Notes: Immune System, Integumentary System, and Nervous System

1. Notes:Immune System, Integumentary System, and Nervous System

2. Immune SystemMajor Function-protection mechanism designed to defend you against millions of bacteria, microbes, viruses, toxins and parasites that would love to invade your body. • Pathogens- disease-causing agents • White blood cells - protect the body against disease by seeking and destroying pathogens, and activating cells that make antibodies • Antibodies – specialized protein that help destroy pathogens • Immunity– ability to destroy pathogens before they can cause disease

3. Antibiotics versus vaccines?? Antibiotics Vaccines • Fights bacterial infections • Prevents viral infections

4. IntegumentarySystem • Skin, nails, hair • Protects internal organs, keeps foreign substances out, keeps body from drying out • Skin made up of 3 layers: • The Epidermis – outermost layer where growth of skin takes place • The Dermis – give skin elasticity and strength • The Hypodermis – cushion (fat)

6. Nervous System Two Major Functions-1. Orders are sent from the brain to body organs and tissues along Motor neurons.2. Information about the body's condition or the environment is sent to the brain along sensory neurons. This information is obtained using the 5 senses. • Brain – sends orders to organs and tissues along the neurons • Neurons- carries the orders from the brain, carries messages from the senses • Senses: Sight, Hearing, Touch, Taste and Smell- Receives messages about the body’s condition or the environment and sends them to the brain

7. Brain • Structure: • The brain has three main parts: the cerebrum, the cerebellum, and the brain stem (medulla) Weight - approximately 3 pounds

8. Additional Structures of the Brain • Cerebellum – • Balance, Posture • Brain Stem – • Motor and sensory pathway to body and face

9. Function of Each Part of the Cerebrum • Frontal Lobe - Behavior, Abstract thought processes, Problem solving, Attention, Creative thought, Some emotion, Intellect, Reflection, Judgment, Initiative, Inhibition, Coordination of movements, Generalized and mass movements, Some eye movements, Sense of smell, Muscle movements, Skilled movements, Some motor skills, Physical reaction, Libido (sexual urges) • Parietal Lobe – Sense of touch (tactile sensation), Appreciation of form through touch (stereo gnosis), Response to internal stimuli (proprioception), Sensory combination and comprehension, Some language and reading functions, Some visual functions • Occipital Lobe – Vision and Reading • Temporal Lobe – Auditory memories, Some hearing, Visual memories, Some vision pathways, Other memory, Music, Fear, Some language, Some speech, Some behavior and emotions, Sense of identity

10. The Nervous System - Nerves • Function of the nerves - provide a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. (Below: axon) • Each nerve is a cordlike structure that contains many axons. These axons are often referred to as “fibers”. The axons are bundled together into groups and wrapped in connective tissue. (Right: Nerves Pictured in Yellow)

11. The Neuron (Nerve cell) • A neuron has a large cell body that contains the nucleus, threadlike extensions called dendrites, and an axon.

12. How a Nerve Impulse Travels • For a nerve impulse to be carried along at a synapse, it must cross the gap between the axon and the next structure. The axon tips release chemicals that carry the impulse across the gap.

13. Vision • You eyes respond to the stimulus of light. They convert that stimulus into impulses that your brain interprets, enabling you to see.

14. Vision • Light coming from an object enters your eye and is focused by the lens. The light produces an upside-down image on your retina. Receptors in your retina then send impulses to your cerebrum, which turns the image right-side up.

15. Eye Sclera – white part of the eyeball (outer coat) Cornea – where light strikes, protection Pupil – an opening in the iris where light enters Lens – focuses light Iris – colorful part of eye that changes shape to control light Retina – changes the light received into nerve signals for the brain Optic nerve – carries messages from eye to brain Vitreous – 2/3 of the eye’s volume, jellylike

16. Hearing • Your ears are the sense organs that respond to the stimulus of sound. Ears convert the sound to nerve impulses that your brain interprets.

17. Balance • The semicircular canals in the inner ear control balance • Vibrations from the fluid in the canals sends nerve signals to the brain • If a sense of balance is lost, impulses are sent back to the muscles to help you restore your balance • Ever been dizzy or sea sick?

18. The Five Senses