Anatomy Week 2 Flashcards
What do each of the two anatomical divisions of the nervous system consist of?
- CNS = Brain and Spinal Cord
- PNS:
- Cranial/Spinal Nerves
- Ganglia
- Autonomics
- Enteric Plexuses
- Sensory Receptors
Describe the 3 functional levels of Central Nervous System Organization:
- Sensory (Input) = Afferent neurons
- Integrative (Control) = Interneurons
- Motor (Output) = Efferent neurons
Describe the 3 functional levels of Peripheral Nervous System Organization:
- Somatic Nervous System
- Autonomic Nervous System
- Enteric Nervous System
Motor neurons of the SNS are _______ while motor neurons of the ANS are ______.
- Voluntary
2. Involuntary
Sensory neurons of the SNS receive input from _______, while sensory neurons of the ANS receive input from _______.
- Outside the Body
2. The Viscera (Internal Organs)
What are the 2 divisions of the ANS?
- Sympathetic: Fight or Flight
2. Parasympathetic: Rest and Digest
The basic structural unit of the Nervous System is the _______.
Neuron
Describe the 2 main components of a neuron:
- Cell Body:
- Nucleus
- Nissl Bodies: Clusters of rER - Nerve Fibers:
- Dendrites: Input portion
- Axons: Output portion
What cells are responsible for myelination in the Somatic and Peripheral Nervous Systems respectively?
- Oligodendrocytes
2. Schwann Cells
Describe the 3 different structural types of neurons:
- Multipolar Neurons: Multiple dendrites receiving input, one axon providing output
- Unipolar Neurons: One dendrite and one axon (sensory and often somatic in nature)
- Bipolar Neurons: One dendrite and one axon (associated with special senses)
Differentiate between Ganglia and Nuclei:
- BOTH are collection of neuronal cell bodies.
2. Ganglia are located in the PNS while Nuclei are located in the CNS.
Differentiate between Nerves and Tracts:
- BOTH are bundles of neuronal axons.
2. Nerves are located in the PNS while Tracts are located in the CNS.
Differentiate between White Matter and Grey Matter:
White Matter is primarily composed of white, myelinated axons, while Grey Matter is primarily composed of neuronal cell bodies, dendrites, and un-myelinated axons.
Where are white matter and grey matter located, relative to one another, in the brain and spinal cord respectively?
- In the Brain:
- White Matter INSIDE
- Grey Matter OUTSIDE - In the Spinal Cord:
- White Matter OUTSIDE
- Grey Matter INSIDE (butterfly shape)
Describe the protective coverings of the spinal cord:
- The Meninges: (3 layers)
- Dura Mater (Outer layer)
- Arachnoid Mater (Middle layer)
- Pia Mater (Inner layer)
What is the Epidural Space? What is the SubDural Space?
- The space between the Dura Mater of the spinal cord and the wall of the vertebral canal.
- The space between the Dura Mater and the Arachnoid Mater.
The spinal cord meninges are continuous with _____________.
The meninges of the brain
Describe the Subarachnoid Space? What is special about it?
- The space between the Arachnoid Mater and the Pia Mater.
2. It is filled with cerebrospinal fluid (CSF).
CSF acts as a ______ for the spinal cord.
Shock absorber
The spinal cord extends from the _______ to the ______. It gives rise to _____ pairs of spinal nerves.
- Foramen Magnum of the skull
- L-2 vertebrae
- 31
What are MIXED nerves?
Nerves that have both motor and sensory components
The spinal cord is not uniform in diameter. It has an enlarged _____ region which supplies _______, and it has an enlarged _____ region which supplies _______.
- Cervical
- Upper limbs
- Lumbar
- Lower limbs
The inferior end of the spinal cord proper is called the _______, while the origin of the spinal nerves that EXIT from that inferior end is called the _______.
- Conus Medullaris (at L-1 or L-2)
2. Cauda Equina
What is the filum terminale?
The connective tissue that extends from the conus medullaris to the coccyx
The anterior horn of the grey matter in the spinal cord is called the _______, and the posterior horn is called the ______. In the middle of this butterfly-shaped grey matter is the _______.
