Topic 5 & 6: Muscles (Lab) and Neuronal Communication (Lecture) Flashcards
What is the function of the frontalis muscle?
Raises eyebrows and wrinkles forehead.
What is the function of the orbicularis oculi?
Closes eyelids; used in blinking, squinting, and winking.
What is the function of the zygomaticus major?
Elevates corners of the mouth (smiling).
What is the function of the orbicularis oris?
Closes and protrudes lips; involved in kissing and speech.
What is the function of the temporalis muscle?
Elevates and retracts the mandible (closes jaw).
What is the function of the masseter?
Elevates the mandible (closes jaw).
What is the function of the buccinator muscle?
Compresses cheek; holds food between teeth while chewing.
What is the origin, insertion, and action of the sternocleidomastoid?
Origin: Manubrium of sternum and medial clavicle; Insertion: Mastoid process of temporal bone; Action: Flexes neck, rotates head to opposite side.
What is the origin, insertion, and action of the digastric muscle?
Origin: Anterior belly from mandible, posterior belly from mastoid notch of temporal bone; Insertion: Hyoid bone; Action: Depresses mandible and elevates hyoid during swallowing.
What is the origin, insertion, and action of the sternohyoid muscle?
Origin: Manubrium of sternum and medial clavicle; Insertion: Body of hyoid bone; Action: Depresses hyoid bone after swallowing.
What is the function of the serratus anterior?
Protracts and stabilizes scapula; assists in upward rotation.
What is the function of the external intercostals?
Elevates ribs during inspiration.
What is the function of the internal intercostals?
Depresses ribs during forced expiration.
What is the function of the pectoralis major?
Adducts and medially rotates humerus.
What is the function of the pectoralis minor?
Stabilizes scapula by drawing it inferiorly and anteriorly.
What is the function of the deltoid?
Abducts arm; anterior fibers flex and medially rotate arm; posterior fibers extend and laterally rotate arm.
What is the function of the coracobrachialis?
Flexes and adducts arm at shoulder.
What is the function of the biceps brachii?
Flexes elbow and supinates forearm.
What is the function of the brachialis?
Flexes forearm at elbow.
What is the function of the brachioradialis?
Flexes forearm at elbow, especially during mid-pronation.
What is the function of the pronator teres?
Pronates forearm and assists with elbow flexion.
What is the function of the flexor carpi radialis?
Flexes and abducts hand at wrist.
What is the function of the flexor carpi ulnaris?
Flexes and adducts hand at wrist.
What is the function of the palmaris longus?
Flexes hand at wrist and tenses palmar aponeurosis.
What is the function of the flexor digitorum superficialis?
Flexes middle phalanges of digits 2-5.
What is the function of the flexor retinaculum?
Holds tendons of flexor muscles in place at the wrist.
What is the function of the rectus abdominus?
Flexes vertebral column; compresses abdominal contents.
What is the function of the external oblique?
Compresses abdomen; laterally flexes and rotates vertebral column.
What is the function of the internal oblique?
Compresses abdomen; laterally flexes and rotates vertebral column.
What is the function of the transverse abdominus?
Compresses abdominal contents.
What is the function of the iliacus?
Flexes thigh at hip joint.
What is the function of the psoas major?
Flexes thigh at hip and flexes trunk.
What is the function of the adductor longus?
Adducts and medially rotates thigh.
What is the function of the adductor magnus?
Adducts, flexes, and medially rotates thigh.
What is the function of the adductor brevis?
Adducts and flexes thigh.
What is the function of the gracilis?
Adducts thigh and flexes leg at knee.
What is the function of the tensor fasciae latae?
Abducts and medially rotates thigh; tenses fascia lata.
What is the function of the iliotibial tract (band)?
Stabilizes lateral thigh and knee.
What is the function of the rectus femoris?
Extends leg at knee and flexes thigh at hip.
What is the function of the vastus lateralis?
Extends leg at knee.
What is the function of the vastus intermedius?
Extends leg at knee.
What is the function of the vastus medialis?
Extends leg at knee.
What is the function of the sartorius?
Flexes, abducts, and laterally rotates thigh; flexes knee.
What is the function of the tibialis anterior?
Dorsiflexes and inverts foot.
What is the function of the peroneus (fibularis) longus?
Plantarflexes and everts foot.
What is the function of the peroneus (fibularis) brevis?
Plantarflexes and everts foot.
What is the function of the extensor hallucis longus?
Extends big toe; dorsiflexes foot.
What is the function of the extensor digitorum longus?
Extends toes 2-5; dorsiflexes foot.
What is the function of the extensor retinaculum?
