What is the role of the brain in the Nervous System?
The brain tells the body how to react, like a central computer.
What are the function of the meninges?
Cover and protect the CNS, protect blood vessels and contain cerebrospinal fluid.
What are the 3 meninges?
Dura Mater (most superficial), Arachnoid Mater and Pia Mater
Describe the Dura Mater?
Tough and leathery. The most superficial meninge.
Describe the Arachnoid Mater?
Middle meninge made of loose spider web of CT. Beneath it is the subarachnoid space filled with blood vessels and cerebral spinal fluid.
Describe the Pia Mater?
Deepest and most delicate meninge. Covers the brain tissue, follows its every ridge and groove.
What is found in the space between the two layers of dura mater?
Where is Cerebrospinal Fluid made?
What are the functions of Cerebrospinal Fluid?
Shock absorption, support and nourishment
What is anatomical position for the spinal cord?
Dorsal at the top, ventral at the bottom. Like someone is laying face down.
What are the posterior projections of the spinal cord and what lives there?
What are the anterior projections of the spinal cord and what lives there?
Ventral Horns/motor neurons
In what sections of the spinal cord are lateral horns located and what lives there?
Thoracic and Lumbar Cords/sympathetic motor neurons, serving visceral organs
What is gray matter made of?
What dictates how much gray matter is at a given level of the spinal cord?
Its proportional to the amount of skeletal muscle innervated.
What is the Dorsal Root Ganglion and what lives there?
An enlargment in the spinal cord that holds cell bodies made of afferent sensory fibers carrying info from peripheral receptors.
What fuses to form the spinal nerves?
The dorsal root (sensory) and ventral roots (motor)
What is white matter made of?
What is the function of white matter?
Allows for communication between the brain and spinal cord or between different regions of the spinal cord.
What is the spinal cords function?
Transmits messages to and from the brain (white matter) and to serve as a reflex center (gray matter)
What is a reflex?
a rapid, predictable, involuntary motor response to a stimulus. May be learned like Pavlov's dog salivating at from ringing of bell
What are the components of a reflex?
Receptor (site of stimulus), Sensory neuron (transmits afferent info to CNS), Integration center (1 or more interneurons), Motor neuron (transmits efferent signals to effector), Effector (muscle or gland)
What are clusters of neuron cell bodies in the CNS called?
What are bundles of nerve fibers (axons) in the CNS called?
What are the regions of the brain?
Cerebrum, diencephalon, brainstem and cerebellum
What is the Cerebrum?
The largest part of the brain. Two hemispheres connected by the corpus collosum. Outer cortex of gray matter surrounding interior that is mostly white matter.
What are gyri?
The ridges of the surface of the brain
What are sulci?
The grooves of the surface of the brain
What are fissures?
Deeper grooves that separate large regions of the brain
What is the Median Longitudinal fissure?
Separates the cerebral hemispheres
What is the Transverse Fissure?
Separates the cerebral hemispheres from the cerebellum below
What are the five lobes of the brain?
Frontal, patietal, temporal, occipital and insula
What is the Central Sulcus?
Separates the frontal lobe from the parietal lobe. Bordering the central sulcus is the precentral gyrus and postcentral gyrus
What is the Precentral Gyrus and its function?
Found anterior to the central sulcus, motor area
What is the Postcentral Gyrus and its function?
Found posterior to the central sulcus, sensory area
What is the Cerebral Cortex?
Made of gray matter and is 40% of brain mass. Allows for sensation, voluntary movement, self-awareness, communication, recognition, and more.
What are the three types of funtional areas of the Cerbral Cortex?
Motor (control voluntary motor functions), Sensory (allow for consious recognitioin of stimuli) and Association (integration)
What is the Primary (Somatic) Motor Cortex?
Located in the precentral gyrus of the frontal lobe. Allows for voluntary motor control. Neurons controlling movement of different body regions do not intermingle
What is the Premotor Cortex?
Involved in learned or patterned skills and planning movements.
What is the Broca's Area?
Directs muscles of tongue, lips and throat that are used in speech production. Involved in planning speech production NOT the motor control of speech
What is the Frontal Eye Field?
Controls voluntary eye movements
What is the Primary Somatosensory Cortex?
Found in postcentral gyrus of the Parietal Lobe. Neurons receive info from sensory neurons in the skin and from proprioceptors which monitor joint position. Contralateral (oposite side) input.
What is the Primary Visual Cortex?
Found in the posterior and medial occipital lobe. Largest of the sensory cortices. Contralateral (opposite side) input.
What is the Auditory Cortex?
Found in the the temporal lobe. Sound waves excite the cochlear receptors which send info to the auditory cortex.
What is the Olfactory Cortex?
Found in the temporal lobe. Receptors in olfactory epithelium are excited by the binding of oderants. They then send their info to the olfactory cortex. Involved in memory of emotion
What is the function of the Insular Lobe?
Emotional response to sensory information
What is the Diencephalon?
Forms the central core of the forebrain. Made up of the Thalamus, Hypothalamus and Pituitary Gland
What is the Thalamus?
80% of the diencephalon. Sensory relay station where sensory signals can be edited, sorted and routed. It decided what info the brain gets to see.
What is the Hypothalamus?
Found in diencephalon. Autonomic regulatory center (BP, HR, resp rate), Emotional Response (fear, pleasure, hunger..) Regulation of body temp, food intake, water balance and thirst, sleep/wake cycles, Hormonal Control
What is the Pituitary Gland?
Found in the diencephalon. The master gland, acts on other glands
What is the Limbic System?
Center of emotion, includes multiple nuclei and tracts.
What is the Cerebellum?
Second largest region of the brain. The "little brain". Two primary functions are adjusting postural muscles and fine-tuning movements controlled at the subconscious and consious levels.
What are the effects of damage to the Cerebellum?
Ataxia (disturbance in balance)
What is the Brain Stem?
It is the instinctive brain, produces automatic behaviors necessary for survival. Located between the cerebrum and the spinal cord. Consists of the midbrain, pons and medulla oblongata.
What are the functions of the Midbrain?
1&2. reflex movement of eyes, head and neck from visual and auditory stimuli, 3. Subconscious control of muscle tone and posture, 4. Substantia nigra: secretes dopamine to inhibit the excitatory neurons of basal nuclei
What is the function of the Pons?
Maintains respiratory rhythm. Sensory and motor nuclei for 4 cranial nerves.
What is the Medulla Oblongata?
Becomes the spinal cord at the level of the forament magnum (hole at base of skull).
What is the function of the Medulla Oblongata?
Associated with cardiovascular centers, respiratory rhythm and motor nuclei of 5 cranial nerves.
What makes up the Peripheral Nervous System?
Made up of 31 spinal nerves and 12 cranial nerves.
What are the two divisions of the Autonomic Nervous System?
Sympathetic and Parasympathetic
What is the Sympathetic Nervous System?
"Fight or flight"; "E" division: Exercise, excitement, emergency and embarrasement.
What is the Parasympathetic Nervous System?
"Rest and digest"; "D" division: Digestion, defecation and diuresis (making urine).
What is antagonistic control?
EX: when one muscle counteracts the action of another muscle.
What is the Autonomic Nervous System structure?
Always consist of two neurons. The first neuron is the preganglionic neuron (myelinated and projects to the autonomic ganglion which contain neuron cell bodies) while the second neuron is the postganglionic neuron (unmyelinated and projects to the effector usually a muscle or gland)
What controls the Autonomic Nervous System?
The hypothalamus is the "boss" and controls responses to stimuli