- Ventral Horn
- Dorsal Horn
- Central Canal
The short, shallow groove on the posterior side of the spinal cord is called the ______.
Posterior Sulcus
The ventral horn contains ________.
Cell bodies of somatic motor neurons
The dorsal horn contains ________.
Axon terminals of sensory neurons that are delivering signals to motor neuron cell bodies in the ventral horn.
Where do sensory neuron cell bodies originate?
The dorsal root ganglion (a collection of sensory neuron cell bodies in the dorsal root, outside of the dorsal horn).
Many ________ come together to form both dorsal and ventral roots. The ventral root and dorsal root come together to form _________.
- Rootlets (Ventral/Dorsal)
2. Spinal Nerves
Spinal nerves branch into ________, in order to _______.
- Rami (plural of Ramus)
2. Have a dorsal ramus supply the posterior of the body and a ventral ramus supply the anterior of the body.
Where are the cell bodies of AUTONOMIC motor neurons found relative to the spinal cord?
In the Lateral Horn of the grey matter (exitting ventrally like the somatic motor neurons)
Where do autonomic motor neuron axons travel to after entering the spinal nerve?
They follow the ventral ramus to the sympathetic chain to interact with sympathetic ganglions.
Besides somatic sensory neuron cell bodies, what else is found in the dorsal root ganglia?
AUTONOMIC sensory neuron cell bodies (both of which gather signals from their targets (body wall/limbs OR viscera) and deliver them into the dorsal horn of the spinal cord grey matter.
What is a nerve plexus?
A network of branching nerves
Describe the 2 main types of plexuses:
- Visceral Plexus: Associated with ANS
- Contain Symp./Parasymp. Nerves - Somatic Plexuses: Associated with SNS
- Cervical, Brachial, Lumbar, and Sacral Plexus
Which vertebrae do nerves extend from to form each of the Somatic Plexuses respectively?
Cervical: C1-C4
Brachial: C5-T1
Lumbar: L1-L4
Sacral: L4/5-S4
Describe the breakdown of structure of Somatic Nerve Plexuses:
- Roots at Ventral Rami of spinal nerves
- Trunks (Superior, middle, inferior)
- Divisions (Anterior and Posterior)
- Cords (Lateral, Medial, Posterior)
- Branches (Terminal)
What are dermatomes?
Regions of the skin that are known to be supplied by a single nerve. This means that they can be tested for sensation to see if that single nerve is functioning properly.
Describe Erb-Duchene Palsy: (3)
- Injury to the Upper Trunk of Brachial Plexus
- Affects: Suprascapular, Musculocutaneous, and Axillary
- Arm cannot raise (abduct), loss of flexion and supination of forearm (arm in “waiter’s tip position”)
Effects of Radial Nerve Injury: (2)
- Loss of function to Extensors of Forearm
- Wrist Drop
Effects of Median Nerve Injury/Palsy: (2)
- Loss of function to Flexors of Forearm and Thumb (Thenar) muscles
- Loss of Thumb abduction and opposition (loose fist)
Effects of Ulnar Nerve Injury/Palsy: (3)
- Loss of function to most Intrinsic muscles of hand
- Loss of function to Flexors or Medial Digits
- Clawing of Hand (casting a spell)
Effects of Long Thoracic Nerve Injury: (2)
- Loss of function to Serratus Anterior Muscle
- Winging of Scapula
How many neurons are associated with the Somatic and Autonomic pathways respectively?
Somatic: ONE Neuron pathway.
i.e. Motor neurons from CNS synapse DIRECTLY with their target effector.
Autonomic: TWO Neuron pathway.
i.e. Preganglionic neuron–> ganglion–> Postganglionic neuron–> Effector.
ALL somatic motor neurons release ________.
ACh
What are the effector targets of the somatic and autonomic motor neurons respectively?
Somatic: Skeletal Muscle (Voluntary Control)
Autonomic: Smooth Muscle, Cardiac Muscle, and Glands (Involuntary Control)
In the ANS, ALL preganglionic neurons release ______, while SYMPATHETIC postganglionic neurons release ________, and PARASYMPATHETIC postganglionic neurons release ________.
