Exam 5 Anatomy and physiology

What is the function of the basal ganglia?

-Motor Function ( movement ) - The basal ganglia play a role in cognition and emotion. -Filter out incorrect and inappropriate responses only passing the best to the cortex -Inhibit antagonistic or unnecessary movements -Disorders of the basal ganglia include Huntington's disease and Parkinson's disease.

What is the function and location of the major areas of the cerebral cortex?

Cerebral cortex: The cerebral cortex enables us to be aware of ourselves and our sensations, to communicate, remember, understand, and initiate involuntary movements

Classifications by location?

Exteroceptors: are sensitive to stimuli arising outside of the body, most are near or at the body surface Interoceptors: Respond to stimuli within the body, such as from the internal viscera and blood vessels, they monitor a variety of stimuli Propioceptors: Respond to internal stimuli. however their location is much more restricted. Occur in skeletal muscles, tendons, joints and ligaments and in connective tissue coverings of bones and muscles

Signs, symptoms and causes of Huntington's disease?

- A fatal hereditary disorder, strikes during middle age. Mutant huntingtin protein accumulates in brain cells and the tissue dies, leading to massive degeneration of the basal nuclei and later of the cerebral cortex. - Initial symptoms in many are wild, jerky, almost continuous "flapping" movements called chorea. - Although the movements appear voluntary they are not -Huntington's disease is progressive and usually fatal within 15 years.

Describe/Define Cerebrospinal fluid?

- Is found around the brain and spinal cord. - CSF forms a liquid cushion that gives buoyancy to CNS structures - CSF protects the brain and spinal cord from blows and other trauma - CSF is watery similar in composition to blood plasma. - Contains less protein than plasma and its ion concentrations are different - CSF contains more sodium, chlorine, and hydrogen; and contains less calcium and potassium than blood plasma.

Define/Describe Arachnoid mater?

- The middle meningeal layer forms a loose brain covering, never dipping into the sulci at the cerebral surface. - It is separated from the dura mater by a narrow serous cavity the subdural space. - Knoblike projections of the arachnoid mater called arachnoid granulations protrude superiorly through the dura mater.

Define/Describe Pia mater?

- is composed of delicate connective tissue and richly invested with tiny blood vessels - only meningeal layer that clings tightly to the brain like plastic - Small arteries entering the brain tissue carry ragged sheaths of pia mater inward with them for short distances

Define/Describe Dura mater?

- is the strongest and outermost meningeal layer - surrounds the brain, is two layered sheet of fibrous connective tissue. -Attaches to the inner surface of the skull - There is no dural periosteal layer that surrounds the spinal cord.

Descending Pathways and Tracts

-Deliver efferent impulses from the brain to the spinal cord -Direct (pyramidal) pathways: The direct pathways originate mainly with the pyramidal cells located in the precentral gyri. These neurons send impulses through the brain stem via the large pyramidal tracts -Indirect pathways: The indirect pathways include brain stem motor nuclei and all motor pathways except pyramidal pathways. These pathways were formerly lumped together as the extra pyramidal system.

Ascending pathways to the brain?

-First order neurons: conduct impulses from the cutaneous receptors of the skin and from the brain stem where they then synapse with the cell bodies of the second order neurons. -Second order neurons: in dorsal horn of the spinal cord or in medullary nuclei. Transmit impulses to the thalamus or to the cerebellum where the synapse. -Third order neurons: Relay information to the somatosensory cortex of the cerebellum. * in more detail* - Dorsal column medial lemniscal pathways: Mediate, precise, straight-through transmission of impulses from a single type of sensory receptors that can be localized precisely on the body surface, such as discriminative touch and vibration -Spinothalamic Pathways: Receive input from many different types of sensory receptors and make multiple synapse in the brain stem - Spinocerebellar pathways: Third ascending pathway consist of ventral and dorsal spinocerebellar tracts. They convey information about muscle or tendon stretch to the cerebellum, which uses information to coordinate skeletal muscle activity

Signs, symptoms and causes of Parkinson's disease?

