(A summary from the above website)
CNS – Central Nervous System – Brain and Spinal Cord
PNS – Peripheral Nervous System – spinal nerves that branch from the spinal cord and cranial nerves that branch from the brain
The brain is an amazing three-pound organ that controls all functions of the body, interprets information from the outside world, and embodies the essence of the mind and soul. Intelligence, creativity, emotion, and memory are a few of the many things governed by the brain. Protected within the skull, the brain is composed of the cerebrum, cerebellum, and brainstem.
The brain receives information through our five senses: sight, smell, touch, taste, and hearing – often many at one time. It assembles the messages in a way that has meaning for us, and can store that information in our memory. The brain controls our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body.
The central nervous system (CNS) is composed of the brain and spinal cord. The peripheral nervous system (PNS) is composed of spinal nerves that branch from the spinal cord and cranial nerves that branch from the brain.
The brain is composed of the cerebrum, cerebellum, and brainstem.
is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement.
is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance.
acts as a relay center connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing.
Right brain – left brain
The cerebrum is divided into two halves: the right and left hemisphere.
Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed.
Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people.
Personality, behavior, emotions
Judgment, planning, problem solving
Speech: speaking and writing (Broca’s area)
Body movement (motor strip)
Intelligence, concentration, self awareness
Interprets language, words
Sense of touch, pain, temperature (sensory strip)
Interprets signals from vision, hearing, motor, sensory and memory
Spatial and visual perception
Interprets vision (color, light, movement)
Understanding language (Wernicke’s area)
Sequencing and organization
The surface of the cerebrum is called the cortex. It has a folded appearance with hills and valleys. The cortex contains 16 billion neurons (the cerebellum has 70 billion = 86 billion total) that are arranged in specific layers. The nerve cell bodies color the cortex grey-brown giving it its name – gray matter
Beneath the cortex are long nerve fibers (axons) that connect brain areas to each other — called white matter.
Hypothalamus: master control of the autonomic system.It plays a role in controlling behaviors such as hunger, thirst, sleep, and sexual response. It also regulates body temperature, blood pressure, emotions, and secretion of hormones.
Pituitary gland: Known as the “master gland,” it controls other endocrine glands in the body.
Pineal gland: Heps regulate the body’s internal clock
Thalamus: relay station – plays a role in pain sensation, attention, alertness and memory
Basal ganglia: coordinate fine motions, such as fingertip movement
Limbic system: center of our emotions, learning, and memory
Memory is a complex process that includes three phases: encoding (deciding what information is important), storing, and recalling. Different areas of the brain are involved in different types of memory (Fig. 6). Your brain has to pay attention and rehearse in order for an event to move from short-term to long-term memory – called encoding.
Short-term memory, also called working memory, occurs in the prefrontal cortex. It stores information for about one minute and its capacity is limited to about 7 items. For example, it enables you to dial a phone number someone just told you. It also intervenes during reading, to memorize the sentence you have just read, so that the next one makes sense.
Long-term memory is processed in the hippocampus of the temporal lobe and is activated when you want to memorize something for a longer time. This memory has unlimited content and duration capacity. It contains personal memories as well as facts and figures.
Skill memory is processed in the cerebellum, which relays information to the basal ganglia. It stores automatic learned memories like tying a shoe, playing an instrument, or riding a bike.
Ventricles and cerebrospinal fluid
The brain has hollow fluid-filled cavities called ventricles. Cerebrospinal fluid (CSF) flows within and around the brain and spinal cord to help cushion it from injury. This circulating fluid is constantly being absorbed and replenished.
The skull is formed from 8 bones that fuse together along suture lines. These bones include the frontal, parietal (2), temporal (2), sphenoid, occipital and ethmoid. The face is formed from 14 paired bones including the maxilla, zygoma, nasal, palatine, lacrimal, inferior nasal conchae, mandible, and vomer———–