- ACh = Pre-ganglionic
- NE = Sympathetic
- ACh = Parasympathetic
The Sympathetic NS is described as _______, because all of the PreGanglionic Neuronal cell bodies are located in the __________.
- Thoracolumbar
2. Thoracic and Lumbar Vertebrae of the Spinal Cord (specifically T1-L2)
Sympathetic Preganglionic neurons lead to the ______ and ______ ganglia.
- Trunk
2. Pre-vertebral
How are the White and Gray Rami involved in the Sympathetic Chain?
Sympathetic Preganglionic neurons enter the chain through White Rami, and Sympathetic Postganglionic neurons exit the chain through the Gray Rami.
The Parasympathetic NS is considered _________, because its Preganglionic neuron cell bodies are located in the __________.
- Craniosacral
2. Brainstem and Sacral vertebrae of the spinal cord (specifically S2-S4)
Parasympathetic postganglionic neurons terminate _________, and they do not exhibit ________ because they do not _______.
- ON their effector target tissues
- White/Gray Rami
- Enter the sympathetic chain
Plexuses include both _____ and _____ nerves.
Sympathetic and Parasympathetic
Where is the sympathetic chain located?
On either side of the vertebral column running parallel down it
What runs parallel to the sympathetic chain and brings parasympathetic fibers to the neck, thorax, and abdomen?
The Vagus Nerve
Why is the Vagus nerve’s location so important?
Because it contributes the parasympathetic nerve fibers that help form each of the 8 plexuses.
List the 8 plexuses in descending order:
Cardiac Pulmonary Esophageal Celiac Superior Mesenteric Renal Inferior Mesenteric Hypogastric
In the Sympathetic NS, ALL preganglionic motor neurons are found _______. From which they exit through ______ and travel to ______. There, they will _______, and then _______.
- In the LATERAL horns of T1-L2 vertebrae
- The VENTRAL horn
- The Sympathetic Chain
- Synapse with Symp. Chain Ganglia (or Prevertebral ganglia if lower vertebrae originating)
- Postganglionic Symp motor neurons will synapse with their target tissues.
Splanchnic refers to _____. Preganglionic motor neurons of the splanchnic nerves are different from other sympathetic preganglionic motor neurons in that they _________. Instead, they __________.
- Viscera
- DO NOT synapse at sympathetic trunk ganglia
- Continue through Gray Rami as preganglionic motor neurons and synapse at PreAortic Ganglia (Sup./Inf. Mesenteric Ganglia, Celiac Ganglia, Renal Ganglia)
Parasympathetic preganglionic motor neurons originate in the ________ and the _______.
- Brainstem
2. Sacral Vertebrae
Parasympathetic preganglionic motor neurons originating in the brainstem will run WITH the ______.
Cranial Nerves 3,7,9, and 10
Name the 4 cranial nerves that Parasympathetic preganglionic motor neurons run with and the FIVE Ganglia associated with each one (where these neurons will synapse):
Occulomotor Nerve (3): Ciliary Ganglion Facial Nerve (7): Pterygopalatine and Submandibular Glossopharyngeal (9): Otic Vagus Nerve (10): Ganglia close to target tissues
Parasympathetic preganglionic motor neurons originating in the sacral spinal vertebrae will exit through the ________ and branch off to form _______ and synapse at _______.
- Spinal Nerve Ventral Rami
- Pelvic Splanchnic Nerves
- Ganglia close to the effector organs
In order for a Parasympathetic preganglionic motor neuron to get from its brainstem origin to its ganglion, it must pass through a ________. In the case of the preganglionic neurons running with CN-3, they will synapse at the ________ and their postganglionic motor neurons will target the ________.
- Parasympathetic Root
- Ciliary Ganglion
- Sphincter Pupillae Muscle
In the case of the parasympathetic preganglionic neurons running with CN-7, they will either branch off through the ________, synapse at the ________, and their postganglionic motor neurons will target the ________…. OR they will branch off at the _______, BRANCH AGAIN at the _______, synapse at the ______, and their postganglionic motor neurons will target the _______.
