Chpt. 11 - Nervous System II Flashcards
Meninges
- Dura mater, arachnoid mater, pia mater
- protect brain and spinal cord
Dura mater
- outermost layer
- composed of tough, white, dense connective tissue and contains many blood vessels and nerves
- epidural space underneath
Arachnoid mater
-between dura and pia
-thin, weblike membrane w/o blood vessels
(!) -subarachnoid space underneath that contains CSF
Pia mater
- innermost layer
- thin and contains many nerves and blood vessels
Ventricles
- four interconnected cavities that lie in the cerebral hemisphere and brainstem
- filled with CSF
CSF
- cerebral spinal fluid
- nutritive and protective
- secreted by choroid plexuses lined in ventricles
- contains greater concentration of sodium and lesser concentrations of glucose and potassium than other extracellular fluid
Forebrain, Diencephalon, Brainstem, Hindbrain
Forebrain: cerebrum and basal nuclei
Diencephalon: Thalamus, Pineal Gland, Hypothalamus
Brainstem: Midbrain, Pons, Medulla oblongata
Hindbrain: Cerebellum, pons, Medulla oblongata
Cerebrum
- largest part of the brain
- 2 cerebral hemispheres connected via corpus callosum
- Frontal, parietal, temporal, occipital, insula
Cerebral cortex
- provides higher brain functions: interpreting impulses from sense organs, initiating voluntary muscular movements, storing information as memory, and retrieving this information in reasoning
- responsible for intelligence and personality
- thin layer of gray matter that constitutes the outermost portion of the cerebrum
- contains about 75% of all neurons in nervous system
Association areas
- analyze and interpret sensory experiences
- occupy anterior portions of frontal lobe, lateral portions of parietal, temporal, occipital
- provide memory, reasoning, verbalizing, judgement, and emotions
Broca’s area
- motor speech area
- allows for physical speech
- frontal lobe
Wernicke’s area
- sensory speech area
- understanding and formulating written and spoken language
- parietal lobe and temporal lobe
Frontal Lobe Function
- Association: higher intellectual process (problem solving, judgement, concentration)
- Motor: control voluntary skeleton muscles
Parietal Lobe Function
- Sensory: provide sensations (temperature, touch, pressure, pain)
- Association: understanding speech and using words to express thoughts
Temporal Lobe Function
- Sensory: hearing
- Association: interpret sensory experiences, remember visual scenes, music, sensory patterns
Occipital Lobe Function
- Sensory: vision
- Assocation: combine visual images with other sensory experiences
Basal nuclei/ganglia
- gray matter masses deep within cerebral hemispheres
- produce dopamin
Diencephalon
-includes: Thalamus, Pineal Gland, Hypothalamus
Thalamus
-relay station for sensory impulses ascending from spinal cord
Hypothalamus
- Maintain homeostasis
- regulates visceral activities (heart rate, body temp, water, hunger, body weight)
- links nervous and endocrine system
Pineal gland
- produces melatonin and makes you go sleepy sleep
- CONTAINS DMT U GONNA GET SO HIGHHHHH when u smoke this gland homie
Brainstem
- connects the cerebrum to the spinal cord
- includes: Midbrain, Pons, Medulla oblongata
Midbrain
-reflex centers that move the head, maintains posture
Pons
- helps regulate rate and depth of breathing
- relays impulses between medulla oblongata and cerebrum
Medulla oblongata
- cardiac, vasomotor, respiratory control centers
- conducts ascending and descending impulses between brain and spinal cord
Reticular formation
- scattered throughout brainstem in small gray matter isles
- mediates the levels of consciousness/sleep/alertness
Limbic system
-controls emotional experience and expression and modifies the way a person acts
~~FEEEEEELING AND EMOTIIIIONS~~ o-o
Cerebellum
- coordinates muscle activities and maintains posture
- integrates sensory information concerning position of body parts
Spinal cord
- originates: nervous tissues leaving cranial cavity
- ends: intervertebral disc that separates L1 and L2
- consists of 31 segments with spinal pairs
