Exam 1 Flashcards
What are the 2 major divisions of the nervous system?
-Central Nervous System (CNS)
-Peripheral Nervous System (PNS)
What are the components of the CNS?
-Brain
-Cortex
-Cerebellum
-Brain Stem
-Spinal Cord
What is the function of the CNS?
Information integration
What are the components of the PNS?
-Autonomic Nervous System (ANS)
-Somatic Nervous System
-Cranial Nerves
-Spinal Nerves
What is the primary function of the Somatic Nervous System?
Conscious reactions to external stimuli
-by way of cranial and spinal nerves
What is the primary function of the Autonomic Nervous System?
To maintain homeostasis
-by way of the sympathetic and parasympathetic nervous systems
What is the function of the Sympathetic Nervous system?
-Fight or Flight Response (Freak out response)
-Helps the body effectively respond to stressful circumstances
What is the function of the Parasympathetic Nervous System?
-Rest and digest response (Chill the heck out response)
-Helps the body chill out to function properly under normal circumstances
What are the 2 Cell types in the Nervous System?
-Neuron
-Neuroglia
What is the function of a neuron?
Communication
What is the function of a Neuroglia?
To support neuron function and survival (through diverse methods)
What are the components of a Neuron?
-The Dendrite: receiving pole
-The Cell Body: “command center” of a neuron
-The Axon: transmission of impulses
What is the difference between Unipolar, Bipolar, and Multipolar Neurons?
The number of Dendrites the Neuron has:
-Unipolar: No dendrites (as seen in sensory neurons)
-Bipolar: One dendrite (as seen in olfactory epithelium and the retina)
-Multipolar: Multiple dendrites (most common type of neuron)
What are the Sub-types of Neurons?
-Afferent (Sensory): Sends info from the periphery up to the brain
-Efferent (Motor): Sends info from the brain down to the periphery
-Interneuron: Communication between neurons
What are the types of Neuroglia?
-Oligodendrocytes: precursor to myelin in the CNS
-Schwann Cells: precursor to myelin in the PNS
-Have properties that aid in cell regeneration
-Unless cell body dies
What is Myelin and what is its function?
-It’s a cellular sheath of lipid material wrapped around an axon
-It insulated axons
-It increases conduction velocity of an impulse
-The bigger the bundles of myelin, the faster the impulse
Explain the Basic Neurophysiology Concepts?
- You start with a Resting Membrane Potential
- A stimulus applied to a cell body results in Depolarization
2a. If the only partial Depolarization, this will result in Repolarization (restoration back to Resting Membrane Potential)
2b. If full Depolarization, this will result in stimulus reaching the Threshold - Once Threshold is reached, an Action Potential is created, and an impulse is fired down the axon
What are the types of Summation and what do they mean?
-Spatial Summation: a greater NUMBER of stimuli coming into a cell membrane increases the odds for the formation of an action potential
-Temporal Summation: The TIMING of the stimulation at the receptor site can increase the probability of action potential formation
The Afferent system is made up of 2 types of sensations. What are they called and what is the difference between them?
-Primary Sensation:
-Superficial Sensory Receptors: Touch
-Deep Sensory Receptors/Proprioception: Position sense, Movement sense (kinesthesia), vibration
-Secondary Sensation: Provides meaning to primary sensation
-e.g. stereognosis (the ability to perceive the object you are touching without looking), graphesthesia (the ability to perceive what is being written on your skin without looking), 2-point localization, baresthesia (the ability to distinguish weight without looking)
In other words: Primary sensations are very basic (e.g. touch, pressure, and movement); Secondary sensations take it a step further by providing meaning the primary sensations
Which type of receptors are the Fastest Processing?
Proprioreceptors
Definition: There is an increase in awareness of a sensation when a stimulus is applied (relates to impulse firing) that may “wear off” as that stimulation continues.
Sensory Habituation/Adaptation
What are the 2 types of Efferent System Neurons and what is their function?
-Upper Motor Neurons: Send impulses from the Brain down to the Lower Motor Neurons located in the Spinal Cord
-Lower Motor Neurons: Send impulses from the Spinal Cord to the muscles or glands
What are the Types of Lower Motor Neurons and what are their functions?
-Alpha Motor Neurons: Innervate Extrafusal Muscle Fibers to contract muscle
-Phasic (Fast twitch fibers which are superficial)
-Tonic (Slow twitch fibers which are deep)
-Gamma Motor Neurons: Innervate Intrafusal Muscle Fibers to contract muscle (Stretch Reflex)
What is the Simple Reflex Arc?
Afferent Neuron > Interneuron > Efferent Neuron
Definition: Built-in neural circuits that produce stereotyped movement responses.
Reflex
What is the term used to describe Pre-natal Development?
Ontogenesis
What are the 3 phases of Pre-natal Development and when do they occur?
-Germinal Phase: Conception- 3 wks gestation
-Embryonic Phase: 3 wks gestation- 8 wks gestation
-Fetal Phase: 8 wks gestation- 38/40 wks gestation
What happens in the Germinal Phase of Pre-natal Development?
Rapid cellular division (mitosis) into 3 layers
-Endoderm (inner layer): precursor to internal organs, lining of viscera
-Mesoderm (middle layer): bone, cartilage, blood, muscle, connective tissue
-Ectoderm (outer layer): nervous system, skin
Definition: Development of the neural tube (which is the precursor to the brain and SC)
Neurulation
What happens in the Embryonic Phase of Pre-Natal Development?
