Human Regulation
Regulation: HOMEOSTASIS! The life process by which the human body responds to its changing (inside and outside) environment. Constant adjustments made as a result of the changing environment help maintain… HOMEOSTASIS!
Nervous System Endocrine System Regulation: Nervous System Endocrine System
Main Function: The Nervous System Responds to internal and external stimuli by controlling and coordinating functions throughout the body Our nervous system allows us to feel pain and react to it!
brain, spinal cord, nerves and sense organs The Nervous System Consists of: brain, spinal cord, nerves and sense organs Sense Organs: Eyes, Skin, Ears, Nose & Tongue
2 Divisions of the Nervous System Peripheral Nervous System (PNS) Central Nervous System (CNS) nerves extending throughout body Gathers & delivers info to and from the CNS brain & spinal cord Main control center of body
Peripheral Nervous System (PNS) All of the Organs the PNS controls!!!
The Neuron (Nerve Cell) Neurons carry messages called impulses back and forth between the peripheral nervous system and the central nervous system.
Impulse in a Neuron signal direction ONE WAY dendrites nucleus terminal branches signal direction ONE WAY cell body synapse (space) axon
Impulse in a Neuron synapse (space) axon
Axon is coated with insulation made of myelin cells (Lipids) signal direction With myelin…signal hops from node to node at 330mph! (vs. only 11mph) Multiple Sclerosis immune system attacks myelin coating loss of signal myelin coating
Because neurons never touch, chemical signalers called neurotransmitters must travel through the space called synapse between two neurons. synapse
The message is transferred when RECEPTORS receive neurotransmitters. Synapse (gap)
Receptors: Protein Shape Specific! Drugs/Poisons Stimulants - Speed up production and release of neurotransmitters (Caffeine) Depressants – block formation of neurotransmitters. (Pain Killers)
Which cell (X or Y) shows the receptor molecules? What would a drug that interferes with communication between these two cells look like?
Sensory Neuron Interneuron Motor Neuron Types of Neurons Synapse Muscle Contracts Motor Neuron Sensory Neuron
3 Types of neurons sensory neuron (from senses) receive stimulus interneuron CNS motor neuron (to effector – muscle/gland) produces response
Axons branching out to muscle fibers Motor Neurons Axons branching out to muscle fibers
Fun facts about neurons Most specialized cell in animals Longest cell blue whale neuron 10-30 meters giraffe axon 5 meters human neuron 1-2 meters Nervous system allows for 1 millisecond response time
Simplest Nerve Circuit – Reflex Arc 2 3 1.Receptor 2.Sensory Neuron 3.Interneuron 4.Motor Neuron 5.Effector 1 4 5
A reflex is an involuntary response that is processed in the spinal cord not the brain. Reflexes protect the body before the brain knows what is going on. *faster because they don’t have to travel to brain! Reflex Arc
Watch Again!!! 2 3 1 4 5 1.Receptor 2.Sensory Neuron 3.Interneuron 4.Motor Neuron 5.Effector 1 4 5
The Brain: Where do the impulses go??? Spinal Cord Cerebellum Cerebrum Medulla Oblongata
Brain - Receives 20% of blood pumped by heart - Is the major user of glucose in the body What does the brain use glucose for? Consists of 3 Parts: Cerebrum Cerebellum Medulla (Brain Stem)
Higher Brain: Cerebrum 2 hemispheres: left controls the right side of body right controls the left side of body
Cerebrum Functions Regions specialized for different functions 4 Lobes 1. frontal speech, control of emotions 2. temporal smell, hearing 3. occipital vision 4. parietal speech, taste reading frontal parietal temporal occipital
Cerebellum Found in back part of head under the cerebrum coordination of smooth, steady and efficient MOVEMENT BALANCE, equilibrium and posture If damaged can result in jerky movement, loss of coordination and balance
Brain Stem (Medulla) Medulla Oblongata basic body functions breathing heartbeat digestion swallowing vomiting coughing blinking HOMEOSTASIS
CNS Protection Bone: Skull, Vertebrae Cartilage disks found between vertebrate absorb shock Meninges (protective membrane) cover the brain and spinal cord Cerebral Spinal Fluid surrounds Brain and Spinal Cord. Acts like a watery cushion!
When homeostasis is distrupted!
Cerebral Palsy: A group of birth disorders characterized by disturbances of motor functions.
Polio: A viral disease of the CNS that can cause paralysis. Prevented by immunization!
Meningitis – an inflammation, caused by bacteria, of the membranes that surround the brain and spinal cord. Can be fatal. Symptoms: severe headache, stiff neck
Concussion: The Brain is a soft organ protected by your hard skull surrounded by spinal fluid (cushion that keeps your brain from banging into your skull) Hard hit/fall=Brain crashes into your skull=Damaged Brain