Functions of spinal cord
- Center for spinal reflexes
- conduit for impulses to and from the brain
Reflex
- automatic responses to stimuli inside or outside body
- maintain homeostasis by controlling involuntary processes
- nerve pathway that begins with a sensory receptor and ends with an effector
- includes as few as two neurons
Reflex arc
-includes: (1) sensory neuron (2) integration with CNS (3) motor neuron (4) effector
Patellar reflex
- simple monosynaptic reflex that only involves two neurons: sensory neuron and motor neurons
- when patella is struck, nuscle contracts
Withdrawal reflex
- involes sensory neuron, interneuron, motor neuron
- pulls foot away from painful stimuli
crossed extensor reflex
- muscles on one side contract, while muscles on other side are inhibited
- due to interneuron pathways in spinal cord that pass sensory signals to other side
Ascending tracts
- spinal cord parts that conduct sensory information to the brain
- involve 3 neurons between a sensory receptor and the brain (peripheral sensory neurons and two interneurons)
- fasciculus gracilis/cuneatus
- spinothalamic tracts
- spinocerebellar tracts
Fasciculus gracilis/cuneatus tract
- Ascending tract
- posterior portion of spinal cord
- conduct sensory impulses from skin, muscles, tendons, and joints to brain
- impulses originating from sensory receptors of left side will be read reach right side of brain, vice versa
Spinothalamic tracts
- Ascending tracts
- sensations of pain and temperature
- cross over in the spinal cord
Spinocerebellar tracts
-coordinate muscular movements
Descending tracts
- conduct impulses from the brain to motor neurons reaching muscles and glands
- corticospinal
- reticulospinal
- rubrospinal
Corticospinal tracts
- descending tracts
- conduct motor impulses associated with voluntary movement from brain to skeletal muscles
Reticulospinal tracts
- descending tracts
- conducts motor impulses maintance with muscle tone and activity of sweatglands from brain to effectors
Rubrospinal tracts
- descending tracts
- conduct motor impulses associated with muscular coordination from the brain
Cranial nerves
I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducens VII Facial VIII Vestibulocochlear IX Glossopharyngeal X Vagus XI Accessory XII Hypoglossal
Olfactory
- I, 1st
- Sensory: sense of smell
Optic
- II, 2nd
- Sensory: sense of vision
Oculomotor
- III, 3rd
- sensory: proprioceptors
- motor: move eye stuff
Trochlear
- IV, 4th
- sensory: proprioceptors
- motor: move eye
Trigeminal
- V, 5th
- Opthalmic, Maxillary, Mandibular divisions
- motor: mastication
- sensory: face stuff
Abducens
- VI, 6th
- motor: move the eyes
- sensory: some proprioceptors
Facial
- VII, 7th
- sensory: tongue
- motor: facial expressions, tear glands, salivary glands
Vestibulochochlear
- VIII, 8th
- sensory: equilibrium, hearing
Glossopharyngeal
- IX, 9th
- sensory: bitter taste (posterior tongue), pharynx, tonsils
- motor: swallowing
Vagus
- X, 10th
- sensory: abdomen, esophagus, larynx
- motor: speech and swallowing
Accessory
- XI, 11th
- motor: neck and back, some proprioceptor input
Hypoglossal
- XII, 12th
- motor: move tongue
Autonomic Nervous System
- part of the PNS that functions independently and continuously, w/o conscious effort
- controls visceral activities that aid in maintaining homeostasis
- includes Sympathetic and parasympathetic system
Sympathetic Nervous System
- fight or flight response
- pupil dilation, increased sweating, increased heart rate, increased blood pressure
- noradrenaline and adrenaline bind adrenergic receptors
Parasympathetic Nervous System
- rest and digest system
- conserves energy by slowing heart rate, increasing intestinal and gland activity
Preganglionic fiber
- axon of autonomic neuron
- leaves the CNS and synapses with one or more neurons that are associated with autonomic ganglion
- originate from lateral horn of the spinal cord
Postganglionic fiber
- axon of second neuron
- extends to a visceral effector (like heart, or lungs, or booobies huehuehue)