-Parkinson's disease results from a degeneration of the dopamine releasing neurons of the substantia nigra -As those neurons deteriorate, the dopamine deprived basal nuclei they target become overactive -Afflicted individuals have a persistent tremor at rest, a forward bent walking posture and shuffling gate, Stiff facial expressions, and are slow at initiating and executing movement.

Define/Describe the meninges?

-Three connective tissue membranes that lie just external to the CNS organs - Cover and protect the CNS - Protect blood vessels and enclose venous sinuses - Contain cerebrospinal fluid - Form partitions in the skull -Are comprised of Pia mater, Dura mater, and arachnoid mater.

Define/characterize each of the different type of brain waves in an EEG?

1.) Alpha Waves (8-13 Hz): are relatively regular and rhythmic, low amplitude, synchronous waves. " a calm relaxed state of wakefulness 2.) Beta Waves (14-30 Hz): Less regular than alpha and with a higher frequency. Occur when we are mentally alert. "concentrating on some problem or visual stimulus. 3.) Theta Waves (4-7 Hz): More irregular. Common in children, but uncommon in awake adults; may appear when concentrating 4.) Delta Waves (4 Hz or less): Are high-amplitude waves seen during deep sleep and when the reticular activating system is suppressed such as anesthesia. In awake adults they indicate brain damage.

What are the six different parts of the sleep cycle? What happens during each stage?

1.) Awake 2.) REM: Skeletal muscles ( except ocular muscles and diaphragm ) are actively inhibited; most dreaming occurs. 3.) NREM (stage 1): Relaxation begins; EEG shows alpha waves; arousal is easy 4.) NREM (stage 2): Irregular EEG with sleep spindles (short high-amplitude bursts); arousal is more difficult 5.) NREM (stage 3): Sleep deepens; theta and delta waves appear; vital signs decline 6.) NREM (stage 4): EEG is dominated by delta waves; arousal is difficult; bed wetting, night terrors, and sleepwalking may occur

Describe the gross anatomy of the spinal cord?

1.) Cervical spinal nerves - Cervical enlargement 2.) Dura and arachnoid mater ( within the thoracic spinal nerves ) 3.) Lumbar enlargement 4.) Conus medullaris( lumbar spinal nerves ) 5.) Cauda equina ( lumbar spinal nerves ) 6.) Filum terminale ( Sacral spinal nerves 0

What is the function of the hypothalamus ( Master control )

1.) Control the autonomic nervous system influencing blood pressure, rate of the heartbeat, digestive tract motility, eye pupil size. 2.) Initiate physical response to emotions 3.) Regulate body temperature 4.) Regulate food intake 5.) Regulate water balance and thirst 6.) Regulate sleep and wake cycles 7.) Control endocrine system function

What is the purpose of an Electroencephalogram ( EEG )?

An EEG is used for diagnosing epilepsy and sleep disorders, in research on brain function, and to determine brain death.

Describe the microscopic anatomy of the spinal cord?

Cervical spinal cord 1.) foramen magnum 2.) Terminus of medulla oblongata of the brain 3.) Sectioned pedicles of cervical vertebrae 4.) Spinal nerve rootlets 5.) Dorsal medial sulcus of spinal cord Thoracic spinal cord 1.) Spinal cord 2.) Vertebral arch (cut) 3.) Cut edge of dura mater 4.) Dorsal root ganglion 5.) Dorsal median sulcus 6.) Dorsal root Inferior end of spinal cord 1.) Spinal cord 2.) First lumbar vertebral arch 3.) Conus medullaris 4.) Cauda Equina 5.) Filum Terminale

What is the difference between declarative vs. procedural memory?

Declarative memory ( facts ): Names, Faces, Words, and Dates; Declarative memory is distinguished by short-term and long-term memory. Procedural memory ( skills ): Memory (piano playing), Motor memory (riding a bike), and emotional memory(your pounding heart when you hear a rattlesnake nearby.