Holds tendons of extensor muscles in place at the ankle.
What is the function of the splenius capitus?
Extends, rotates, and laterally flexes head and neck.
What is the function of the trapezius?
Elevates, retracts, and rotates scapula; extends neck.
What is the function of the triceps brachii?
Extends forearm at elbow.
What is the function of the anconeus?
Assists triceps in extending elbow.
What is the function of the extensor carpi radialis longus?
Extends and abducts wrist.
What is the function of the extensor carpi ulnaris?
Extends and adducts wrist.
What is the function of the extensor digitorum?
Extends fingers and hand at wrist.
What is the function of the extensor pollicis brevis?
Extends proximal phalanx of thumb.
What is the function of the abductor pollicis longus?
Abducts and extends thumb at carpometacarpal joint.
What is the function of the extensor retinaculum?
Holds tendons of extensor muscles in place at the wrist.
What is the function of the supraspinatus?
Abducts arm; stabilizes shoulder joint.
What is the function of the infraspinatus?
Laterally rotates arm; stabilizes shoulder joint.
What is the function of the teres minor?
Laterally rotates arm; stabilizes shoulder joint.
What is the function of the subscapularis?
Medially rotates arm; stabilizes shoulder joint.
What is the function of the teres major?
Adducts, extends, and medially rotates arm.
What is the function of the rhomboid minor?
Retracts and elevates scapula.
What is the function of the rhomboid major?
Retracts and elevates scapula.
What is the function of the levator scapulae?
Elevates scapula and tilts glenoid cavity inferiorly.
What is the function of the latissimus dorsi?
Extends, adducts, and medially rotates arm.
What is the function of the spinalis?
Extends and laterally flexes vertebral column.
What is the function of the longissimus?
Extends and laterally flexes vertebral column; extends head.
What is the function of the iliocostalis?
Extends and laterally flexes vertebral column.
What is the function of the gluteus maximus?
Extends and laterally rotates thigh at hip.
What is the function of the gluteus medius?
Abducts and medially rotates thigh.
What is the function of the gluteus minimus?
Abducts and medially rotates thigh.
What is the function of the piriformis?
Laterally rotates and abducts thigh.
What is the function of the biceps femoris?
Flexes leg at knee; extends thigh at hip.
What is the function of the semitendinosus?
Flexes leg at knee; extends thigh at hip.
What is the function of the semimembranosus?
Flexes leg at knee; extends thigh at hip.
What is the function of the gastrocnemius?
Plantarflexes foot; flexes leg at knee.
What is the function of the soleus?
Plantarflexes foot.
What is the function of the tibialis posterior?
Plantarflexes and inverts foot.
What is the function of the plantaris?
Weakly assists in plantarflexion and knee flexion.
What is the function of the flexor hallucis longus?
Flexes big toe; plantarflexes foot.
What is the function of the flexor digitorum longus?
Flexes toes 2–5; plantarflexes foot.
What is the function of the flexor digitorum brevis?
Flexes toes 2–5 at proximal interphalangeal joints.
What is the origin, insertion, and action of the adductor longus?
Origin: Pubis; Insertion: Linea aspera of femur; Action: Adducts, flexes, and medially rotates thigh.
What is the origin, insertion, and action of the biceps brachii?
Origin: Coracoid process and supraglenoid tubercle of scapula; Insertion: Radial tuberosity; Action: Flexes elbow and supinates forearm.
What is the origin, insertion, and action of the biceps femoris?
Origin: Ischial tuberosity and linea aspera; Insertion: Head of fibula and lateral condyle of tibia; Action: Extends thigh and flexes leg.
What is the origin, insertion, and action of the extensor carpi radialis longus?
Origin: Lateral supracondylar ridge of humerus; Insertion: Base of 2nd metacarpal; Action: Extends and abducts wrist.
What is the origin, insertion, and action of the extensor digitorum longus?
Origin: Lateral condyle of tibia and fibula; Insertion: Middle and distal phalanges of toes 2–5; Action: Extends toes and dorsiflexes foot.
What is the origin, insertion, and action of the extensor hallucis longus?
Origin: Anterior surface of fibula; Insertion: Distal phalanx of big toe; Action: Extends big toe and dorsiflexes foot.
What is the origin, insertion, and action of the flexor carpi radialis?
Origin: Medial epicondyle of humerus; Insertion: Base of 2nd and 3rd metacarpals; Action: Flexes and abducts wrist.
What is the origin, insertion, and action of the gastrocnemius?
Origin: Medial and lateral condyles of femur; Insertion: Calcaneus via Achilles tendon; Action: Plantarflexes foot and flexes knee.
