A&P Final Flashcards
What is the definition of homeostasis?
The maintenance of a stable internal environment
What are the components of a feedback loop?
Receptor
Control center
Effector
Describe the afferent pathway.
Input flows from the receptor to the control center
Describe the efferent pathway.
Output flows from the control center to the effector
What does a positive feedback loop do?
The variable change enhances or aggravates initial stimulus.
What does a negative feedback loop do?
The variable change is opposite of the initial stimulus.
What is an example of a positive feedback loop?
Regulation of blood clotting
What is an example of a negative feedback loop?
Regulation of blood volume
Regulation of body temperature
Describe medial.
Toward the midline of the body
Describe lateral.
Away from the midline of the body
Describe proximal.
Closer to the point of attachment
Describe distal.
Further from the point of attachment
Define flexion.
A decrease in the joint angle
Define extension.
An increase in the joint angle
Define dorsal flexion (dorsiflexion).
A decreased angle of the ankle joint.
What is an example of dorsiflexion?
Pull toes up
Define plantar flexion.
An increased angle of the ankle joint
What is the example of plantar flexion?
Pointing toes
Define abduction.
A lateral movement away from midline
Define adduction
A lateral movement towards the midline
What is the origin of a muscle?
Where a muscle attaches to the immovable or less movable bone.
What is the insertion of a muscle?
Where a muscle attaches to the movable bone.
What is an example of an isotonic contraction?
A bicep curl (Pulling up- concentric; lowering bar- eccentric)
What is an example of an isometric contraction?
Holding a plank position
What are the types of an isotonic (dynamic) contraction?
Concentric
Eccentric
Define an isotonic (dynamic) contraction.
The muscle develops tension as it changes length
What is a concentric contraction?
The muscle shortens as it develops tension
What is an eccentric contraction?
The muscle lengthens as it develops tension
Define an isometric (static) contraction.
The muscle develops tension, but does not change length
Define an isokenetic contraction.
An isotonic contraction at a constant velocity
What are the 5 roles of muscles?
Agonist Antagonist Stabilizer Synergist Neutralizer
What is an agonist?
The prime mover responsible for joint motion during contraction.
What is an antagonist?
A muscle located opposite the agonist and has the opposite action.
What is a stabilizer?
A muscle that surrounds the joint or body part and serves as a fixator or stabilizer during a contraction
What is a synergist?
A muscle that assists the agonist, but is not a prime mover.
What is a neutralizer?
A muscle that counteracts the action of the other muscles to prevent undesired movements
Origin~Base of skull, occipital protuberance, posterior ligaments of neck, spinous processes of cervical (C7) and all thoracic vertebrae (T1-12)
Insertion~Posterior aspect of lateral third clavicle, medial border of acromion process & upper border of scapular spine, triangular space at base of scapular spine
Trapezius
Origin~Transverse processes of upper cervical vertebrae (C1-4)
Insertion~ Medial border of the scapula above the spine
Levator Sacpulae
Origin~ Anterior surfaces of the third to the fifth rib
Insertion~ Coracoid process of the scapula
Pectoralis minor
Origin~ Medial half of anterior surface of clavicle, anterior surface of costal cartilages of first six ribs, adjoining portion of sternum
Insertion~ Flat tendon 2-3 inches wide to outer lip of intubercular groove of humerus
Pectoralis major
Origin~ Anterior lateral third of the clavicle, lateral of the acromion, and the inferior edge of the spine of the scapula
Insertion~ Deltoid tuberosity on the lateral humerus
Deltoid
Origin~ Posterior crest of the ilium, back of the sacrum and spinous processes of lumbar and lower six thoracic vertabrae, slips form the lower three ribs
Insertion~ Medial side of intertubercular groove of the humerus
Latissimus dorsi
What are the three joints that make up the elbow?
Radioulnar
Radiohumeral
Ulnohumeral
What type of joint is the radioulnar joint?
