Exam 2 Flashcards
agonists
prime movers, supination to flexion
antagonists
ex: triceps brachii
Synergist
helps the agonist, synergizes movement
Fixator
fixating joint that is proximal to joint you are moving at ex: deltoid, rhomboid
organizations of fasicles
parellel, circular, convergent
pennate:
short fibers are obliquely attached to tendon providing tension or force
unipennate
one pennation angle along fascicles
bipennate
long axis in middle 2 sides of pennation
multipennate
many pennations at different longitudinal axis
flexion
decrease angle
extension
increase angle
abduction
movement away from midline of body
adduction
movement towards midline of body
circumduction
combination of extension flexion abduction and adduction, moving in a circle
lateral rotation / medial rotation
pivoting along a long axis ex: in humerus
pronation / supination
involves forearm,
pronation = palms down
supination=palms up
dorsiflexion / plantar flexion
specific to ankle joint
bring dorsum towards leg
plantar = going on tip toes
inversion / eversion
specific to ankle joint
inversion: bring sole toward midline
eversion = bring sole of foot away from midline
protraction / retraction
specific to mandible but can occur in other parts
protraction: bringing mandible out
retraction: bringing it back in
depression / elevation
specific to mandible
depression: bringing jaw down
elevation= bringing jaw up
opposition / reposition
opposition bringing thumb and index finger together
muscles of mastication
masseter, temporalis, medial pterygoid, lateral pterygoid
biceps brachii
origin: supraglenoid tubercle, coracoid process
insertion: radial tuberosity
help flex elbow joint
Brachialis
help flex elbow joint
brachioradialis
help flex elbow joint
triceps brachii
origin: infraglenoid tubercle, posterior shaft of humerus
insertion: olecranon process
Muscles acting at the elbow
biceps brachii, brachialis, brachioradialis, triceps brachii, anconeus
Rotator cuff muscle
lateral rotators of humerus
abductor of the humerus
medial rotator of the humerus
lateral rotators of humerus
infraspinatus, teres major
abductor of humerus
supraspinatus: abductor
medial rotator of humerus
subscapularis
Muscles acting at the shoulder
should adductors / flexors, shoulder adductors, shoulder abductor,
shoulder adductors/flexors
bring limb toward midline, anterior to shoulder joint
coracobrachialis
pectoralis major
Shoulder adductors
extensors, posterior to shoulder joint, teres major latissimus dorsi
shoulder abductor
can also flex and extend the shoulder, deltoid helps the supraspinatus muscle with flexion, 3 bellies can help with flexion and extension of shoulder joint
Muscles acting at knee
knee extensors, knee flexors
knee extensors
common insertion: tibial tuberosity help with extension Vastus lateralis Vastus medialis Rectus femoris Vastus intermedius
Knee flexors
Common origin: ischial tuberosity Hamstrings made of 3 muscles Biceps femoris Semimembranosus Semitendinosus (more posterior)
Muscles acting at the hip
hip adductors, hip abductors, hip flexors, hip extensors
hip adductors
Adductor longus Pectineus Adductor brevis Adductor magnus Gracilis
Hip abductors
gluteus medius
gluteus minimus
hip flexors
iliopsoas (psoas major and iliacus)
rectus femoris
hip extensors
Gluetus maximus
Semitendinosus
Biceps femoris (long head)
Semimembranosus
Muscular dystrophy
Inherited group of muscle disorders
Skeletal muscle degenerates and is replaced by adipose and fibrous connective tissue
Most common and serious form is Duchenne muscular dystrophy
– X-linked recessive gene
– 1 in 3500 births, mostly male
– Lacks protein called dystrophin
basic properties of muscular tissue
Excitability: electrical impulses sent to the muscle cell, and muscle cells respond to the stimulus
Contractility: once stimulated its able to shorten or contract
Elasticity: when stretched or lengthened, it will go back to original shape and length
Extensibility: lengthening of the muscle
Cardiac muscle characteristics
Found in heart myocardium
“Y” shaped or branched fibers
Uninucleate or binucleate
Intercalated discs (where gap junctions are, and desmosomes make up disk) Desmosomes hold cells together, gap junctions allow things to pass through
Striated
Auto-rhythmic: can contract without stimulus of nervous system (this ability comes from intercalated discs)