What is the origin, insertion, and action of the gluteus maximus?
Origin: Ilium, sacrum, and coccyx; Insertion: Gluteal tuberosity and iliotibial tract; Action: Extends and laterally rotates thigh.
What is the origin, insertion, and action of the iliacus?
Origin: Iliac fossa; Insertion: Lesser trochanter of femur; Action: Flexes thigh at hip.
What is the origin, insertion, and action of the infraspinatus?
Origin: Infraspinous fossa of scapula; Insertion: Greater tubercle of humerus; Action: Laterally rotates arm.
What is the origin, insertion, and action of the latissimus dorsi?
Origin: Spinous processes of T7–L5, iliac crest, ribs 9–12; Insertion: Intertubercular sulcus of humerus; Action: Extends, adducts, and medially rotates arm.
What is the origin, insertion, and action of the masseter?
Origin: Zygomatic arch; Insertion: Angle and ramus of mandible; Action: Elevates mandible (closes jaw).
What is the origin, insertion, and action of the pectoralis major?
Origin: Clavicle, sternum, and cartilage of ribs 1–6; Insertion: Intertubercular sulcus of humerus; Action: Flexes, adducts, and medially rotates arm.
What is the origin, insertion, and action of the rectus abdominus?
Origin: Pubic crest and symphysis; Insertion: Xiphoid process and costal cartilages of ribs 5–7; Action: Flexes vertebral column and compresses abdomen.
What is the origin, insertion, and action of the rectus femoris?
Origin: Anterior inferior iliac spine; Insertion: Tibial tuberosity via patellar ligament; Action: Extends leg and flexes thigh.
What is the origin, insertion, and action of the rhomboid major?
Origin: Spinous processes of T2–T5; Insertion: Medial border of scapula; Action: Retracts and stabilizes scapula.
What is the origin, insertion, and action of the sartorius?
Origin: Anterior superior iliac spine; Insertion: Medial surface of tibia; Action: Flexes, abducts, and laterally rotates thigh; flexes knee.
What is the origin, insertion, and action of the semimembranosus?
Origin: Ischial tuberosity; Insertion: Medial condyle of tibia; Action: Extends thigh and flexes leg.
What is the origin, insertion, and action of the semitendinosus?
Origin: Ischial tuberosity; Insertion: Medial surface of tibia; Action: Extends thigh and flexes leg.
What is the origin, insertion, and action of the soleus?
Origin: Posterior fibula and tibia; Insertion: Calcaneus via Achilles tendon; Action: Plantarflexes foot.
What is the origin, insertion, and action of the sternocleidomastoid?
Origin: Manubrium and medial clavicle; Insertion: Mastoid process of temporal bone; Action: Flexes neck and rotates head.
What is the origin, insertion, and action of the subscapularis?
Origin: Subscapular fossa of scapula; Insertion: Lesser tubercle of humerus; Action: Medially rotates arm.
What is the origin, insertion, and action of the supraspinatus?
Origin: Supraspinous fossa of scapula; Insertion: Greater tubercle of humerus; Action: Abducts arm.
What is the origin, insertion, and action of the temporalis?
Origin: Temporal fossa; Insertion: Coronoid process of mandible; Action: Elevates and retracts mandible.
What is the origin, insertion, and action of the teres minor?
Origin: Lateral border of scapula; Insertion: Greater tubercle of humerus; Action: Laterally rotates arm.
What is the origin, insertion, and action of the tibialis anterior?
Origin: Lateral condyle and upper tibia; Insertion: First metatarsal and medial cuneiform; Action: Dorsiflexes and inverts foot.
What is the origin, insertion, and action of the trapezius?
Origin: Occipital bone, nuchal ligament, and spinous processes of C7–T12; Insertion: Clavicle, acromion, and spine of scapula; Action: Elevates, retracts, and rotates scapula.
What is the origin, insertion, and action of the triceps brachii?
Origin: Infraglenoid tubercle of scapula and posterior humerus; Insertion: Olecranon of ulna; Action: Extends forearm at elbow.
Nervous System
What are the three basic steps the nervous system uses to carry out coordinating tasks?
- Receives stimuli and transmits it to the CNS
- CNS processes the information and determines response
- CNS issues commands primarily to muscle and endocrine system.
Nervous System
What is the CNS and what does is consist of?
Central Nervous System. Consists of the brain and spinal cord.
Nervous System
What is the function of the CNS?
decision-making functions of the nervous system
Nervous System
What is the PNS? What does it consist of?
Peripheral nervous system. Consists of everything other than the brain and spinal cord.