What is the difference between long term-memory vs. Short-term memory

Short term memory: called working memory, is the preliminary step as well as the power that lets you look up a telephone number, dial it then never think of it again. STEM is limited to seven or eight chunks of information. Long term memory: Has limitless capacity.

Signs, symptoms and causes of Cerebrovascular accidents (CVA's or strokes)

Signs/Symptoms: Include blood clots that blocks a cerebral artery Causes: Occur when blood circulation to a brain area is blocked and brain tissue dies of ischemia( a reduction of blood supply that impairs the delivery of oxygen and nutrients

Signs, symptoms and causes of Alzheimer's disease (leading to dementia)

Signs/symptoms: Memory loss, shortened attention spans, disorientation and eventually language loss Causes:

Signs, symptoms and causes of cerebral edema?

Signs/symptoms: Swelling of the brain Causes: - Cerebral edema aggravates the injury - At worst cerebral edema can be fatal

Signs, symptoms and causes of transient ischemic attacks?

Signs/symptoms: Temporary numbness, paralysis, or impaired speech. -Last anywhere between 5-50 minutes -TIA's constitute red flags that warn of impending, more serious CVA's

Signs, Symptoms and causes of a concussion?

Symptoms: Dizziness or loss of consciousness Signs: Dizziness or loss of consciousness Causes: Blow to the head, permanent brain damage( serious concussions known as contusions)

Describe/Define a blood brain barrier?

is the protective mechanism that helps maintain the brains stable environment -Bloodborne substances in the brains capillaries must past through three layers before reaching neurons 1.) The endothelium of the capillary wall 2.) A relatively thick basal lamina surrounding the external face of each capillary 3.) The bulbous of the astrocytes clinging to the capillaries. - The barrier is ineffective against fats, fatty acid, oxygen, carbon dioxide, and other fat soluble molecules that diffuse easily through all plasma membranes - in some brain areas surrounding the third a fourth ventricles, the barrier is entirely absent and the capillary endothelium is quite permeable allowing

Define Lateralization?

Localization of a function or activity on one side of brain or body

What is the function and location of reticular formation

Location of reticular formation: The reticular formation extends through the central core of the medulla oblongata, pons and the midbrain Function of the reticular formation: The reticular formation: - Maintains cerebral cortical alertness - Filters out receptive stimuli - Helps regulate skeletal and visceral muscle activity

What is the function and location of limbic system?

Location of the limbic system: Group of structures located on the medial aspect of the cerebral hemisphere and diencephalon. - The limbic system includes the amygdaloid body: Almond shaped nucleus that sits on the tail of the caudate nucleus. -The main structures of the limbic system include the hypothalamus and the anterior thalamic nuclei -Function: The limbic system is our emotional or affective ( feelings ), brain. - The amygdaloid body is critical for responding to perceived threats ( angry facial expressions ). - The cingulate gyrus plays a role in expressing our emotions through gestures, and resolving mental conflicts when we are frustrated.

General classifications by stimulus type?

Mechanoreceptors: respond to mechanical force such as touch, pressure, vibration and stretch Thermoreceptors: Respond to temperature change Photoreceptors: Such as those of the retina of the eye that respond to light Chemoreceptors: Respond to chemicals in solution( molecules smelled or tasted, or changes in blood or interstitial fluid) Nociceptors: Respond to potentially damaging stimuli that results in pain ex: searing heat, extreme cold, excessive pressure

What is the Motor Area of the cerebral cortex?

Motor Area: Controls voluntary movement, lies in the posterior part of the frontal lobes. Primary Motor Cortex: is located in the precentral gyrus of the frontal lobe of each hemisphere. Large neurons called pyramidal cells allow us to consciously control the precise or skilled voluntary movements of our skeletal muscles Premotor Cortex: Anterior of the precentral gyrus in the frontal lobe. The premotor cortex helps us plan movements; ex. Typing, playing a musical instrument. Broca's Area: Anterior to the inferior region of the premotor area. ( present in the left hemisphere only ) it is the area that directs the muscles involved in speech production Frontal eye field: is located partially in and anterior to the premotor cortex and superior to the broca's area. This cortical region controls voluntary movement of the eyes.

