The HUMAN NERVOUS SYSTEM
Human Nervous System - is one of the systems in the human body that controls voluntary and involuntary processes inside and outside the body - is divided into two parts: the Central and the Peripheral Nervous Systems Korean International School Phil’s
The Central Nervous System - the control center of the body responsible for controlling, receiving, and interpreting all stimuli. - consists of the brain and the spinal cord. Korean International School Phil’s
The Peripheral Nervous System - consists of the cranial and spinal nerves that extend throughout the different parts of the body. - carries messages from and to (vice versa) the brain. Korean International School Phil’s
The two major divisions of the Nervous System Korean International School Phil’s
The Human Brain - a mass of 100 billion neurons located in the skull. - controls bodily functions and interactions with the outside world. - has four major parts: cerebrum, cerebellum, brainstem and diencephalon Korean International School Phil’s
Cerebral cortex Corpus callosum Brain stem Cerebellum different regions have different functions Cerebral cortex Functions include: planning; reasoning; language; recognising sounds and images; memory. Corpus callosum connects the brain’s right and left hemispheres Cerebellum important for coordination, precision and timing of movement Brain stem regulates heart rate, breathing, sleep cycles and emotions Credit: Mark Lythgoe & Chloe Hutton, Wellcome Images Korean International School Phil’s
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CNS: The Spinal Cord - a column of nerves from the brain to the tailbone that is protected by vertebrae of spine. - responsible for conducting impulses from the brain to the different parts of the body. Korean International School Phil’s
Neurons - also called nerve cells, are responsible for transmitting electrochemical messages to another neurons.. - consists of three major parts: dendrites, cell body and axon. Korean International School Phil’s
axon nerve endings dendrites myelin sheath cell body nucleus Korean International School Phil’s
But what happens when the signal reaches the end of the axon? neurons communicate with each other using a mixture of electrical & chemical signals nerve endings dendrites But what happens when the signal reaches the end of the axon? myelin sheath cell body an electrical signal is transmitted along the axon nucleus axon Korean International School Phil’s
signals cross between neurons at the synapse nerve endings dendrites neurotransmitter vesicle synaptic cleft receptor myelin sheath cell body the signal is transmitted to another neurone across a junction called a synapse by chemicals called neurotransmitters. nucleus axon Korean International School Phil’s
signals cross between neurons at the synapse electrical impulse triggers vesicles to move to the synapse membrane 1 synapse vesicles fuse with the membrane and release neurotransmitter into the synaptic cleft 2 nerve endings dendrites neurotransmitter diffuses across the cleft and binds to receptors on the other side 3 neurotransmitter vesicle synaptic cleft receptor myelin sheath cell body the signal is transmitted to another neurone across a junction called a synapse by chemicals called neurotransmitters. nucleus Once enough receptors have neurotransmitters bound to them, the signal is transmitted… 4 axon Korean International School Phil’s
Types of Neurons Efferent Afferent - conveys information from CNS to other parts of the body. Afferent - carries information from sensory receptors to the CNS. Korean International School Phil’s
Checking Understanding prick dilate pupil heartbeat digestion coughing salivate shivering sneezing secrete hormones Efferent Afferent Korean International School Phil’s
Group Activity 1. Ways to take good care of our nervous system. 2. Activities that disadvantages our nervous system. 3. Importance of our nervous system CCF Life Academy Foundation INC.
The NERVOUS SYSTEM - End of the lesson -