Nervous System
What is a ganglion?
A knotlike swelling in a nerve where the cell bodes of the PSN neurons are concentrated.
Nervous System
What are the sub divisions of the PNS?
- Sensory
- Motor
Nervous System
What are the subdivisions of the Sensory and Motor divisions of the PNS?
- Sensory (afferent) division
a. Somatic sensory division
b. Visceral sensory division - Motor (efferent) division
a. Somatic motor division
b. Visceral motor division
Just remember somatic and visceral for each
Nervous System
What does the somatic sensory division do?
carries stimuli from receptors in the skin, muscle, bones, and joints to the CNS.
Nervous System
What does the visceral sensory division do?
carries stimuli mainly from the viscera of the thoracic and abdominal cavities to the CNS: heart, lungs, stomach, bladder, etc.
Nervous System
What does the somatic motor division do?
carries signals from the CNS to the skeletal muscles. This includes voluntary muscle contractions and automatic reflexes.
Nervous System
What does the visceral motor division do?
carries signals from the CNS to glands, cardiac muscle, and smooth muscle. There is typically no voluntary control over these effectors.
Nervous System
What is another name for the visceral motor division?
autonomic nervous system, or ANS
Nervous System
What are the subdivisions of the visceral motor division?
- sympathetic division
- parasympathetic division
- enteric plexus
Nervous System
What does the sympathic division of the visceral motor division do?
arouses the body for action. Accelerating heart rate, increasing respiration, etc. Inhibits digestion and reduces urine production.
Nervous System
What does the parasympathetic division of the visceral motor division do?
tends to have a calming effect. Slowing heart rate, etc. Stimulates digestion
Nervous System
What does the enteric plexus division of the visceral motor division do?
The entric plexus lies in the wall of the digestive tract and is composed of more neurons than the spinal cord. This system enables different regions of the GI tract to communicate and coordinate their motility and secretion.
Discussed later, just remember it has to do with GI coordination.
Nervous System
What are the three functional classes of neurons?
- Sensory (afferent) neurons
- Interneurons
- Motor (efferent) neurons
Nervous System
The cytoplasm of a neuron.
axoplasm
Nervous System
cell membrane of a neuron
axolemma
Nervous System
An extensive complex of fine branches at the distal end of a neuron.
terminal arborization
Nervous System
non-neuronal support cells
Neuroglia or glial cells
Nervous System
What are the six types of neuroglia?
- Oligodendrocytes
- Ependymal cells
- Microglia
- Astrocytes
- Schwann cells
- Satellite cells
Nervous System
What is the function of oligodendrocytes?
Form myelin in brain and spinal cord.
Nervous System
What is the function of ependymal cells?
Line cavities of brain and spinal cord; secrete and circulate cerebrospinal fluid
Nervous System
What is the function of microglia?
Phagocytize and destroy microorganisms, foreign matter, and dead nervous tissue.
Nervous System
What is the function of astrocytes?
- Cover the brain surface and nonsynaptic regions of neurons.
- form supportive framework in CNS
- induce formation of blood-brain barrier
- nourish neurons
- stimulate neurons for growth
- promotes the formation of synapses and neural circuitry
- remove potassium ions and other neurotransmitters from ECF of CNS
- forms scar tissue for damaged nervous cells
Nervous System
What is the function of schwann cells?
Form neurolemma around all PNS axons and myelin around most of them
Also aides in regeneration of damaged nerves
Nervous System
What is the function of satellite cells?
surround the nerve cell bodies in ganglia of the PNS
provide insulation around the cell bodyh and regulate the chemical environment of the neurons
Nervous System
What is a myelin sheath?
spiral layers of insulation around an axon; formed by schwann cells.
Nervous System
The gap between segments of myelin sheath.
node of Ranvier
Nervous System
myelin-covered segments of the axon
internodal segments
Nervous System
Important Note: Resting membrane potential (RMP), function of ATP, sodium potassium pumps, etc. has already been covered and will not be in the flashcards. Please carefully review 12.4 of the textbook.
Learn about RMP, depolarization, local potentials, action potentials, etc.
Nervous System
Fibrous membranes of the CNS.
meninges (singular: meninx)
Nervous System
What are the three meninges?
From superficial to deep:
1. dura mater
2. arachnoid mater
3. pia mater
Nervous System
Forms a loose-fitting sleeve around the spinal cord.
Dura mater; dural sheath
Nervous System
consists of five or six layers of squamous to cuboidal cells adhering to the inside of the dura.
arachnoid mater
Nervous System
Loose array of cells and collagenous and elastic fibers spanning the gap between the arachnoid membrane and pia matter.
subarachnoid space
Nervous System
Where is cerebrospinal fluid located?