Involuntary
Smooth muscle
Found in walls of visceral organs, GI tract Fusiform shape (football) Uninucleate No striations Fatigue resistant Involuntary
skeletal muscle
Large cylindrical shape Multinucleated : (myoblast in embryonic development fuse together and nuclei remain intact and now they are one cell) Formed from the fusion of myoblasts Innervated at neuromuscular junctions Long cylindrical Striated Voluntary
Vascular
functions of skeletal muscle
Movement
Maintenance of posture
Temperature regulation
Storage and movement of materials
Support abdominal organs
Joint stabilization
endomysium
wraps muscle cells (muscle fibers)
perimysium
wraps fascicles
epimysium
wraps entire muscles
deep fascia
wraps muscle group
tendon
attach muscle to bone
muscle cells (fibers)
smallest unit make up muscle fascicles
fascicles
bundles of muscle fibers, make up entire organs
blood vessels
provide nourishment oxygen delivery and waste removal to the skeletal and other muscles
nerves
attaches to muscles at neuromuscular junction
aponeurosis
flat tendon that attaches muscle to bone
origin
less moveable attachment site
insertion
moveable attachment site
neuromuscular junction
site where a motor neuron meets a muscle cell and innervates the muscle
sarcolemma
plasma membrane of of the muscle fiber
sarcoplasm
cytoplasm
T-tubules
extension of the sarcolemma surrounding myofibril
sarcoplasmic reticulum
endoplasmic reticulum for muscle cells stores, releases, and retrieves calcium ions
terminal cisternae
portion of the sarcoplasmic reticulum that is near T-tubules, releases calcium
myofibrils:
tubelike structure in muscle cell, Chains of sarcomeres are linked together runs the entire length of the muscle fiber and attaches to the sarcolemma Contains thick and thin filaments, functional unit of contraction
sarcomeres
functional unit of cell, (where contraction and relaxation take place, contain filaments within them (thick filaments, and thin actin filaments), defined by Z-disk borders (edges) end of one sarcomere and beginning of next
Thick: myosin filament, myosin head
Thin: actin filament, actin binding site
M-line: middle line of sarcomere
When binding occurs the Z-discs move closer to the M-line
thick filament
myosin
thin filament
actin
troponin
lock keeps tropomyosin to binding sites
tropomyosin
chain that blocks actin binding sites
motor end plate
specific part of sarcolemma
Ach
acetyl choline is a neurotransmitter released from the synapse (synaptic vesicle), to initiate muscle contraction
Rigor Mortis
Death is not an event but a process
Tissues continue to live after the brain, heart and lungs fail
A few hours after death, ATP runs out
Myosin cannot detach from actin
Calcium cannot be taken up by sarcoplasmic reticulum
This leads to the continual muscle contraction of rigor mortis
After 15-24 hours the myofibrils begin to deteriorate allowing muscles to relax
tetanus
Caused by the bacterium Clostridium tetani
Excessive muscle contraction
botulism
Caused by the bacterium Clostridium botulinum
Muscular paralysis
Botox
CNS
Central nervous system
-brain and spinal cord
PNS
peripheral nervous system
ganglion nerve
afferent
information being carried towards
arrive, neurons grouped together neuronal network, sensory, dorsal root ganglion
efferent
information being carried away
motor
ventral root
sensation
sensory receptors detect stimuli afferent information sent to CNS
includes: special senses, somatic senses, visceral senses
special senses
vision, hearing, taste, smell, balance / equilibrium
somatic senses
information from skin joints and skeletal muscles
visceral senses
information from internal organs and blood vessels
Response (motor)
efferent information leaves CNS effectors (muscles or glands) respond
includes somatic nervous system and autonomic nervous system
somatic nervous system
“voluntary” innervates skeletal muscle
autonomic nervous system
“involuntary” innervates cardiac muscle, smooth muscle, and glands
neurons
excitable functional cells that transmit nerve impulses
glial cells
non-excitable cells that support and protect the neurons, in both central and peripheral nervous system
dendrites
take information to the cell body
cell body (soma)
the cell body contains the nucleus and most of the major organelles
