Biology - Chapter 8.3: The Central Nervous System (CNS)

spinal cord

- where sensory and motor neurons are found

- vital communication link between the brain and PNS

- spinal cord tissue is protected by cerebrospinal fluid, soft layer tissues, and the spinal column (vertebrae)

white matter

- myelinated neurons

- form the inner regions of some areas of the brain and the outer area of the spinal cord

grey matter

- unmyelinated neurons

- found around the outer regions of the brain and forms the "H-shaped" core of the spinal cord

the brain

- protected by the skull and the meninges

- divided into 3 general regions: hindbrain, midbrain, forebrain

meninges

dura mater, arachnoid later, and pia mater

hindbrain

- coordination and homeostasis

- cerebellum (little brain): involved in unconscious coordination of posture, reflexes, body movement, and fine voluntary motor skills

- medulla oblongata: base of the brain stem coordinates automatic bodily functions that maintain homeostasis (heart rate, breathing, coughing)

- pons

midbrain

- processing sensory input

- process information from sensory neurons in the eyes, ears, and nose

- controls skeletal muscle movement

forebrain

- thought, learning, and emotion

- cerebrum

- thalamus: connects the forebrain and hindbrain

- hypothalamus: regulates the body's internal environment (e.g behaviour, blood pressure, heart rate, body temperature, hunger, thirst). acts as a major link between the nervous and endocrine systems. controls the pituitary gland

- pituitary gland: secretes a large amount of hormones

- cerebrum: divided into right and left cerebral hemispheres; each centres for intellect, learning, memory, consciousness, and language

the blood-brain barrier

- formed by glial cells and blood vessels

- separates blood from the CNS and selectively controls the entrance of substances into the brain from the blood

cerebrospinal fluid

- a dense, clear liquid derived from blood plasma

- transports hormones, white blood cells,and nutrients across the blood-brain barrier to the cells of the brain

- shock absorber: circulates between 2 layers of the meninges (arachnoid and pia mater)

structure and function of the cerebrum

- each half of the cerebrum consists of an internal mass of white matter and a thing, outer covering of grey matter called the cerebral cortex

- corpus callosum: links cerebral hemispheres and sends messages

cerebrum

- cognitive functions originate from both hemispheres (right and left brain)

the cerebral cortex

- 4 lobes

- occipital lobes

- temporal lobes

- parietal lobes

- frontal lobes

occipital lobe

receive and analyze visual information

temporal lobe

share mainly auditory information and some visual processes

parietal lobe

receive/process sensory information from the skin

frontal lobes

- integrate information and controls critical thinking, memory, personality, and fine motor skills

- each side of the frontal lobes control muscles on the opposite end of the body