Within the subarachnoid space
Nervous System
A delicate, transparent membrane that follows the contour of the spinal cord; composed of one or two layers of squamous to cuboidal cells and delicate collagenous and elastic fibers
Pia mater
Nervous System
The gap between two neurons where they meet.
synaptic cleft
Nervous System
Which neurotransmitter is described by the following:
Location
Neuromuscular junctions
autonomic nervous system synapses
retina
many parts of the brain
Action
excites skeletal muscle
inhibits cardiac muscle
excitatory/inhibitory effect on smooth muscle and glands depending on location
acetylcholine (ACh)
Nervous System
What are the categories of neurotransmitters?
- acetylcholine
- amino acids
- monoamines
- neuropeptides
- purines (like ATP)
- gases (NO and CO2)
Nervous System
Which neurotransmitter is described by the following:
Location
cerebral cortex
brainstem
Action
accounts for about 75% of all excitatory synaptic transmission in the brain
involved in learning and memory
glutamate
Nervous System
Which neurotransmitter is described by the following:
Location
spinal cord
Action
similar to glutamate (excitatory)
aspartate
Nervous System
Which neurotransmitter is described by the following:
Location
inhibitory neurons of the:
brain
spinal cord
retina
Action
most common inhibitory neurotransmitter in the spinal cord
glycine
Nervous System
Which neurotransmitter is described by the following:
Location
thalamus
hyptothalamus
cerebellum
occipital lobes of cerebrum
retina
Action
The most common inhibitory neurotransmitter in the brain.
GABA
Nervous System
What type of neurotransmitter is glutamate?
amino acid
Nervous System
What type of neurotransmitter is aspartate?
amino acid
Nervous System
What type of neurotransmitter is glycine?
amino acid
Nervous System
What type of neurotransmitter is GABA?
amino acid
Nervous System
What type of neurotransmitter is norepinephrine?
monoamine
Nervous System
What type of neurotransmitter is epinephrine?
monoamine
Nervous System
What type of neurotransmitter is dopamine?
monoamine
Nervous System
What type of neurotransmitter is serotonin?
monoamine
Nervous System
What type of neurotransmitter is histamine?
monoamine
Nervous System
What type of neurotransmitter is substance p?
neuropeptide
Nervous System
What type of neurotransmitter is enkephalins?
neuropeptide
Nervous System
What type of neurotransmitter is beta-endorphin?
neuropeptide
Nervous System
What type of neurotransmitter is cholecystokinin?
neuropeptide
Nervous System
Which neurotransmitter is described by the following:
Location
sympathetic nervous system
cerebral cortex
hypothalamus
brainstem
cerebellum
spinal cord
Action
involved in dreaming
walking
mood
excites cardiac muscle
excites/inhibits smooth muscle depending on location
norepinephrine
Nervous System
Which neurotransmitter is described by the following:
Location
hypothalamus
thalamus
spinal cord
adrenal medulla
Action
involved in dreaming
walking
mood
excites cardiac muscle
excites/inhibits smooth muscle depending on location
epinephrine
Nervous System
Which neurotransmitter is described by the following:
Location
hypothalamus
limbic system
cerebral cortex
retina
highly concentrated in substantia nigra of midbrain
Action
elevation of mood
control of skeletal muscle
dopamine
Nervous System
Which neurotransmitter is described by the following:
Location
hypothalamus
limbic system
cerebellum
retina
spinal cord
blood platelets
intestinal cells, particularly microbiota
Action
sleepiness
alertness
thermoregulation
mood
behavior
serotonin
Nervous System
Which neurotransmitter is described by the following:
Location
hypothalamus
mast cells of connective tissue
basophils in blood
Action
vasodilator
histamine
Nervous System
Which neurotransmitter is described by the following:
Location
base nuclei
midbrain
hypothalamus
cerebral cortex
small intestine
pain receptor neurons
Action
pain transmission
Substance P
Nervous System
Which neurotransmitter is described by the following:
Location
hypothalamus
limbic system
pituitary
pain pathways of spinal cord
nerve endings in digestive tract
Action
analgesic - antagonistic to substance p
inhibit intestinal motility
modulate immune responses
enkephalins
Nervous System
Which neurotransmitter is described by the following:
Location
digestive tract
spinal cord
many parts of the brain
hormone secreted by pituitary into the blood
Action
analgesic
labor and delivery feedback
response to pain
beta-endorphin
Nervous System
Which neurotransmitter is described by the following:
Location
cerebral cortex
small intestines
Action
suppresses appetite
cholecystokinin
Nervous System
What is a first-order neuron?
detects a stimulus and conducts a signal to the CNS
Nervous System
What is a second-order neuron?
conducts a signal to the thalamus at the upper end of the brainstem.