- Greater Petrosal Nerve
- Pterygopalatine Ganglion
- Lacrimal Gland
- Pterygopalatine Ganglion
- Chorda Tympani Nerve
- Lingual Nerve
- Submandibular Ganglion
- Submandibular and Sublingual Glands
- Submandibular Ganglion
- Lingual Nerve
In the case of the parasympathetic preganglionic neurons running with CN-9, they will branch off at the ________, synapse at the ________, THEN their postganglionic neurons will branch at the ______, and their postganglionic motor neurons will target the ________.
- Lesser Petrosal Nerve
- Otic Ganglion
- Auriculotemporal Nerve
- Parotid Gland
- Auriculotemporal Nerve
- Otic Ganglion
In the case of the parasympathetic preganglionic neurons running with CN-10, they will synapse at the ________ and their postganglionic motor neurons will target the ________.
- Ganglia close to their effector organs
2. Variety of viscera in the neck, thorax, and pelvic regions
What does “SLUDD” stand for in the Rest and digest response?
Salivation Lacrimation Urination Defecation Digestion
What are Visceral Afferent Neurons?
The sensory neurons of the ANS.
Visceral Afferent Neurons can travel with both ______ and _____ to get back to the _______.
- Sympathetic Nerves
- Parasympathetic Nerves
- Dorsal Horns of the vertebrae
Name the Sympathetic AND Parasympathetic Nerves involved in the Pulmonary Plexus and what response each causes:
Sympathetic:
–>Origin: Pregang. Motors from T1-T4
–>Cause: Vasoconstriction and Bronchodilation
(Increase BP and Air Intake)
Parasympathetic:
–>Origin: Pregang. Motors from Vagus Nerve
–>Cause:Vasodilation and Bronchoconstriction
What are 2 other NT derivatives of glutamate?
Glutamine and GABA
How is Glutamate converted to Glutamine?
How is the reverse reaction catalyzed?
- Glutamine Synthetase adds free Ammonia (NH3) to Glutamate via ATP hydrolysis to create Glutamine
- Glutaminase acts to release the ammonia group as free ammonia from glutamine to yield glutamate.
How is Glutamate converted to GABA?
Glutamate DeCarboxylase and its CoFactor Pyridoxyl Phosphate (PLP) act together to convert it into GABA
While Glutamate is an _______ neurotransmitter, GABA is an ______ neurotransmitter.
- Excitatory
2. Inhibitory
What does GABA stand for?
Gamma Amino Buteric Acid
GABA is released by _______ neurons, then it acts specifically to ______.
- GABAergic
2. Hyper-polarize the membrane of target cells and REDUCE the possibility of Action Potentials occurring
How is GABA cleared when it has done its job?
GLIAL cells come and pick up the GABA molecules, convert them BACK into Glutamate (Via the GABA Shunt and the TCA Cycle), THEN convert them into Glutamine, and finally deliver that Glutamine back into the GABAergic neurons.
Describe the Steps of the GABA Shunt:
- Transamination of GABA to yield Glutamate
- Amino group given from GABA to Alpha-KG allows it to form Succinate.
- Succinate cycles through TCA to ultimately yield Alpha-KG again for another round of GABA Shunt.
How is Histidine converted to Histamine?
One Step Decarboxylation of Histidine via PLP (Vitamin B6) yields Histamine
What is unique about Histamine’s amino acid structure?
It is the only amino acid with a 5-membered ring that has 2 Nitrogens in it.
Most antihistamines don’t actually ______, but rather they _________.
- Block production of Histamine
2. Inhibit it’s receptor
In a neuron, GABA is formed from Glutamate. What is released?
CO2, since it’s a decarboxylation reaction
How is Tyrosine formed from Phenylalanine?
Hydroxylation of the benzene ring by Phenylalanine Hydroxylase and its Cofactor BH4.
What is released from the conversion of Phenylalanine to Tyrosine? How is this product converted back to its original form?
- BH2
2. BH2-Reductase uses NADPH and H+ to convert it back into BH4
How is NADPH formed for the reduction of BH2 to BH4?
From the Pentose Phosphate Pathway
What is a Catechol?
An aromatic ring with TWO hydroxyl groups on it. Adding an amine makes it a Catecholamine.