axon hillock
most proximal part of axon where electrical impulse travels
axon
a fiber that emerges from the cell body and projects to target cells. That single axon can branch repeatedly to carry nerve impulses to many target cells
myelin sheath
made from glial cells, myelin acts as insulation much like the plastic or rubber that is used to insulate electrical wires. a key difference between myelin and the insulation on a wire is that there are gaps in the myelin covering of an axon
oligodendrocyte
type of glial cell produces myelin sheath
synapses
neuron-neuron contact
nodes of Ranvier
gap between myelin sheets important to the way that electrical signals travel down the axon
Axon terminals
make the connections with target cells at synapses
astrocytes
control ionic external environment induce formation of the blood brain barrier,
Myelin
fatty substance made up of cells
structure: made by oligodendrocytes in the CNS and Schwann cells in the PNS
white fatty coating around axons
helps produce nodes of Ranvier
function: supports protects and insulates axon increases speed of conduction
Gray matter
contains neuron cell bodies and dendrites nuclei, cell body and dendrytes
white matter
contains neuron axons and myelin sheaths axons surrounded by myelin
ganglia
where neuron cell bodies and dendrites are found in the PNS
nerves
neuron axons found here in the PNS
sensory neurons
send information to CNS afferent
motor neurons
sends information away from CNS in PNS
Nerve differences than neurons
cable like bundles of axons in the PNS
endoneurium wraps individual axons made up of connective tissue
perineurium: wraps axon fascicles
epineurium: wraps entire nerves
multiple sclerosis
Patches of myelin in brain and spinal cord destroyed
Autoimmune disease
Symptoms: blindness, weakness, numbness
Alzheimer’s disease
Progressive degenerative disease of the brain
Symptoms: Memory loss, depression, disorientation
Associated with abnormal protein aggregates: Intracellular tau tangles Extracellular amyloid plaques
peripheral nerve regeneration
Body’s ability to repair itself, if we sever a nerve we can regrow it
Shwann cells help with this
Examples: arm falling asleep, severing nerve,
Anencephaly
Disorder at the cranial end of the neural tube
Substantial or complete absence of a brain
Infants rarely live longer than a few hours following birth
Usually detected with prenatal ultrasound
spina bifida
Disorder at the caudal end of the neural tube
Vertebral arch is not fully formed
May be mild (occulta) or severe (meningocele or myelomeningocele)
Sufficient dietary folic acid prevents spina bifida
Types: spina bifida occulta (least severe), meningocele, myelomeningocele (most severe)
meninges
Structure
Connective tissues surrounding the brain and spinal cord
Dura, arachnoid, and pia maters
Function
Separate brain from skull
Enclose and protect blood vessels supplying brain
Contain and circulate cerebrospinal fluid
Cerebral Spinal fluid
Functions Buoyancy Protection (cushion) Environmental stability Location and Composition Produced in the choroid plexus Clear, colorless fluid Circulates through the ventricles and subarachnoid space surrounding the CNS
hydrocephalus
Definition: Excessive CSF Causes: Obstruction of CSF flow Overproduction of CSF Impaired drainage of CSF Treatments: Ventriculoperitoneal shunt Endoscopic third ventriculostomy
cerebrum
Location of conscious thought processes and complex intellectual functions
Two hemispheres (connected by the corpus callosum)
Gyri and sulci increase the surface area (more cortex)
Gray matter and white matter
Lobes of Cerebrum
Frontal lobe: Decision making, personality, verbal communication, voluntary motor control of skeletal muscles
Parietal lobe: Sensory interpretation of textures and shapes, understanding speech
Temporal lobe: Auditory and olfactory experience
Occipital lobe: Vision
Insula: Taste
Cerebellum
Functions
Fine-tunes, smoothens and coordinates muscle movements
Balance/equilibrium
brain stem
Bidirectional passageway between cerebrum and spinal cord
Contains many autonomic and reflex centers essential for survival
Point of attachment for cranial nerves
Medulla
Cardiac center Vasomotor center Respiratory center Reflexes Coughing, sneezing, gagging, vomiting etc.