Nervous System
What is a third-order neuron?
Carries a signal to the cerebral cortex.
Nervous System
What is an ascending tract of the spinal cord?
sections of the spinal cord that carries sensory signals to the brain.
Nervous System
What are the six major ascending tracts of the spinal cord?
- cuneate fasciculus (posterior funiculus)
- gracile fasciculus (posterior funiculus)
- spinothalamic tract
- spinoreticular tract
- posterior spinocerebellar tract
- anterior spinocerebellar tract
Nervous System
What spinal cord tract is described by the following?:
Funiculus
posterior
Decussation
in medulla
Functions
sensations of limb, trunk, and movement
deep touch
visceral pain
vibration
below T6
gracile fasciculus
Nervous System
What spinal cord tract is described by the following?:
Funiculus
posterior
Decussation
in medulla
Functions
sensations of limb, trunk, and movement
deep touch
visceral pain
vibration
above T6
cuneate fasciculus
Nervous System
What spinal cord tract is described by the following?:
Funiculus
lateral
anterior
Decussation
in spinal cord
Functions
sensations of light touch
tickle
itch
temperature
pain
pressure
spinothalamic
Nervous System
What spinal cord tract is described by the following?:
Funiculus
lateral
anterior
Decussation
in spinal cord
Functions
sensations of pain from tissue injury
spinoreticular
Nervous System
What spinal cord tract is described by the following?:
Funiculus
lateral
Decussation
none
Functions
feedback from muscles (proprioception)
posterior spinocerebellar
Nervous System
What spinal cord tract is described by the following?:
Funiculus
lateral
Decussation
in spinal cord
Functions
feedback from muscles (proprioception)
anterior spinocerebellar
Nervous System
What spinal cord tract is described by the following?:
Funiculus
lateral
Decussation
in medulla
Functions
fine control of limbs
lateral corticospinal
Nervous System
What spinal cord tract is described by the following?:
Funiculus
lateral
Decussation
in spinal cord
Functions
fine control of limbs
anterior corticospinal
Nervous System
What spinal cord tract is described by the following?:
Funiculus
anterior
Decussation
in midbrain
Functions
reflexive head turning in response to visual and auditory stimuli.
tectospinal
Nervous System
What spinal cord tract is described by the following?:
Funiculus
lateral
Decussation
none
Functions
balance and posture
regulation of the awareness of pain
lateral reticulospinal
Nervous System
What spinal cord tract is described by the following?:
Funiculus
anterior
Decussation
none
Functions
balance and posture
regulation of the awareness of pain
medial reticulospinal
Nervous System
What spinal cord tract is described by the following?:
Funiculus
anterior
Decussation
none
Functions
balance and posture
lateral vertibulospinal
Nervous System
What spinal cord tract is described by the following?:
Funiculus
anterior
Decussation
in medulla
Functions
control of head position
medial vestibulospinal
Nervous System
External to the neurolemma, each fiber is surrounded by a basal lamina and then a thin sleeve of loose connective tissue called what?
endoneurium
Nervous System
Like muscles, nerves are gathered into bundles called fascicles, each fascicle is wrapped in a sheath called what?
perineurium
Nervous System
Several nerve fascicles are bundled together into a whole nerve and wrapped by an outer membrane called what?
epineurium
Nervous System
Carry sensory signals from receptors to the CNS
afferent fibers
Nervous System
Carry motor signals from the CNS to effectors
efferent fibers
Nervous System
innervate skin, skeletal muscle, bones, and joints
somatic fibers
Nervous System
innervate blood vessels, glands, and internal organs
visceral fibers
Nervous System
innervate widespread organs such as muscles, skin, glands, viscera, and blood vessels
general fibers
Nervous System
innervate more localized organs in the head, including the eyes, ears, olfactory and taste receptors, and muscles of chewing, swallowing, and facial expression
special fibers
Nervous System
What type of fibers to motor nerves contain?
only efferent fibers
Nervous System
What types of fibers are contained in sensory nerves?
only afferent fibers
Nervous System
What is the most common type of nerve and what type of fibers do they contain?
mixed nerves that contain both afferent and efferent fibers.
Nervous System
What is a ganglion?
A cluster of nerve cell bodies that resembles a knot in a string (nerve). They only exist outside of the CNS.
Nervous System
What are the sets of the 31 pairs of spinal nerves and how many are in each set?
