1. Respiratory System Recap

2. Gas Exchange Alveoli are tiny sacs that fill with air to
allow diffusion of gas
Many (millions of) alveoli provide a large
total surface area for greater absorption
A thin, single layer of flattened cells are on the wall of each alveolus to decrease the distance that gases need to diffuse across
A dense network of capillaries (tiny blood vessels) surrounding the alveolus to remove CO2 from brought into from rest of body and to transport O2 to rest of the body
Hemoglobin, the protein found in red blood cells, pick up O2 from the alveoli to transport to the rest of the body

3. Diffusion!? Whas dat?
Diffusion: movement of molecules from an area of high concentration to an area of low concentration(i.e. with the concentration gradient); type of passive transport

4. INHALE our lungs fill with oxygen, which increases the concentration of O2 in alveoli, low concentration of O2 in capillaries
capillaries contain a high concentration of CO2, low concentration of CO2 in alveoli
Oxygen moves from the alveoli into the capillaries (high to low) and CO2 moves from the capillaries (high to low) into the alveoli and out your lungs which empty EXHALE

5. Nervous System

6. What is the Nervous System?
The control system that enables animals to detect a stimulus and coordinate a response
Stimulus: changes in the body that are detected by your body
Response: your body’s reaction to this stimulus

7. How Does Communication Occur?
Neurons
Nerve cells are called neurons
The functional unit of the nervous system
Use electrical signals called impulses to communicate with other cells
Nerve
a bundle of neurons

8. Parts of A Neuron Dendrites Axon Myelin Sheath
carry impulses from outside
the cell into the cell body
Axon
carries the impulse away from
the cell body towards neighbouring cells
- conducting wire
Myelin Sheath
sometimes covers the axon, speeds up transmission of the nerve impulse
Draw parts of neuron on the board

9. Parts of A Neuron Terminal knobs Neurotransmitters Synapse
attach the neuron to other cells (other neurons or target cells)
Neurotransmitters
Chemical released by the terminal knobs that carries the impulse from 1 neuron to another
Synapse
connection between axon of one neuron and dendrites of an adjacent neuron
Direction of impulse is always from the dendrites to the terminal knobs

10. Types of Neurons Sensory neurons Motor neurons Interneurons
carry impulses from sensory receptors (eye, ear, nose, skin, tongue) to the brain
Motor neurons
carry impulses from the brain or spinal cord to muscles for movement or glands for hormone secretion
Interneurons
link the sensory and motor neurons in the brain and spinal cord

11. Parts of The Nervous system
Central Nervous System
Brain
Spinal Cord

12. Parts of The Nervous System
Peripheral Nervous System
Somatic nerves
(somatic nervous system)
Voluntary
Sensory
Motor
Autonomic Nerves (autonomic nervous system)
Involuntary
Sympathetic
Parasympathetic

13. Somatic Nervous System
Motor neurons under conscious control
Voluntary control of body movements by the skeletal muscles
All sensory neurons
Sensory reception of external stimuli (touching, hearing, seeing, smelling, tasting)

14. Autonomic Nervous System
Motor neurons that are unconsciously controlled
Eg. Heart, body temp, blood pressure, pupil dilation, gland secretions
Broken down into
Sympathetic
Prepares body for danger
Parasympathetic
Returns body to normal relaxed state after stress

15. Sympathetic and Parasympathetic Nerves
Parasympathetic…think parachute

16. The Endocrine System

17. The Endocrine System
The endocrine system sends messages to control and coordinate the body’s internal environment
These messages are sent by chemicals that are called hormones, which are directly released into the bloodstream
Similar to the nervous system, but uses hormones to deliver these messages rather than electrical impulses

18. Hormones
chemical released into the bloodstream by one type of cell that has an effect on another type of cell in a different location
help regulate and coordinate the functions of almost all organ systems
important in maintaining a constant internal environment
control many developmental changes

19. Glands Organ that manufactures and secretes hormones
Pituitary gland and Hypothalamus control the hormone secretions of several other glands in the body
Pituitary gland secretes the most hormones in the body
The means by which these hormones are released into the bloodstream

20. Activity Sensory Receptors Pg 107 # 1-5 (Nelson Text)
Homework
Activity Sensory Receptors Pg 107 # 1-5 (Nelson Text)