Unit 5: Body Systems Add the new notes to your table of contents, and then turn to the next clean page and set up your title and date

Levels of Organization Recall that there are 6 characteristics of living things, we are focusing on two for Unit 5: all living things are made up of cells all living things are organized

Add tissue to your index Tissues are groups of similar types of cells in multicellular organisms that work together to carry out specific tasks Humans, like most other animals, have four main types of tissue: muscle, connective, nervous, and epithelial Add tissue to your index

made up of layers of tightly packed cells that line the surfaces of the body examples of epithelial tissue include the skin, the lining of the mouth and nose, and the lining of the digestive system made up of many different types of cells that are all involved in supporting and binding other tissues of the body examples include tendon, cartilage, and bone. Blood is also classified as a specialized connective tissue made up of bands of cells that contract and allow movement made up of nerve cells that sense stimuli and transmit signals nervous tissue is found in nerves, the spinal cord, and the brain

Add organs and organ systems to your index Organs are groups of different tissues working together to perform a particular job. Organ systems are groups of different organs that work together to complete a series of tasks. Add organs and organ systems to your index

Multicellular organisms usually have many organ systems that work together to carry out all the jobs needed for the survival of the organism.

Right Now Copy down your homework Take out your homework Today’s Plan Review homework Continue notes on Body Systems

Place this tape-in into your notebook and label each level of organization

Systems may interact with other systems Systems may have subsystems and be part of larger complex systems

The Circulatory System includes the heart, blood vessels and blood transports oxygen, hormones and nutrients to the body’s cells moves waste and carbon dioxide away from cells

The Excretory System includes the kidneys and bladder removes water, salts, and waste products from blood and body controls pH controls water and salt balance

The Digestive System includes the stomach, small intestine, and large intestine digests foods absorbs nutrients, minerals, vitamins, and water

The Respiratory System includes the trachea, larynx, pharynx, and lungs brings air to sites where gas exchange can occur between the blood and cells (around the body) or blood and air (in the lungs)

The Muscular System includes cardiac (heart) muscle, skeletal muscle, smooth muscle, and tendons involved in movement and heat production

The Nervous System includes the brain, spinal cord, and nerves collects, transfers, and processes information

The Endocrine System includes all of the glands of the human body produces hormones regulates metabolism, growth and development, sleep and mood

Homeostasis What is the first sign that you may be sick?

Homeostasis The systems in your body work together to maintain homeostasis Homeostasis is the ability to maintain constant internal conditions when outside conditions change

System Interactions Nutrients are processed when the digestive, muscular, and circulatory systems work together. The respiratory, circulatory, muscular, and digestive systems work together and process oxygen and move wastes from the body. The nervous system communicates with the muscular and skeletal systems and coordinates movement and responds to stimuli.

Unit 5 B: Signals in Your Body Add the new notes to your table of contents, and then turn to the next clean page and set up your title and date

Add sensory receptors to your index Sensory receptors are specialized cells to detect specific stimuli Interoceptors – detect stimuli inside the body Include receptors for blood pressure, blood volume, and blood pH Directly involved in homeostasis Exteroceptors – detect stimuli outside the body Include receptors for taste, smell, vision, hearing, and equilibrium Add sensory receptors to your index

Types of Sensory Receptors Chemical receptors – respond to chemicals Taste, smell, blood pH Photo receptors – respond to light energy Vision (light) Mechanical receptors – stimulated by mechanical forces Hearing, gravity, motion, body position

Thermoreceptors – stimulated by changes in temperature Located in the hypothalamus (region of brain) and skin Nociceptors (Pain receptors) – free nerve endings that are stimulated by chemicals released by damaged tissue Alert us to possible danger

How Sensation Occurs There are three steps to interpreting sensation: Detection occurs when environmental changes stimulate sensory receptors Sensation occurs when nerve impulses arrive at the cerebral cortex of the brain Perception occurs when the brain interprets the meaning of stimuli The cerebral cortex plays a key role in memory, attention, perception, awareness, thought, language, and consciousness

We are aware of a reflex action when sensory information reaches the brain The brain integrates this information with other information received from other sensory receptors

https://www.youtube.com/watch?v=-QUphgFZE3s

Sense of Taste Taste buds contain chemoreceptors and are located primarily in the tongue Different receptors exist for salty, sour, bitter, sweet tastes and umami (savory)

How does the Brain Receive Taste Information? Detection – food makes contact with your taste buds Sensation – three different nerves in your tongue send signals to your brain Perception – your brain interprets these signals and tells you what you are tasting

http://ed.ted.com/lessons/how-do-we-smell-rose-eveleth

Sense of Smell 80-90% of what we perceive as taste is actually due to smell Olfactory cells Chemoreceptors are located high in the nasal cavity

How does the Brain Receive Odor Information? Detection – during respiration scent molecules enter your nose Sensation – nerve fibers in your nose send signals to your brain via the olfactory tract Perception – your brain determines what you are smelling or an odor’s “signature”

https://www.youtube.com/watch?v=Mbmt-6o-Bp0

Sense of Vision Vision requires the work of the eyes and the brain It is believed that at least 1/3 of the cerebral cortex takes part in processing vision

How does the Brain Receive Sight Information? Detection – light enters the eye, it is focused on photoreceptors in the retina Sensation – signal is sent from optic nerve to the visual cortex Perception – your visual cortex deciphers the image

https://www.youtube.com/watch?v=2U57tFpOLYI

Sense of Hearing The ear has two sensory functions- hearing and balance (equilibrium) Sensory receptors for both of these are located in the inner ear Each consists of hair cells with stereocilia (long microvilli) that are sensitive to mechanical stimulation (mechanoreceptors)

How does the Brain Receives Sound Information? Detection – sound waves enter the auditory canal and your ear drum vibrates Sensation – the vibrations send signals to your auditory cortex Perception – your brain interprets the sound

https://www.youtube.com/watch?v=hSSnIZrk0Fg

Sense of Touch You probably think of the sense of touch as relating to your skin, after all, you have about 5 million sensory nerve receptors in your skin When the touch, pain or heat sensors in your skin are stimulated, they send electrical pulses to your neurons, special cells that relay electrochemical impulses 

How does the Brain Receive Feeling Information? Detection – contact is made with sensory receptors Sensation – sensory receptors send signals to spinal cord Perception – brain receives and translates signal from spinal cord to determine feeling (touch, pain, heat, etc.)