What is an SSRI?
Selective Serotonin Re-uptake Inhibitor
With only a few additional conversions, Serotonin can be converted into ______.
Melatonin
BH4 is used in ______ reactions.
Hydroxylation
PLP (Vitamin B6) is used in ________ reactions.
Decarboxylation and Transamination
SAM is used in ________ reactions.
Methylation
How is Thyroid Hormone formed?
Tyrosine residues are bound to Thyroglobulin and Iodine atoms are added to it. Then the resides are clipped off of Thyroglobulin and the thyroid gland releases this hormone into the blood.
How is Nitric Oxide (NO) formed?
Nitric Oxide Synthase releases Citrulline from Argenine to form NO.
Nitric Oxide functions to _________.
Mediate relaxation of smooth muscle
How does Nitric Oxide specifically elicit its effect?
It binds to Guanylyl Cyclase, which catalyzes the conversion of GTP into cGMP. This cGMP relaxes blood vessels and increases blood flow to smooth muscle.
How are the effects of Nitric Oxide stopped when it has done its job?
cGMP molecules are converted into GMP by Phosphodiesterase molecules.
Bone is a type of ______ that is _______.
- Connective tissue
2. Calcified
The pectoral girdle consists of the: ____ and _____
- Clavicle
2. Scapula
There are approximately _____ bones in the human body.
206
The pectoral girdle attaches ______ to _____.
- Bones of the free upper limb
2. The Axial skeleton
The clavicle is attached to the sternum at the _______ and to the _______ at the ______.
- Sternoclavicular Joint
- Scapula
- Acromioclavicular Joint
The ______ is the ONLY bone structure that connects the upper limb to the axial skeleton.
Clavicle
The humerus attaches to the _____ of the scapula at the ________.
- Glenoid Fossa
2. Glenohumeral Joint
The Glenohumeral Joint is a ______ joint.
Ball and socket
The humerus articulates with radius at the _______, and with the ulna at the ______.
- Capitulum
2. Trochlea
The humeroradial/humeroulnar joint is a _______ joint.
Synovial Hinge
Hinge joints allow for movement in _____ directions. Those movements are called _______.
- TWO
2. Flexion and Extension
Pivot joints allow for movement in _____ directions. Those movements are called _______.
- TWO
2. Pronation and Supination
An example of a pivot joint is the _______.
Radial Notch (A notch in the Ulna)
The more lateral of the two forearm bones is the _______.
Radius
The radius and ulna are connected by a fibrous joint called the ________.
Inter-Osseus Membrane
The pointy structures on the distal ends of both the radius and ulna are called _______.
Styloid Processes
Muscles are surrounded by connective tissue called ______ which is continuous with ________.
- Epimysium
2. The muscle’s attachment to bone (tendon).
What do tendons do?
Attach muscle to bone
What do ligaments do?
Attach bone to bone (or cartilage to cartilage)
Muscle FIBERS are surrounded by ______ and they collectively form ______.
- Perimysium
2. Fascicles
The basic functional unit of STRIATED muscle is the ______.
Sarcomere
Adduction is ______.
Movement TOWARD the midline
What are the 4 movements of the scapula?
Abduction
Adduction
Retraction
Protraction
What is the fifth possible type of movement for the humerus that is not possible for the scapula?
Circumduction
What are the 4 Rotator Cuff muscles?
SITS: Subscapularis Supraspinatus Infraspinatus Teres Minor
What are the 4 movements of the forearm?
Flexion
Extension
Pronation
Supination
Retraction is when a bone moves ________, while protraction is when a bone moves _______.
- Posteriorly
2. Anteriorly
What movement do the intrinsic muscles of the hand bring about?
Movement of thumb:
- Flexion/Extension
- Adduction/Abduction
- Opposition
Intrinsic Muscles are muscles that _________.
Begin AND end within the hand
What does the term “hypothenar” refer to?
The little finger, which is MEDIAL in the anatomical position.
Dorsal interossei are referred to as ______, while Palmar interossei are referred to as _____.
- DAB - Dorsal Abductors
2. PAD - Palmar Adductors
