THE BRAIN AND SPINAL CORD

SPINAL CORD

The spinal cord is an elongated cylinder of neuron cell bodies, bundles of axons and other cells, protected by connective tissue and bone. It connects to the brain at the medulla oblongata and runs down the vertebral column, the hollow tunnel enclosed within the vertebrae of the spine.

➡️ Function:The spinal cord is part of the central nervous system and serves as a kind of superhighway. Sensory information and motor commands travel up and down, heading to and from the brain.

  CLINICAL CORRELATION : Arteriovenous malformations, meningitis, multiple sclerosis, neural tube defects, polio and post-polio syndrome, spina bifida, spinal muscular atrophy, Syringomyelia. 

MENINGES 

The meninges are the three layers of connective tissue that surround and protect the brain and spinal cord. These are the dura mater, arachnoid mater, and pia mater.

 ➡️ BRAIN 🧠 

The BRAIN is  the upper, expanded part of the central nervous system contained within the cranium (neurocranium or braincase) is a pinkish, soft, ovoid organ that receives sensory input and integrates information to form perception and thought, control activities such as speech and movement, and maintain homeostasis.

CLINICAL CORRELATION : Alzheimer’s Disease, amyotrophic lateral sclerosis, aphasia, arteriovenous malformation, brain aneurysm, brain cancer, cerebral palsy, Chiari malformation, coma, concussion, Creutzfeldt-Jakob Disease, delirium, dementia, encephalitis, epilepsy, fainting, Huntington’s Disease, hydrocephalus, Lewy body disease, migraine, mild cognitive impairment, neuroblastoma, Parkinson’s Disease, progressive supranuclear palsy, seizures, stroke, Tourette Syndrome, transient ischemic attack, traumatic brain injury. 

➡️ BRAINSTEM 

The brainstem connects the spinal cord to the higher-thinking centers of the brain. It consists of three structures: the medulla oblongata, the pons, and the midbrain. 

Function: Besides relaying sensory and motor signals, the structures of the brain stem direct involuntary functions.

 ➡️ MEDULLA OBLONGATA 

The medulla oblongata is continuous with the spinal cord and connects to the pons above. Both the medulla and the pons are considered part of the hindbrain.

Function: The medulla handles respiration, digestion, and circulation, and reflexes such as swallowing, coughing, and sneezing

➡️ PONS VEROLI

The pons, part of the metencephalon of the hindbrain, bridges the two main function areas of the central nervous system, the “higher” brain centers and the spinal cord.

Function: The pons helps control breathing rhythms

➡️MIDBRAIN (MESENCEPHALON) 

The midbrain, or mesencephalon, connects the pons to the diencephalon and forebrain.

Function: The midbrain contributes to motor control, vision, and hearing, as well as vision- and hearing-related reflexes

 ➡️CEREBELLUM 

The cerebellum is the second largest part of the brain. It sits below the posterior (occipital) lobes of the cerebrum and behind the brain stem, as part of the hindbrain. Like the cerebrum, the cerebellum has left and right hemispheres. A middle region, the vermis, connects them. 

Function: The primary function of the cerebellum is to maintain posture and balance

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➡️CEREBRUM 

The cerebrum is the largest brain structure and part of the forebrain (or prosencephalon). Its prominent outer portion, the cerebral cortex, not only processes sensory and motor information but enables consciousness, our ability to consider ourselves and the outside world. The cortex tissue consists mainly of neuron cell bodies, and its folds and fissures (known as gyri and sulci) give the cerebrum its trademark rumpled surface. The cerebral cortex has a left and a right hemisphere. Each hemisphere can be divided into four lobes: the frontal lobe, temporal lobe, occipital lobe, and parietal lobe

 ➡️CORPUS CALLOSUM 

The corpus callosum, a central white commissure that crosses the midline of the brain, connects corresponding gray matter regions of two hemispheres of the cerebrum, allowing communication between the two sides of the brain and enabling integrated function

➡️FRONTAL LOBE 

The frontal lobe, the most anterior of the cerebrum’s four lobes, extends from the anteriormost region of the cerebrum to the central sulcus.

Function: The speech center, known as Broca’s area, is in the frontal lobe. Other regions of the frontal lobe are involved in what are considered to be “higher functions” such as planning and long-term memory

➡️TEMPORAL LOBE 

The temporal lobe  of the cerebrum contains an auditory cortex that receives input from the cochlear nerve, and association areas that integrate auditory, olfactory, and complex pattern perception

➡️ PARIETAL LOBE 

The parietal lobe  of the cerebrum integrates sensory information and plays a role in spatial perception.

Function: The postcentral gyrus , or primary somatosensory cortex, is located in the parietal lobe. It receives sensory information and gives the perception of touch. Other areas of the parietal lobe process awareness of body’s motion, touch, perception of temperature, pain, and movement

➡️OCCIPITAL LOBE 

The occipital lobe is the posterior lobe of the cerebrum that receives input from the eye and processes visual perceptions