Unit 4 Homeostasis PDF

Test Hints Liam Kelly - Grade 12 Biology First Mini Quiz Test Hints - Difference of the Nervous Systems Central Nervous System - Consists of the brain and spinal cord - Integrates and processes information Peripheral Nervous System - Consists of periphera...

Test Hints Liam Kelly - Grade 12 Biology First Mini Quiz Test Hints - Difference of the Nervous Systems Central Nervous System - Consists of the brain and spinal cord - Integrates and processes information Peripheral Nervous System - Consists of peripheral nerves - Links the central nervous system to the rest of the body - Know the general system (Pathway on how to receive signals) -Know what homeostasis is (question: which of the following refers to the maintenance of the body's internal environment at a relatively constant level?) - Label a neuron Cell Body - outer layer of of the sun looking thing Dendrites - The tips of the “sun rays” (Lines) Nucleus - The middle of the sun looking thing Axons - The ovals coming off of it - What is the reflex arc - A short neuron pathway to produce involuntary reflexive behaviors - Skips brain processing and goes through the spinal cord - Motor response is generated before brain sensory input is made, which means it is a rapid involuntary response Reflex Arc Responding to Pain The Receptor: Pain Receptor on skin The Sensory Neuron: Passes impulse to interneuron The Interneuron: in spinal cord, relays impulse to motor neuron The Motor Neuron: Causes the muscle (Effector) to contract and pull away The Response: Moved the hand away from the pain -Difference between reflex arc and anything else, where does it go through in terms of of the nervous system - Instead of going through the brain, and the brain integrates a response, it goes right through the spinal cord, not including the brain integration and response, and just automatically retracting the muscle involuntary -Know the spine - Should know what milenation does -provides protection and increases the speed of contraction - Need to know what schwann cells are and glial cells Schwann Cells -made out of myelin sheath -the myelin sheath is used for protection and to increase the speed of contraction Glial Cells - Support cells - Nourish neurons, remove wastes, defends against infection - Need to know what are neurons and neurotransmitters are Neuron - Cell that carries electrical signals (Stimulus) throughout the body - Main building block of the nervous system - Allows communication between the brain, spinal cord, and rest of body to occur - Organized into tissue called nerves Neurotransmitters - Chemical messenger that aids in transmitting signals (Stimuli) between neurons - Central Nervous System vs Peripheral Nervous System Central Nervous System - Consists of the brain and spinal cord - Integrates and processes information Peripheral Nervous System- Consists of peripheral nerves - Connects the CNS to the rest of the body - Efferent vs Afferent Efferent - Signals or pathways that carry information away from the central nervous system to effectors - Help the body regulate temperature, etc Afferent - Signals or pathways that carry information toward the central nervous system, from receptors - Help the body detect changes in the environment Somatic System - Voluntary system - Parasympathetic vs Sympathetic Autonomic Systems - All Autonomic pathways are involuntary Parasympathetic Autonomic System - Part of the involuntary nervous system - Referred to as the rest and digest response - Calms the body down Sympathetic Autonomic System - Part of the involuntary nervous system - Referred to as the fight or flight response - Increases things in the body - The brain, and what each component is responsible for Frontal Lobe - Front portion of the brain - General Motor - Responsible for planning and personality Parietal Lobe - Middle portion of the brain - Responsible for sensory association Occipital Lobe - Back portion of the brain - Responsible for visual association and eye sight Temporal Lobe - Side portion of the brain - Responsible for the senses, smell, hearing, seeing also facial recognition - Should know what motor and sensory neurons are Motor Neurons - Located in the spinal cord and synapse with muscle fibers to make them contract - Carries information from the Central Nervous System to the effectors: Muscles, Glands, Other Organs Sensory Neurons - Located in the peripheral nervous system - Also known as afferent neurons - Located in clusters called ganglia - Receives stimuli from the environment and generates a nerve impulse - Order the action potential, with numbers to Step 1 - The action potential begins at -70mv - A Strong enough stimulus jolts up to -50 mv overtaking the threshold Step 2 - Voltage gated sodium channels are open - Sodium runs down the gradient into the axon (Diffusion) - The sodium running into the cell depolarizes the membrane - More positive charges are in the membrane making it +40 mv Step 3 - Voltage gated sodium channels close due to membrane potential change - Voltage gated potassium channels open at +40 mv - Potassium moves down the gradient and exits the axon (Cell) - The membrane then becomes hyperpolarized down to -90 mv - The Sodium is leaving, which polarizes the cell Step 4 - Voltage gated Potassium channels close - Sodium Potassium pump and naturally occurring diffusion restores the resting membrane potential of -70 mv - The time from when the cell is between -90 and -70 is called the refractory period - When the cell is back up to -70 mv, it is ready to be stimulated again - Should know what the neurotransmitters do (Dopamine) (Serotonin) (GABA) Dopamine: Pleasure Serotonin: Mood Gaba: Calming - Should know synapses (How neurotransmitters travel, from the pre to the post neuron) - The axon end meeting with the dendrites - Neuron to Neuron - Neurotransmitters travel across the synapse - This is how neurons communicate with one another - Need to know the difference between positive and negative feedback Positive Feedback - When the body amplies or intensifies stimulus rather than reducing it - We are not reversing the change, which means we don't want to go back to normal - A good example is child birth, as we want to birth the baby, not go back to normal Negative Feedback - When there is change and you reverse it back to normal - An example is if you take 3 steps forward, and it is negative feedback, you must take 3 steps back to go back to normal - You reverse the actual stimulus to normal, reversing the change in the body \