Transmits information Axon-Transmits information 3 types of neuron 3 types of neuron Sensory-Send information from senses to the brain or spinal cord Sensory-Send information from senses to the brain or spinal cord Motor-Sends information from the brain and spinal cord to tissues and organs Motor-Sends information from the brain and spinal cord to tissues and organs Interneurons-Connect sensory and motor neurons Interneurons-Connect sensory and motor neurons

Information Transmission The area between neurons is called a synapse The area between neurons is called a synapse Neurons relay information by releasing chemicals called neurotransmitters Neurons relay information by releasing chemicals called neurotransmitters These neurotransmitters travel across the synapse from an axon of one neuron to a dendrite of another These neurotransmitters travel across the synapse from an axon of one neuron to a dendrite of another

The Central Nervous System The CNS includes the brain and spinal cord The CNS includes the brain and spinal cord Receives, processes, stores, and transfers information Receives, processes, stores, and transfers information

The Brain Control center of the body Control center of the body Receives and sends information. Also processes and stores information. Receives and sends information. Also processes and stores information. 3 main divisions: 3 main divisions: Cerebrum- Controls memory, language, and thought Cerebrum- Controls memory, language, and thought Broca’s Area-Language center of the brain Broca’s Area-Language center of the brain Cerebellum- Controls voluntary muscle movement and balance Cerebellum- Controls voluntary muscle movement and balance Muscle memory Muscle memory Brain Stem- Controls involuntary actions Brain Stem- Controls involuntary actions Heart, breathing, etc. Heart, breathing, etc. Connects brain to the spinal cord Connects brain to the spinal cord

Lobes of the Cerebrum 4 lobes that have different functions 4 lobes that have different functions Frontal Lobe Frontal Lobe Problem solving, emotion, reasoning, speaking, voluntary motor actions Problem solving, emotion, reasoning, speaking, voluntary motor actions Parietal Lobe Parietal Lobe Sensation, reading, body orientation Sensation, reading, body orientation Occipital Lobe Occipital Lobe Vision, color perception Vision, color perception Temporal Lobe Temporal Lobe Understanding language, behavior, memory, hearing Understanding language, behavior, memory, hearing

The Spinal Cord Tube-like structure of neurons that extends from the brain stem Tube-like structure of neurons that extends from the brain stem Transmits information to and from the brain Transmits information to and from the brain Protected by the vertebrae Protected by the vertebrae

The Peripheral Nervous System Connects the CNS to the rest of the body Connects the CNS to the rest of the body 2 parts 2 parts Somatic (SoNS)- Controls skeletal muscles and voluntary actions Somatic (SoNS)- Controls skeletal muscles and voluntary actions Autonomic (ANS)- Controls smooth and cardiac muscles (involuntary) Autonomic (ANS)- Controls smooth and cardiac muscles (involuntary) Think: Autonomic=Automatic Think: Autonomic=Automatic

Damage to the Nervous System Physical injuries Physical injuries Concussions- Traumatic injury to the brain Concussions- Traumatic injury to the brain Can impair ability to think, concentrate, or remember Can impair ability to think, concentrate, or remember Can cause headaches and blurry vision Can cause headaches and blurry vision Can, in rare cases, change personality, and increase anxiety, anger, or loss of interest in usual activities Can, in rare cases, change personality, and increase anxiety, anger, or loss of interest in usual activities Huge problem in sports Huge problem in sports Paralysis- inability to control parts of the body, or loss of sensation Paralysis- inability to control parts of the body, or loss of sensation Especially common in spinal cord injuries (broken neck/back) Especially common in spinal cord injuries (broken neck/back) Drugs kill neurons and impair abilities Drugs kill neurons and impair abilities Unlike most cells, neurons do not regrow or repair Unlike most cells, neurons do not regrow or repair

Sensory System Part of the Nervous System that detects or senses the environment Part of the Nervous System that detects or senses the environment Humans have 5 senses Humans have 5 senses Sight Sight Hearing Hearing Smell Smell Taste Taste Touch Touch The information is collected by specialized structures called receptors The information is collected by specialized structures called receptors Each sense uses different receptors Each sense uses different receptors

Vision Eye collects and transmits to the brain Eye collects and transmits to the brain Parts of the eye Parts of the eye Cornea-outer membrane. Collects light and directs it into the eye. Cornea-outer membrane. Collects light and directs it into the eye. Changes the direction to focus it Changes the direction to focus it Iris and Pupil- Iris is the colored portion of the eye. Pupil is the black circle. Iris and Pupil- Iris is the colored portion of the eye. Pupil is the black circle. The iris controls the size of the pupil to adjust the amount of light entering. The iris controls the size of the pupil to adjust the amount of light entering. Pupil decreases in size when bright, and dilates (increases in size) when dark to collect more light Pupil decreases in size when bright, and dilates (increases in size) when dark to collect more light Lens- Changes the direction of light again to focus it on the retina Lens- Changes the direction of light again to focus it on the retina Retina-area at the back of the eye that contains cells called photoreceptors Retina-area at the back of the eye that contains cells called photoreceptors Photoreceptors, called rods and cones, send the information as electrical signals through the optical nerve to the brain Photoreceptors, called rods and cones, send the information as electrical signals through the optical nerve to the brain