Limbic System
“Emotional brain”
Involved in emotion, memory and motivation
Dermatomes
A specific segment of skin supplied by a single pair of spinal nerves
nerve plexuses
• Networks of interweaving spinal nerves • Split into multiple “named” nerves that innervate various body structures • Principal plexuses – Cervical – Brachial – Lumbar – Sacral
Cervical plexus
• Spinal nerves C1-C4 • Innervates the anterior neck and parts of the head and shoulder • The phrenic nerve innervates the diaphragm
brachial plexus
Spinal nerves C5-T1
• Innervates the pectoral
girdle and upper limb
lumbosacral plexus
Lumbar Plexus • Spinal nerves L1-L4 • Innervates the anterior and medial thigh Sacral Plexus • Spinal nerves L4-S4 • Innervates all of the lower limb except the anterior/medial thigh
monosynaptic reflexes
The simplest of all reflexes • The stretch reflex is an example (patellar or knee-jerk reflex)
polysynaptic reflexes
More complex neural pathway • Includes interneurons • The withdrawal reflex is an example
somatic nervous system
- One motor neuron to target
- Innervates skeletal muscle
autonomic nervous system
- Chain of two motor neurons to target
- Preganglionic and postganglionic neurons
- Innervates cardiac muscle, smooth muscle & glands
- Divided into sympathetic & parasympathetic divisions
sympathetic divisions
Preganglionic axons synapse in sympathetic ganglia
• Sympathetic ganglia are near the CNS and vertebral column
(called sympathetic chain ganglia and prevertebral ganglia) Functions
• “Fight or Flight”
• Activated in emergency
situations and when
excited or stressed
Exit from CNS
• Thoracic and lumbar
spinal cord
parasympathetic division
• Preganglionic axons synapse in parasympathetic ganglia
• Parasympathetic ganglia are near or within the target organ
(called terminal or intramural ganglia) Functions
• “Rest and Digest”
• Conserves energy and
replenishes energy stores
Exit from CNS:
• Brainstem (CN III,VII,IX,X)
• Sacral spinal cord
Enteric Nervous system
• Large network of neurons in the wall of the digestive tract (contains as many neurons as the spinal cord) • Functions to automatically control digestive system functions • Can be influenced by the ANS, but can also operate independently of the brain and spinal cord
General Senses
(temperature, pain, touch, stretch, and pressure)
special senses
(gustation, olfaction, vision, equilibrium, and audition)
endocrine glands
are ductless glands that secrete hormones directly into the bloodstream, slow effect, long term
hormones
are carried throughout the body by the bloodstream - initiate specific actions in target cells (cells that have receptors for the hormone
tropic hormones
Hormones that affect the release of other hormones
Ex. Gonadotropins (LH and FSH) are hormones that affect the release of sex hormones from the gonads
endocrine system
acts using hormones
can affect any cell in the body (target cells have hormone receptors)
has widespread effects
has slower but longer lasting responses
more long lasting, slower
amine hormone
modified amino acid ex: norepinephrine
peptide hormone
short chains of linked amino acid ex: oxytocin uterus contraction milk ejection
protein hormone
long chains of linked amino acids ex: growth hormone
steroid hormone
derived from the lipid cholesterol ex: testosterone and progesterone hydrophobic
