Nervous System SAQs.docx

The Human Nervous System SAQs - What are the 2 parts of the nervous system?  1. The central nervous system and the peripheral nervous system  - What makes up the central nervous system? 1. The brain and spinal cord  - What makes up the peripheral nervous system?  1. Nerves that carry...

The Human Nervous System SAQs - What are the 2 parts of the nervous system?  1. The central nervous system and the peripheral nervous system  - What makes up the central nervous system? 1. The brain and spinal cord  - What makes up the peripheral nervous system?  1. Nerves that carry impulses to and from the CNS  - What is the functional subunit of the nervous system? 1. Nerve cell/ neuron  - What are the 3 neuron types and their functions?  1. **Sensory Neurons,** carry impulses from the receptors to the CNS. **Motor Neurons**, carry impulses away from the CNS to the effectors. **Interneurons, ** carry impulses within the CNS. - What is the function of the cell body in a neuron?  1. receives impulses from the dendrites, contains nucleus to control neuron activities, produces neurotransmitter chemicals  - What are the functions of the myelin sheath in the neuron?  1. Insulates the neuron, speeds up electrical transmissions  - What is the synapse?  1. region where two neurons come into close contact. - What is the Synaptic cleft?  1. the physical gap between two neurons - What are neurotransmitters?  1. chemicals released into the synapse to carry signals from one neuron to the next  - What part of the brain controls involuntary actions such as breathing or heart rate?  1. The medulla oblongata  - What is the function of the Hypothalamus?  1. Controls overall homeostasis  - What is a stimulus?  1. a change in the environment that causes a reaction - What is Reflex Action?  1. Involuntary response to a stimulus.  - Why is reflex action important to humans?  1. Protects the body against harmful and unexpected stimuli  - Give 3 examples of reflex actions  1. Eye blink, pupil size alteration, removal of hand from hot object.  - What is the Reflex Arc?  1. The specific nerve pathway involved in responding to a stimulus.  - Name a disorder of the nervous system and state its symptoms, cause and treatment.  1. Disorder: Parkinson's Disease  Symptoms: persistent trembling of the hands and legs, muscle stiffness, difficulty walking  Cause: failure to produce dopamine  Treatment: physiotherapy and dopamine secreting cells are transplanted into the brain. - Which part of the spinal cord consists mainly of cell bodies? 1. grey matter  - Which part of the spinal cord consists mainly of axons? 1. white matter.  - What is the function of the dorsal root in the spinal cord? 1. carries impulses towards the CNS from receptors. - Which part of the spinal cord contains cerebrospinal fluid? 1. the central canal