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What is an Animal? . Characteristics of All Animals 1. Animals are Multicellular 2. Animals are Eukaryotic 3. Animals are Heterotrophs 4. Animal cells lack cell walls . Evolutionary/Developmental Milestones in Animals. Cell specialization and levels of organization
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What is an Animal? Characteristics of All Animals 1. Animals are Multicellular 2. Animals are Eukaryotic 3. Animals are Heterotrophs 4. Animal cells lack cell walls
Evolutionary/Developmental Milestones in Animals • Cellspecialization and levels of organization • Development of body symmetry and segmentation • Development of an internal body cavity and tissue layers
Cell Specialization Cells throughout a multicellular organism can develop in different ways to perform different tasks.
Body Segmentation Segmentation of the body allows development of various specialized limbs, such as antennae, pincers, walking legs, claws, wings, etc. Cephalization is the concentration of nervous tissues in one location which eventually produces a head region with sensory organs and a brain.
Tissue Layers & Body Cavity A body cavity, called a coelom, increases the efficiency of food intake and waste removal.
ANIMAL BODY SYSTEMS Body systems are all interrelated and work together to perform their functions in animals. Body systems can be organized and studies by these functions: • REGULATION: Excretory & Nervous Systems • NUTRIENT ABSORPTION: Respiration, Digestion, & Circulatory Systems • DEFENSE: Immune, Integumentary, Lymphatic, Skeletal, & Muscular Systems • Reproduction: Reproductive & Endocrine Systems
FACT OF THE DAY: * Messages travel along the nerves as electrical impulses. They travel at speeds up to 248 miles per hour!
Nervous SystemThe nervous system maintains homeostasis by controlling and regulating all other parts of the body. Regulation requires homeostasis- the ability of the body or a cell to seek and maintain stability within its internal environment when dealing with external changes
Function of The Nervous System • Sensory • Detect change inside and outside of body • Interpret • Interpret the change with the brain and spinal cord • Response • Control and coordinate functions throughout the body • Respond to internal and external stimuli
Evolutionary Trends of the Nervous System Complex Simple
Structure of Nervous System • Neuron - Message sending unit of the nervous system • Cell body- the largest part of the neuron; contains the nucleus and organelles • Axon - Carries nerve impulse away from the cell body • Dendrite - Carries nerve impulse to the cell body
dendrite muscle tissue Axon cell body TYPICAL MOTOR NEURON synapse Impulse in a Neuron cell body
Because neurons never touch, chemical signalers called neurotransmitters must travel through thespace called synapse between two neurons to continue the electrical signal (impulse). Neurotransmitters (pink spheres) The message is transferred whenRECEPTORSreceive neurotrans-mitters. Synapse (gap)
How Impulses Are Carried • Flow of Impulse: dendrite nucleus axon jumps synapse next dendrite
Types of Neurons • Sensory - Conduct impulses from sense organs to the brain ( CNS) • Motor - Conduct impulses from brain/spinal cord (CNS) to muscle/organs • Interneurons - Conduct impulses within the brain/spinal cord (CNS)
Divisions of the Nervous System • Central Nervous System (CNS) • Peripheral Nervous System (PNS)
Divisions of the Nervous System • Central Nervous System – Brain and spinal cord • Integrates information • Derived from the dorsal nerve cord
Main Parts of the Brain • Forebrain = • Cerebrum • Controls muscles • Jobs that are voluntary • It stores messages • Studying • Thalamus, Hypothalamus (biological clock) • Controls thought, reason, and the senses • Controls homeostasis – temperature, hunger, thirst, flight or fight response • Midbrain (middle region of brainstem) • Regulation of auditory and visual reflexes (peripheral vision) • Hindbrain = • Medulla Oblongata & Pons • Controls heartbeat, breathing and blood pressure • Jobs that are involuntary (breathing, swallowing, vomiting, digestion) • Cerebellum: • Makes movements more smooth and graceful; balance (hand-eye coordination) • Jobs are involuntary http://faculty.washington.edu/chudler/stm0.html