Major growth and differentiation of major body systems and organs (cells receive their designations or specific jobs)
-In nervous system, cellular proliferation and migration
What happens in the Fetal Phase of Pre-Natal Development?
Rapid growth and change in body form
Definition: Formation of chemically mediated synapses
Synaptogenesis
When does Synaptogenesis occur?
-After the process of Neurulation
-Approx. 6 wks gestation- well after birth
What is Myelinization and when does it occur?
-The formation of myelin around an axon (for coordination)
-Begins at 20-30 wks gestation and continues to approx. 10 years
In which direction does Myelinization occur?
-Caudal (from the tail) to Rostral (from the nose)
-Distal to Proximal
In which direction do reflexes develop?
Caudal (from the tail) to Cephalic (from the head)
Characteristics of?:
-Present at birth (full term) or early infancy
-Automatic, stereotyped responses to sensory stimuli
-Function to meet survival needs of infant
-Become integrated as more mature movement patterns develop
-Are considered Spinal Level Reflexes
Primitive Reflexes
Which type of Reflex?
-stroke cheek and head turns toward stimulus with mouth open stimulating a suck reflex
Rooting Reflex (Primitive)
When in the Rooting Reflex integrated?
0-3 months
Which type of Reflex?
-Extension of the head produces total body extension, followed by flexion.
Moro Reflex (Primitive)
When is the Moro Reflex Integrated?
-4-6 months
Which type of Reflex?
-Stroke the palm elicits grasp
-Pressure to the sole of the foot elicits flexion of toes
Palmar/Plantar Grasp Reflex (Primitive)
When is the Palmar/Plantar Grasp Reflex Integrated?
About 9 months
Which type of Reflex?
-Stroke the sole of the foot to elicit fanning of the toes
Babinski Reflex (Primitive)
When is the Babinski Reflex Integrated?
Around 9 months
Which type of Reflex?
-Tactile pressure to sole of foot, legs extend to support the body
Positive Support (Primitive)
When is the Positive Support reflex integrated?
2-6 months
Which type of reflex?
-Feet contacting a surface will elicit step-like movements in the legs
Primitive Walking (Primitive)
When is the Primitive Walking reflex integrated?
About 2 months
Which type of Reflex?
-Noxious stimuli to the foot will result in withdrawal from stimulus
-Contralateral limb will extend
Flexor Withdrawal/Crossed Extension (Primitive)
Definition: Group of automatic responses to attain and maintain an upright posture.
Postural Reflexes
Which Neural Level are Tonic Reflexes?
Brainstem
Which type of Reflex?
-Elicited by joint receptors in the neck
-Cervical rotation elicits ipsilateral UE extension, contralateral UE flexion
ATNR
Which type of Reflex?
-Elicited by joint receptors in the neck
-Cervical flexion elicits UE flexion, LE extension
-Cervical extension elicits UE extension, LE flexion
STNR
Which type of Reflex?
-Elicited by utricule stimulation from gravity
-Supine position stimulates extensor tone
-Prone position stimulates flexor tone
Tonic Lab
Which Neural Level are Righting Reactions?
Mid-Brain
Which type of Reflexes help to produce Tone?
Tonic Reflexes
Which type of Reflexes help to regain orientation, alignment of body parts?
Righting Reactions
Which type of Reflex?
-Helps to orient the head in line with gravity
-Elicited through utricle stimulation from gravity
Labyrinthine Righting (LRR)
Which type of Reflex?
-Uses visual input to align head
-Elicited through vision receptors
Optical Righting
Which type of Reflex?
-Assists with realigning head position when the body moves
-Elicited through joint receptors in the neck
Neck Righting
Which type of Reflex?
-As the head moves, the body will re-align itself
-Elicited by joint and touch receptors
Body on Head Righting
Which type of Reflex?
-As the upper or lower body move, the other half of the body will follow
-Elicited by touch receptors
-Related to asymmetrical touch on the body producing rotation
Body on Body Righting
Which type of Reflexes are the most mature postural responses, and develop to the front first, side second, and back last?
Equilibrium and Protective Response
Which Neural Level are Equilibrium and Protective Responses?
Cortical
Which type of Reflex?
-Elicited by rapid displacement of the body
-Response elicited by stimulation to semicircular canals
-Body will protect itself by reaching in the direction of displacement
Protective Response
Which type of Reflex?
-Adaptation of body segments to change of position by realigning body segments over the base of support
-Response elicited by stimulation to semi-circular canals
Equilibrium Response
In which order do the Neural Level of Reflexes develop?
- Spinal Cord
- Brainstem
- Mid-Brain
- Cortical
In which order do Reflex Types develop?
- Primitive
- Tonic
- Righting
- Equilibrium and Protective
In which order do Motor Stages Develop?
- Prone
- Supine
- Quadruped/Sitting
- Standing
- Walking
What structures are included in White Matter?
Myelinated structures (aka: axons, fibers)
What structures are included in Gray Matter?
Cell bodies and Dendrites
What are the 3 types of Fibers (axons) and what do they do?
-Commissural: left to right
-They communicate between hemispheres
-Association: within a specific area
-They associate between different lobes within a hemisphere
-Projectile: ascending/descending
-They are located in the spinal cord
What are Tracts in terms of fibers/axons?
Bundles of axons
What are Meninges?
Membranes surrounding the brain and spinal cord
What are the 3 Meningeal Layers and where are they located?
-Dura Mater: closest to bone
-Arachnoid Mater: middle membrane
-Pia Mater: closest to neural tissue
Where is the Sub-Arachnoid space located?
Between the Arachnoid and Pia Mater