Functional Anatomy of the Central Nervous System Chapter 6: The Nervous System Lesson 6.3 Functional Anatomy of the Central Nervous System

Intro to CNS What are the parts of the CNS? Brain Spinal Cord What parts of the brain can you identify? Random Facts Adult human brain weights between 2 ¼ and 3 ¼ lbs. Contains approx 100 billion neurons

The Brain cerebrum diencephalon brain stem cerebellum meninges blood-brain barrier

Cerebrum L and R cerebral hemispheres Makes up the largest portion of the brain

Cerebrum cerebral cortex – outer surface of cerebrum Gyrus – curved raised areas Sulcus – grooves between the gyrus Fissure – deep grooves in the brain Lobes – divided into 4 regions by the sulci Frontal – most anterior – separated by central sulcus Parietal – posterior to frontal lobes – contains primary somatic sensory cortex Occipital – posterior to parietal lobes – responsible for vision Temporal – most inferior lobes – involved in speech, hearing, vision, memory, and emotion

Cerebrum

Cerebrum

Cerebrum primary motor cortex primary somatic sensory cortex In front of central sulcus (frontal lobe) Sends neural impulses to skeletal muscles to initiate and control the development of muscle tension and movement of body parts primary somatic sensory cortex Behind central sulcus (parietal lobe) Interprets sensory impulses received from the skin, internal organs, muscles, and joints

Diencephalon Also known as the interbrain Located deep inside the brain enclosed by the cerebral hemispheres It includes Thalamus – relay station for communicating both sensory and motor information between body and cerebral cortex – regulates sleep, wakefulness, and high alert consciousness Hypothalamus – size of a pearl, regulates heart rate, blood pressure, thirst, hunger, energy, body temp, sex, pain, pleasure Epithalamus – includes pineal gland and regulates sleep-cycle hormones

Diencephalon

Brain Stem Approx size of thumb Includes 3 structures Midbrain – superior end of brain stem, relaty station for sensory and motor impulses, vision, hearing, motor activity, sleep and wake cycles, temp regulation Pons – located below midbrain – regulates breathing medulla oblongata – below pons – regulates heart rate, blood pressure, breathing, and controls reflexes for coughing, sneezing, and vomitting Those with severe brain injuries can continue to live as long as the brain stem remains functional and they stay hydrated and receive nutrition

Cerebrum

Cerebellum Looks like Cerebrum with its outer cortex, convolutions, and dual hemispheres Coordinates body movements including balance

Meninges Protective membranes that surround the brain and spinal cord. Three kinds Dura mater – means hard mother – outer membrane – tough double layered membrane that lies beneath the skull Arachnoid mater – middle membrane – weblike tissue Pia mater – means gentle mother - innermost layer – attaches directly to surface of brain and spinal cord

The Brain

Spinal Cord

Review and Assessment True or False? 1. The gyri divide the brain into 4 regions. 2. The hypothalamus regulates blood pressure. 3. The meninges has 3 layers. 4. The cerebellum coordinates balance. 5. The pons is also called the interbrain.

Functional Anatomy of the Peripheral Nervous System Chapter 6: The Nervous System Lesson 6.4 Functional Anatomy of the Peripheral Nervous System

Functional Anatomy of the Peripheral Nervous System nerve structure cranial nerves spinal nerves and nerve plexuses autonomic nervous system

Nerve Structure endoneurium perineurium epineurium covers axons bundles fascicles epineurium wraps nerves

12 Cranial Nerves

Spinal Nerves and Nerve Plexuses 31 pairs – branch out from L and R side of spinal cord dorsal root ventral root dorsal ramus ventral ramus Plexuses – nerves of neck, arms, legs

Autonomic Nervous System preganglionic and postganglionic neurons – two nerves that connect the CNS to the organs sympathetic nerves Activate fight-or-flight response Releasing adrenaline parasympathetic nerves Controls day in and day out functions resp and dig system resting or digesting system

Injuries and Disorders of the Nervous System Chapter 6: The Nervous System Lesson 6.5 Injuries and Disorders of the Nervous System

Injuries to the Brain and Spinal Cord traumatic brain injury cerebral palsy spinal cord injury

Traumatic Brain Injury violent impact to head mild moderate severe

Cerebral Palsy damage to brain motor function impairment before birth during birth during infancy motor function impairment

Spinal Cord Injuries C1–C3: usually fatal C1–C4: quadriplegia C5–C7: paralysis of lower extremities T1–L5: paraplegia Corepics/Shutterstock.com

Common Diseases and Disorders of the CNS meningitis multiple sclerosis epilepsy Parkinson’s disease dementia and Alzheimer’s disease

Review and Assessment Match these words with 1–4 below: quadriplegia, multiple sclerosis, dementia, cerebral palsy. 1. inflammation destroys myelin sheath 2. loss of memory and thinking 3. loss of function below the neck 4. may begin before birth