Reflexes • Controlled by the spinal cord • They are involuntary • They happen very quickly • Take place without the brain receiving the message • They protect you by triggering an involuntary response to stimuli (stepping on a tack)
Divisions of the Nervous System 2. Peripheral Nervous System – All other nerves • Sensory division (impulses from sense organs to CNS) • Motor division (impulses from CNS to muscles) • Somatic NS (regulates voluntary activities - lift a finger, wiggle a toe) • Autonomic NS (regulates involuntary activities – heart rate, sweat glands, muscles in your digestive tract) • Parasympathetic – “Rest and Digest” • Sympathetic – “Fight or Flight”; pupil dilates
Sympathetic – “Fight-or-flight” • Response to unusual stimulus • Takes over to increase activities • Increases heart rate, blood pressure, blood glucose levels, dilates the bronchioles of the lungs, and dilates the pupils • Remember as the “E” division = Exercise, excitement, emergency, and embarrassment Autonomic Functioning
Sympathetic – “Fight-or-flight” • The effects of sympathetic nervous system activation continue for several minutes until its hormones are destroyed by the liver. • Helps explain why we need time to “calm down” after an extremely stressful situation. Autonomic Functioning
Parasympathetic – Housekeeping activites • “Resting and digesting” system • Chiefly concerned with promoting normal digestion and elimination of feces and urine and with conserving body energy • Heart rate, blood pressure, and respiratory rates are at low normal levels; pupils are constricted; skin is warm; digestive tract is actively digesting food • Remember as the “D” division - Digestion, defecation, and diuresis (urination) Autonomic Functioning
Levels of Organization Neurons Nerves Brain & Spinal Cord Nervous
CoackroachBeatbox TED Video • http://www.ted.com/talks/the_cockroach_beatbox.html
Lobes of the cerebrum Processes sensory impulses from the body Reasoning, logic, language, etc. Visual images Hearing, smell, memories
Logic/reasoning Speech
Language and Speech – strokes, tumors, injuries • Broca’s Area: • Primary motor cortex in the frontal lobe that controls muscles • Damage to area means you can understand language but are unable to speak it • Responsible for speech generation • Ex – stroke patients • Wernicke’s Area: • The posterior part of temporal lobe • Damage to area means you can speak but unable to comprehend speech • Responsible for hearing speech http://www.hulu.com/watch/339577/greys-anatomy-one-step-too-far Go to 21 min mark
Interaction with othersystems for Regulation • Bones of the skeletal systemprotect the spinal cord and brain. • The brain controls heart rate, blood pressure, and breathing via the circulatory and respiratory systems. • Glands in the brain control the release of hormones of the endocrine and reproductive systems. • The brain controls muscles both in digestion and movement.
Reticular Formation – neurons in the core of the brainstem (midbrain -arousal, pons & medulla-sleep) • Sleep & wakefulness produces patterns of electrical activity in the brain • Recorded as an ElectoEncephaloGram(EEG) • Most dreaming duringREM(rapid eye movement sleep)
Did You Know… • Bottlenose Dolphins swim while sleeping, rising to the surface to breathe air regularly! • Their forebrain is divided into two halves. Since they sleep with one eye open and one closed they are able to sleep with one brain hemisphere at a time.
The amygdala is responsible for determining what memories are stored and where the memories are stored in the brain The hippocampus sends memories out to the appropriate part of the brain for long-term storage and retrieves them when necessary. Damage to this area of the brain may result in an inability to form new memories.
Lobotomy… • Phineas Gage, 1848 – was a loving, caring father until the accident and then became detached, impatient & erratic • Later in the 20th century, surgical procedures were done to remove portions of the frontal lobe in attempt to cure severe behavioral and psychiatric behaviors
Fun Facts • A human body contains more nerve cells than there are stars in the Milky Way • Neurons are the largest cell in the body and do NOT undergo mitosis • Nerve impulses move at 100 meters per second or more • Longest axon of a neuron is 15 ft! (in the giraffe)