Pivot- allows for pronation and supination
What type of joint is the radiohumeral joint?
Hinge- allows for flexion and extension of the elbow only
What type of joint is the ulnohumeral joint?
Hinge- allows for flexion and extension of the elbow only
What bones make up the elbow joint?
Humerus
Ulna
Radius
Origins~Superglenoid tubercle ~Coracoid process
Insertion~Radial tuberosity
Biceps brachii
Origin~Distal two-thirds of the lateral condyloid (supracondylar) ridge of the humerus
Insertion~Lateral surface of the distal end of the radius at styloid process
Brachioradialis
Origin~Infraglenoid tubercle of scapula~Upper half of posterior surface of the humerus~Distal two-thirds of posterior surface of the humerus
Insertion~Olecranon process of the ulna
Triceps brachii
Origin~Lateral epicondyle of the humerus~Neighboring posterior part of the ulna
Insertion ~Lateral surface of proximal radius just below the head
Supinator
Origin~Lateral epicondyle of the humerus
Insertion~Four tendons to bases of middle and distal phalanges of four fingers (dorsal surface)
Extensor digitorum
What are the three Erector spinae muscles?
Iliocostalis
Longissimus
Spinalis
Origin~Superior sacrum
Insertion~Posterior ribs and cervical transverse processes
Iliocostalis
Origin~Superior sacrum
Insertion~Cervical and thoracic transverse processes and the mastoid process
Longissimus
Origin~Upper lumbar and lower thoracic spinous processes
Insertion~Cervical and thoracic spinous processes and the occipital bone
Spinalis
Origin~Crest of pubis
Insertion~Cartilage of fifth, sixth, and seventh ribs~Xiphoid process
Rectus abdominis
Describe the curvature of the spine.
~Cervical (C1-C7) and Lumbar (L1-L5) curves are concave posteriorly
~Thoracic spine (T1-T12) is convex posteriorly
~The sacral curve is efficient in absorbing blows and shocks
What are the main differences in cervical, thoracic, and lumbar vertebrae?
The cervical vertebrae have a larger vertebral foramen and a larger body. The thoracic vertebrae have smaller vertebral foramen, larger bodies, and larger transverse processes. The lumbar vertebrae have small vertebral foramen, large bodies, and “stubby” spins and transverse processes.
What are the four muscles that make up the Quadriceps muscle group?
Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius
What is an important fact about the Quadriceps?
It should be about 25-30% stronger than the hamstring muscles.
Origin~Intertrochanteric line, anterior and inferior borders of the greater trochanter, upper half of the linea aspera and the entire lateral intermuscular septum
Insertion~Lateral border of patella, patellar tendon to tibial tuberosity
Vastus lateralis
Origin~Upper two-thirds of anterior surface of femur
Insertion~Upper border of patella and the patellar tendon of tibial tuberosity
Vastus intermedius
Origin~Whole length of linea aspera and medial condyloid ridge
Insertion~Medial half of the upper border of the patella and patellar tendon to the tibial tuberosity
Vastus medialis
What muscles make up the Hamstrings?
Biceps femoris
Semimembranosus
Semitendinosus
What is an important function of the hamstrings?
Their flexibility
Origin~Posterior surfaces of two condyles of the femur
Insertion~Posterior surface of calcaneus
Gastrocnemius
Origin~Proximal two-thirds of posterior surfaces of tibia and fibula
Insertion~Posterior surface of calcaneus
Soleus
Origin~Anterior superior iliac spine and notch just below the spine of ilium
Insertion~Anterior medial condyle of tibia
Sartorius
Origin~Anterior inferior iliac spine~Groove (posterior) above the acetabulum
Insertion~Superior aspect of the patella and patellar tendon to the tibial tuberosity
Rectus femoris
Origin~Posterior one-fourth of the crest of ilium, posterior surface of the sacrum and coccyx near the ilium, and fascia of the lumbar area
Insertion~Oblique ridge on lateral surface of the greater trochanter and iliotibial band of fascia latae
Gluteus maximus
What muscle provides important lateral stability to the knee joint?