What is the Multimodal Association Areas?

Multimodal Association Areas: Where sensations, thoughts and emotions become conscious. Combine sensory information to memories, decision-making centers 1.) Anterior Association Areas: In the frontal lobe (prefrontal cortex) it is involved with intellect, complex learning abilities, recall, and personality, it contains working memory. 2.) Posterior Association Areas: Is a large region encompassing parts of the temporal, parietal, and occipital lobes. Responsible for recognizing patterns and faces, localizing us and our surroundings in a space. 3.) Limbic Association Areas: Includes the cingulate gyrus, Para hippocampal gyrus and hippocampus. Provides emotional impact that makes a scene important to us.

Classification by receptor structure

General senses: include nonencapsulated( free nerve endings) and encapsulated nerve endings. Nonencapsulated nerve endings: Present nearly every where in the body. Abundant in epithelia and connective tissues. Most of these sensory fibers are nonmyelinated. - Respond to temperature and painful stimuli, but some respond to tissue movements caused by pressure as well

What is the Sensory Area of the cerebral cortex?

Sensory Areas: Areas concerned with conscious awareness of sensation, the sensory cortex, occur in the parietal, insular, temporal and occipital lobes. 1.) Primary Somatosensory Cortex: Resides in the post central gyrus of the parietal lobe, just posterior to the primary motor cortex. Neurons in this gyrus receive information from the somatic sensory receptors in the skin and from position sense receptors in skeletal muscles, joints, and tendons. 2.) Somatosensory Association cortex: Posterior to the primary somatosensory cortex. Integrates sensory inputs ( temp. pressure ) relayed to it via the primary somatosensory cortex to produce an understanding of an object being felt: including size, texture. 3.) Visual Areas: Receive sensory visual inputs. Includes the Primary visual cortex: Seen on the extreme posterior tip of the occipital lobe. Sensation from the eyes which are the largest sensory areas of the brain. Visual association area: How we recognize patterns as images "seeing" 4.) Auditory Areas: On the superior area of the temporal lobe. Includes the primary auditory cortex: receives information from the inner ear. Auditory association area : this is how we hear. 5.) Olfactory Cortex (smell) : On the medial aspect of the temporal lobe in a small region called the periform lobe. Includes the rhinencephalon: Primitive part of the cerebrum containing olfactory centers and the limbic system. 6.) Gustatory Cortex (taste) : A region involved in perceiving taste stimuli. Located in the insula which is deep to the temporal lobe. 7.) Visceral Sensory Area: The cortex of the insula posterior to the gustatory cortex. Involved in the perception of visceral temptations; upset stomach, full bladder, and the feelings that your lungs will burst if you hold your breath for too long

The Brainstem Structures and Functions?

The brainstem regions are the midbrain, pons, and medulla oblongata. Midbrain: Is located between the diencephalon and pons Medulla Oblongata: Lies in the most inferior part of the brain stem. - The medulla oblongata responsibilities. 1.) Adjusts the force and rate of heart contraction to meet the body's needs and the vasomoter center which changes blood vessel diameter to regulate blood pressure 2.) Generate the respiratory rhythm and control the rate and depth of breathing 3.) Regulate activites such as vomitting, hiccuping, swallowing, coughing, and sneezing Pons: Is wedged between the midbrain and the medulla oblongata. Providing linkage between upper and lower levels of the central nervous.

What is the function of the cerebellum?

The cerebellum is located dorsal to the pons and the medulla ( the intervening fourth ventricle ). Protruding under the occipital lobe - Brain region near the nucleus most involved in producing smooth, coordinated skeletal muscle activity.

What is the function of the thalamus?

The relay station for information coming into the cerebral cortex. The thalamus consists of bilateral egg-shaped nuclei, which form the superolateral walls of the third ventricle