science 3rd

• Central Nervous System - main processing center for the entire nervous system
• two main components of cns - brain and spinalcord
• brain - organ located within the skull that functions as organizer and distributor of information for the body.
• three main parts of brain: Cerebrum, Cerebellum, Brain Stem
• Cerebrum - large, upper part of the brain that controls activity and thought
• Cerebellum - the part under the cerebrum that controls posture. balance, and coordination
• Brain Stem - the part that connects the brain to the spinal cord and controls automatic functions such as breathing, digestion, heart rate, and blood pressure.
• Spinal Cord - serves as a channel for signals between the brain and the rest of the body, and controls simple musculoskeletal reflexes without input from the brain.
• Peripheral Nervous System - connects the central nervous system to the organs and limbs.
• two main divisions of pns: somatic nervous system and autonomic nervous system
• Somatic Nervous System - this system is associated with the voluntary control of body movements
• two main parts of somatic: spinal nerves and cranial nerves
• spinal nerves - the nerves that carry motor and sensory signals between the spinal cord and the body.
• Cranial Nerves - the nerve fibers that carry information into and out of the brain stem
• Autonomic Nervous System - This system is associated with the involuntary control of body movements
• two divisions of autonomic: sympathetic and parasympathetic
• Sympathetic - it is activated when the body is in a dynamic role or stress. (e.g.. increased heart rate and breathing, dilation of pupil, sweating, etc.)
• Parasympathetic it maintains body functions and restores the body to normal or relaxed mode.
• The basic unit of the nervous system is the nerve cell. Nerve cells are called neurons
• There are twelve to fourteen billions of neurons in one part of the brain alone. A neuron has a cell body containing the nucleus
• Dendrites carry impulses towards the cell body. A cell may have as many as 200 dendrites
• A single dendrite can be over one meter long.
• Axons carry impulses away from the cell body.
• Axons pass impulses to the dendrites of other neurons or cell body of muscle cells
• Axons can be grouped together into cable-like bundles called nerves
• endocrine system contains a group of glands that releases hormones into the body
• Pituitary - at the base of thee brain
• Pituitary - stimulates growth, and controls the functions of other glands
• Thyroid - regulates body metabolism, and causes storage of calcium in bones. It is located below the voice box
• Parathyroid - controls the calcium levels in your body, and normalizes bone growth. It is in the neck.
• thymus - enables the body to produce certain antibodies. It is in front of the heart
• Adrenal is on top of the kidneys. It prepares the body for action, controls the heart rate and breathing in times of emergency
• Pancreas is in between the kidneys. It regulates blood sugar levels
• Testes - control maturation and male characteristics. In the lower abdomen​.
• Ovaries - Influence female traits, and support reproductive function. In the lower abdomen
• Pituitary - Oxytocin, Vasopressin, Growth Hormone
• Thyroid - Thyroxin, Calcitonin
• Parathyroid - Parathyromone
• Thymus - Thymosin
• Adrenal - Adrenaline