- 8 cervical (C1-C8)
- 12 thoracic (T1-T12)
- 5 lumbar (L1-L5)
- 5 sacral (S1-S5)
- 1 coccygeal (Co1)
Nervous System
Where are each set spinal nerves (nerves leaving/entering the CNS) located in reference to each vertebra?
- C1-C7 nerves are located superior to vertebrae C1-C7
- nerve C8 (there is no vertebra C8) is located inferior to C7 and superior to T1
- all nerves below C8 are located inferior to the corresponding vertebra: nerve L3 is inferior to the L3 vertebra.
Just remember that the transition happens with nerve C8 between vertebrae C7 and T1.
Nervous System
What is a plexus?
A web of nerves that combine and diverge near the nerve roots.
Note that nerve roots in image are the spinal nerves, they then form a plexus by converging and diverging resulting in a new set of nerves after the plexus.
Nervous System
The reflexes of skeletal muscles
somatic reflexes
Nervous System
What are the four important properties of a reflex?
- require stimulation - not ticks
- quick
- involuntary
- stereotyped - happen the same way every time; predictable
Nervous System
List the 5 steps of the reflex arc
- somatic receptors
- afferent nerve fibers
- integration center
- efferent nerve fibers
- effectors
Nervous System
Somatic reflex stretch receptor
muscle spindles
Nervous System
modified muscle fibers within the muscle spindle
intrafusal fibers
These are NOT nerve fibers, they are muscle fibers
Nervous System
Type of motor neuron that innervates intrafusal fibers of muscle spindles.
gamma motor neuron
make up nearly one-third of all spinal motor neurons
Nervous System
Type of neuron that innervates extrafusal fibers (non-spindle) of muscle.
alpha motor neurons
Nervous System
When a muscle is suddenly stretched, it “fights back”. What is this type of reflex called?
myotatic (stretch) reflex
Nervous System
What are myotatic reflexes important?
They help maintain posture and equilibrium reflexively.
Continual, subtle adjustments via the myotatic reflex arc keeps your head generally erect throughout most of your waking hours without realizing it.
Nervous System
The quick contraction of flexor muscles resulting in the withdrawal of a limb from an injurious stimulus.
flexor reflex
Nervous System
The contraction of extensor muscles in the limb opposite from the one that experiences a flexor reflex.
crossed extension reflex
Nervous System
What part of the CNS unconciously maintains balance, coordination, center of gravity shifts, etc?
Mostly the cerebellum and some of the cerebral cortex
Nervous System
A reflex in which the sensory input and motor output are on the same side of the spinal cord.
example: patellar reflex or flexor reflex
ipsilateral reflex arc
Nervous System
Reflex arc in which the input and output are on opposite sides of the spinal cord.
contralateral reflex arc
Nervous System
A reflex arc in which the input and output occur at different levels (segments) of the spinal cord
example: pain in the foot causes contractions of abdominal muscles
intersegmental reflex arc
Nervous System
Proprioceptors located in a tendon near its junction with a muscle. Provides feedback on the degree of muscle tension at the joint.
Tendon organs
Nervous System
A reflex response to excessive tension on the tendon.
involuntary IPSP of alpha motor neurons
tendon reflex
Nervous System
What tissue called that lines the floor and wall of each ventricle of the brain?
choroid plexus
CO-royd
named after the histological resemblance to the fetal chorion
Nervous System
What produces cerebrospinal fluid (CSF)?
choroid plexus
found within brain ventricles
Nervous System
clear, colorless liquid that fills the ventricles and canals of the CNS and bathes its external surfaces.
cerebrospinal fluid (CSF)
Nervous System
what drives CSF circulation?
- beating of ependymal cells
- its own pressure
- rhythmic pulsations of the brain produced by each heartbeat
Nervous System
What are the main functions of CSF?
- bouyancy
- protection
- chemical stability
Nervous System
Where is CSF reabsorbed into the venous blood?
dural venous sinuses
Nervous System
How many cranial nerves are there and how are they numbered?
twelve,
CN I through CN XII
Nervous System
Which cranial nerves carry signals only from outlying sense organs to the brain?
CN I and II
Nervous System
Which cranial nerves only carry from the brainstem to outlying muscles and glands?
CN III, IV, VI, XI, and XII
Nervous System
Which cranial nerves are mixed–carry signals both ways?
V, VII, VIII, IX, and X
Nervous System
Which cranial nerve is the olfactory nerve?
CN I
Nervous System
What is the function of the olefactory nerve (CN I)?
A purely sensory nerve for smell.
Nervous System
Which CN is the optic nerve?
