Nervous System

• The functions of the nervous system are sensory input, information processing, motor output, coordinating and controlling the body, integration, homeostasis, and mental activity.
• The brain is divided into two parts: the central nervous system and the peripheral nervous system.
• The central nervous system consists of the brain and spinal cord.
• The peripheral nervous system consists of nerves, ganglia, sensory division (afferent), and motor division (efferent).
• The function of the central nervous system is to control intelligence, emotions, speech, and the ability to feel and move.
• The peripheral nervous system is divided into two parts: the autonomic nervous system, which controls involuntary bodily functions and regulates glands, and the somatic nervous system, which controls muscle movement and relays information from ears, eyes, and skin to the central nervous system.
• The autonomic nervous system is classified into two: the sympathetic nervous system (the "fight or flight") and the parasympathetic nervous system.
• Sympathetic Nervous System: One of the classifications of the autonomic nervous system is the "fight or flight" of the body to either depend on yourself, escape the threat, or carry signals to keep your body alert.
• Parasympathetic Nervous System: One of the classifications of the autonomic nervous system that brings all the systems of the body back to normal or carries signals to keep the body relaxed.
• Neurons, dendrites, and axons are parts of the cell nervous system.
• Neurons receive stimuli and transmit action potentials to other neurons or to effector organs.
• Dendrites receive information from other neurons or from sensory receptors and transmit the information to the neuron cell body.
• Axons are nerve fibers that transmit information to different nerves, muscles, and glands.
• The brain consists of the cerebrum, cerebellum, midbrain, cerebral cortex, pons, medulla oblangata, grey matter, and white matter. 
• Cerebrum: part of the brain that is located at the top and front of the head. It is the largest part of the brain as a whole and consists of two hemispheres, which are the left and right.
• The cerebellum is also called the "little brain." It is located below the cerebrum and above the 1st cervical, located at the back of the head, just above the spinal cord. It is responsible for coordinating voluntary movements and motor skills such as balance, coordination, and posture.
• The midbrain is located below the cerebral cortex, at the topmost part of the brain's stem, and below the cerebrum. It is responsible for the eye and auditory reflexes and involves the movement of the body and head as it provides pathways for downward pathways for the cerebral cortex.
• The cerebral cortex is on top of the white matter pathway. The ridges are called gyri, while the valleys are called sulci.
• Gyri = Ridges

  Sulci = Valley
• Pons is located below the midbrain in the brainstem. It is responsible for unconscious processes and certain reflex actions such as chewing, tasting, and saliva production.
• The medulla oblangata is located at the bottom of the brainstem and connects the spinal cord. It is also known as the "Center for Respiration."
• Medulla oblangata is also known as the "Center for Respiration."
• The cerebellum is also called the "little brain."
• Medulla oblangata is responsible for and controls vital processes such as heart rate, breathing, and blood pressure.
• The medulla oblangata controls cardiac, respiratory, and vasomotor entry.
• Grey matter: closely packed neuron cell bodies (making up the cerebral cortex)
• White matter: neuronal tissue containing mainly long myelinated axons and also known as the diencephalon.
• Four Lobes of the Brain: Frontal Lobe, Parietal Lobe, Occipital Lobe, and Temporal Lobe.
• Frontal Lobe: One of the four lobes that is behind the forehead and has functions that control memories, personality, critical thinking, and reasoning.
• Parietal Lobe: Located underneath the crown of the skull, at the at the top rear of the head, it functions in receiving and processing sensory input such as touch, pressure, heat, cold, and pain.
• Occipital Lobe: It sits back at the back of the head and is the smallest lobe. Its functions are visual, color, form, and motion.
• A visio-spatial deficit is when people have difficulties understanding what they see around them, such as colors, forms, and navigating movements.
• Temporal lobe: close to the base of the skull behind the ears and the 2nd largest lobe. It controls auditory perception.
• Diencephalon is divided into two parts, which are the thalamus and hypothalamus.
• Thalamus plays a role in sleep, wakefulness, consciousness, learning, and memory.
• The hypothalamus controls homeostasis, or stable state, and temperature.
• Cranial nerves for the eyes: optic, oculomotor, trochlear, and abducens.
• Olfactory: sense of smell.
• Optic: sense of sight.
• Oculomotor: extraocular eye movements, pupil contraction, lens shape.