Vision Problems Nearsightedness- Trouble focusing objects that are far away Nearsightedness- Trouble focusing objects that are far away The eye is longer, and focuses the image in front of the retina The eye is longer, and focuses the image in front of the retina Farsightedness- Trouble focusing on objects that are near Farsightedness- Trouble focusing on objects that are near The eye is shorter than normal, and focuses the object behind the retina The eye is shorter than normal, and focuses the object behind the retina Astigmatism- Irregular curvature of cornea or lens Astigmatism- Irregular curvature of cornea or lens Doesn’t bend light correctly, making image blurry Doesn’t bend light correctly, making image blurry All can be corrected with corrective lenses All can be corrected with corrective lenses

Hearing Done by the ear Done by the ear Sound waves are collected and transferred via auditory nerve to the brain Sound waves are collected and transferred via auditory nerve to the brain 3 parts of the ear 3 parts of the ear Outer Ear- Collects and directs soundwaves to the eardrum (tympanic membrane) Outer Ear- Collects and directs soundwaves to the eardrum (tympanic membrane) Middle Ear- Contains 3 tiny bones that are vibrated by the tympanic membrane Middle Ear- Contains 3 tiny bones that are vibrated by the tympanic membrane Called the malleus (hammer), incus (anvil), and stapes (stirrup) Called the malleus (hammer), incus (anvil), and stapes (stirrup) These bones vibrate and transfer the sound to the inner ear These bones vibrate and transfer the sound to the inner ear Inner Ear- Contains the cochlea, which is filled with fluid Inner Ear- Contains the cochlea, which is filled with fluid The fluid moves and disrupts tiny hair cells, which connect to the auditory nerve The fluid moves and disrupts tiny hair cells, which connect to the auditory nerve

The Ear and Homeostasis The ear is responsible for your sense of balance The ear is responsible for your sense of balance As you move, fluid within the inner ear moves hair cells, which send information to your brain As you move, fluid within the inner ear moves hair cells, which send information to your brain Your brain interprets them and helps you maintain balance Your brain interprets them and helps you maintain balance This is also why you may get dizzy if you have an ear infection This is also why you may get dizzy if you have an ear infection

Smell Chemoreceptors in the nose collect sent particles from the air Chemoreceptors in the nose collect sent particles from the air

Taste Chemoreceptors in the mouth (a.k.a. taste buds) collect tastes and transfer them to the brain Chemoreceptors in the mouth (a.k.a. taste buds) collect tastes and transfer them to the brain Main tastes: Bitter, salty, sweet, sour, and umami Main tastes: Bitter, salty, sweet, sour, and umami Umami is a savory taste Umami is a savory taste Especially MSG in processed foods Especially MSG in processed foods Not all taste buds sense all tastes Not all taste buds sense all tastes There are not certain regions of the tongue for each There are not certain regions of the tongue for each

Touch Touch receptors in the skin feel temperature, pressure, and pain Touch receptors in the skin feel temperature, pressure, and pain Different receptors allow for feeling light touches (tickles) and harder touches (pokes or jabs) Different receptors allow for feeling light touches (tickles) and harder touches (pokes or jabs) There are more receptors in some areas than others There are more receptors in some areas than others (where are you most ticklish?) (where are you most ticklish?)

The Endocrine System A group of organs and tissues that release chemicals (called hormones) into the blood A group of organs and tissues that release chemicals (called hormones) into the blood Slower than the nervous system Slower than the nervous system Endocrine glands release the hormones and they travel to other areas of the body Endocrine glands release the hormones and they travel to other areas of the body They bond to specific cells (lock and key) They bond to specific cells (lock and key)

Major Endocrine Glands Hypothalamus and Pituitary Glands in the brain Hypothalamus and Pituitary Glands in the brain Hypothalamus receives information from the body and signals the pituitary gland to release hormones Hypothalamus receives information from the body and signals the pituitary gland to release hormones The Pituitary Gland releases hormones that regulate body functions and control the rest of the endocrine system The Pituitary Gland releases hormones that regulate body functions and control the rest of the endocrine system It also releases growth hormone which allows the body to grow It also releases growth hormone which allows the body to grow The Thyroid Gland regulates how the body uses energy (metabolism) The Thyroid Gland regulates how the body uses energy (metabolism) Located in the throat Located in the throat The Thymus Gland, located in the chest, signals the body to fight infections The Thymus Gland, located in the chest, signals the body to fight infections

More Endocrine Glands Adrenal Glands in the abdomen release adrenaline to help respond to stress Adrenal Glands in the abdomen release adrenaline to help respond to stress The Pancreas secretes insulin to control blood sugar The Pancreas secretes insulin to control blood sugar In females, ovaries release estrogen and produce egg cells In females, ovaries release estrogen and produce egg cells In males, testes release testosterone and produce sperm In males, testes release testosterone and produce sperm

The Endocrine System and Homeostasis The glands of the endocrine system respond to stimuli and release hormones The glands of the endocrine system respond to stimuli and release hormones Helps to regulate internal conditions Helps to regulate internal conditions Feedback Loops Feedback Loops Negative Feedback-The glands release hormone only when needed Negative Feedback-The glands release hormone only when needed Continually happening in the body Continually happening in the body Positive Feedback- The release of a hormone causes more to be released Positive Feedback- The release of a hormone causes more to be released Not as common Not as common Childbirth, secretion of breastmilk Childbirth, secretion of breastmilk