CN II
Nervous System
What is the function of the optic nerve (CN II)?
CN II is a purely sensory nerve which carries all visual information from the retina to the brain.
Nervous System
Which CNs are associated with the eyes, both affectors and effectors?
CN II, III, IV, and VI
Not V
Nervous System
Which CN is the oculomotor nerve?
CN III
Nervous System
What is the function of the oculomotor nerve (CN III)?
Controls four of the six muscles of eye movement. Controls pupil size and control, eyelid, and focusing.
Nervous System
Which CN is the trochlear nerve?
CN IV
Nervous System
What is the function of the trochlear nerve (CN IV)?
Controls ability to look downward.
Nervous System
Which CN is the trigeminal nerve?
CN V
Nervous System
What is the trigeminal nerve (CN V) responsible for?
CN V is mixed and responsible for sensation and motor function of the face, frontalis, nasal, maxilla, and mandible.
Nervous System
What are the three subdivisions for which the trigeminal nerve is named?
- opthalmic division - CN V_1
- maxillary division - CN V_2
- mandibular division - CN V_3
Nervous System
What nerves are typically targeted for local anesthesia by dentists?
Distal portions of the maxillary and mandibular divisions of the trigeminal nerve (CN V_2 and CN V_3). More specifically the superior and inferior alveolar nerves.
Nervous Systerm
Which CN is the abducens nerve?
(ab-DOO-senz)
CN VI
Nervous System
What is the function of the abducens nerve (CN VI)?
Lateral motion of the eyes. Controls the lateral rectus muscle.
Nervous System
What is the CN of the facial nerve?
CN VII
Nervous System
What is the function of the facial nerve (CN VII)?
CN VII is a mixed nerve
* major motor nerve to the facial muscles.
* sensory fibers for taste buds for the anterior two-thirds of the tongue.
It has five major branches throughout the face. Study figure below.
Nervous System
What CN is the vestibulocochlear nerve?
(vess-TIB-you-lo-COC-lee-ur)
CN VIII
Nervous System
What is the function of the vestibulocochlear nerve (CN VIII)?
CN VIII is a mixed nerve:
* major sensory nerve of hearing and equilibrium
* motor effector on the inner ear to tune sense of hearing
Nervous System
What is the CN of the glossopharyngeal nerve?
(GLOSS-oh-fah-RIN-jee-ul)
CN IX
Nervous System
What is the function of the glossopharyngeal nerve (CN IX)?
CN IX is a complex mixed nerve, only briefly covered here:
* sensation in the tongue, throat, outer ear, gag reflex, and even some cardiovascular and repiratory functions
* motor functions of the same
There is a WHOLE LOT to this nerve, but we only need to know the basic regions it covers.
Nervous System
What is the CN of the vagus nerve?
(VAY-gus)
CN X
Nervous System
What is the function of the vagus nerve (CN X)?
CN X is a mixed nerve.
Major roles in the control and sensation of cardiac, pulmonary, digestive, and urinary functions. Also carries somatic nerves to several muscles of the head and neckm as well as 90% of all fibers to the parasympathetic nervous system (PNS).
CN X is the major PNS nerve
Nervous System
What is the CN of the accessory nerve?
I can pronouce this one!!
CN XI
Nervous System
What is the function of the accessory nerve (CN XI)?
CN XI is a motor nerve that controls swallowing and some neck and shoulder muscles.
Interesting note: CN XI is not a true cranial nerve as it does not arise from the brain, but from the upper spinal cord, enters the cranial cavity through the foramen magnum, then exists again through the jugular foramen, bundled with the vagus and glossopharyngeal nerves.
Nervous System
What is the CN of the hypoglossal nerve?
(HY-po-GLOSS-ul)
CN XII
Nervous System
What is the function of the hypoglossal nerve (CN XII)?
CN XII is a motor nerve that controls the tongue movements for speech, food manipulation, and swallowing. Makes it possible to protrude the tongue.
Nervous System
Quick note on learning CNs, if it’s helpful:
Old Opie occasionally tries trigonometry and feels very gloomy, vague,. and hypoactive.
olfactory (I), optic (II) oculomotor (III), trochlear (IV), trigeminal (V), abducens (VI), facial (VII), vestibulocochlear (VIII), glossopharyngeal (IX), vagus (X), accessory (XI), hypoglossal (XII)
Nervous System
Where is the gracile fasciculus located?
It is part of the posterior funiculus on the right, posterior side of spinal white mater.
Nervous System
Where is the cuneate fasciculus located?
It is part of the posterior funiculus on the right, posterior side of spinal white mater.
