1. What’s Next in Biology Class?

2. Optical Illusion 1 Optical Illusion 12

5. Human Body Unit Chapter 35 – Introduction to body systems and Nervous System

6. Organization Cells: basic structures of life that specialize to perform a function Tissues: group of cells that performs certain function Epithelial: glands and tissues that form linings Epithelial: glands and tissues that form linings Connective: support for the body and connect parts Connective: support for the body and connect parts Nervous: transmit nerve impulses Nervous: transmit nerve impulses Muscle: with bones, enables body to move Muscle: with bones, enables body to move Organs: groups of tissues working together for a function Organ systems: Group of organs that perform related functions

7. 4 Types of Tissue

8. Why? Homeostasis Organisms need to keep internal conditions relatively constant despite changes in their external environments

9. 35.1 Human Body Systems (p892-893) SystemStructuresFunction NervousIntegumentarySkeletalMuscularRespiratoryCirculatoryDigestiveExcretoryEndocrineReproductiveLymphatic/immune

10. Nervous System

12. Organization Nerve cells are called neurons: Impulses are the electrical signals carried from neuron to neuron. Impulses are the electrical signals carried from neuron to neuron. Dendrites branch to the cell body and carry messages to other cells. Dendrites branch to the cell body and carry messages to other cells. Axons carry impulses away from the cell body. Axons carry impulses away from the cell body. Synapses are the spaces between 2 neurons. Synapses are the spaces between 2 neurons. The sodium potassium pump is the mechanism by which impulses are carried from cell to cell The sodium potassium pump is the mechanism by which impulses are carried from cell to cell

13. The Nerve Impulse A reversal of charges is created across cell membranes. Resting potential is changed to action potential when an impulse from a neuron is stimulated by another neuron or the environment The threshold is the minimum required stimulus to produce an impulse. Neurotransmitters are chemicals used by neurons to transmit an impulse across synapses.

14. Organization (cont.) Related neurons form nerves and collectively form the CNS and PNS Central nervous system Central nervous system Spinal Cord Brain Meninges and cerebrospinal fluid protect the CNS

15. Spinal Cord Sensory neurons carry impulses from receptors to the spinal cord Motor neurons carry impulses from the spinal cord to the effectors Association neurons maintain neural connections within the spinal cord

17. Brain Cerebrum Largest portion that is further divided into hemispheres and then 4 lobes Largest portion that is further divided into hemispheres and then 4 lobes Controls motor and sensory activities Controls motor and sensory activitiesCerebellum Coordinates muscle activity Coordinates muscle activity Brain stem Connects cerebrum with the spinal cord Connects cerebrum with the spinal cord

18. Brain stem Midbrain: controls reflexes Medulla oblongata: nerve relay station and control center Pons: relays messages between cerebrum and cerebellum Thalamus: directs incoming sensory impulses (not smell) Hypothalamus: helps maintain chemical homeostasis

19. Brain Structure Brain tour Brain tour Quiz

20. Peripheral nervous system Sensory division: transmits impulses from senses to CNS Motor division: transmits impulses from CNS to muscles or glands Somatic NS: regulates activities that are under conscious control. EX: Autonomic NS: regulates involuntary activities. EX: Sympathetic and parasympathetic nervous systems work together to control homeostasis Sympathetic and parasympathetic nervous systems work together to control homeostasis