Biceps femoris
Origin~Ischial tuberosity~Lower half of linea aspera, lateral condyloid ridge
Insertion~Lateral condyle of tibia, head of fibula
Biceps femoris
Origin~Anterior medial edge of descending ramus or pubis
Insertion~Anterior medial surface of tibia below condyle
Gracilis
What six bones make up the pelvic girdle?
Ilium Ischium Pubis Sacrum Coccyx Femur
What are the four neuroglia of the CNS?
Astrocytes
Microglia
Ependymal cells
Oligodendrocytes
What is the function of oligodendrocytes?
Cytoplasmic extensions become insulating myelin sheaths
What is the function of the ependymal cells in the CNS?
They cushion the brain and spinal tissue by circulating cerebrospinal fluid with their cilia
What is the function of the microglia in the CNS?
They are the ‘immune cells’ of the CNS; they sense neuronal health and degrade harmful substances
What are the functions of the astrocytes in the CNS?
~They provide anchoring support for neurons and insure nutrient delivery
~They direct neuronal growth
~They take up potassium ions and used neurotransmitters (importance of glucose)
What are the two types of neuroglia of the PNS?
Satellite cells
Schwann cells
What are the functions of the satellite cells?
~They surround neuronal bodies
~They provide similar functions as the astrocyes in the CNS
What are the functions of the schwann cells in the PNS?
~They surround larger PNS fibers with myelin
~They help with peripheral nerve fiber regeneration
~They are similar in function to the oligodendrocytes in the CNS
What are the three functional components of a neuron?
Receptive region
Conducting component
Secretory component
What makes up the receptive region of the neuron?
Dendrites and cell body
What makes up the conducting component of a neuron?
The axon
What makes up the secretory component of a neuron?
The axon terminals
What is the function of the receptive region or a neuron?
It receives impulses from a stimulus
What is the function of the conducting region of a neuron?
It generates/transmits an action potential
What is the function of the secretory region of a neuron?
It releases neurotransmitters
What is Ohm’s law?
Current (I) equals voltage (V) divided by resistance (R)
I = V/R
What is voltage of Ohm’s law in humans?
Ionic difference (membrane potential)
What is current of Ohm’s law in humans?
The flow of ions in and out of the cells
What is resistance of Ohm’s law in humans?
The plasma membrane
What defines electrochemical gradients?
~Movements of opposite charges
~Movement along a concentration gradient (high to low)
What is the most common resting membrane potential?
-70 mV
Is the outside or the inside of a cell more positive?
Outside
Is the outside or inside of a cell more negative?
Inside
At rest, what is the intercellular concentration of ions?
Higher K+ and lower Na+
At rest, what is the extracellular concentration of ions?
Higher Na+ and lower K+
What are the two mechanisms used to stabilize the resting membrane potential of a neuron?
~Permeability of plasma membrane (more positive outside than inside)
~Sodium potassium pump (actively stabilizes the membrane potential)
Describe the six steps used by the sodium-potassium pump to stabilize the membrane potential.
1-Cytoplasmic Na+ binds to the pump protein which stimulates phosphorylation by ATP
2-Phosphorylation causes the protein to change its shape
3-The shape change expels Na+ to the outside of the cell, and extracellular K+ binds to the protein
4-The binding of K+ triggers the release of the phosphate group
5-The loss of the phosphate restores the original conformation of the pump protein
6-The K+ is release and Na+ sites are ready to bind Na+ again; the cycle repeats
What happens during the depolarization phase of an action potential in a muscle (except for cardiac muscle)?
Na+ flows into the cell
What causes the positive “voltage spike” of an action potential?
Depolarization of the membrane (Na+ influx)
What happens during the repolarization phase of an action potential?
Na+ channels start to close; K+ channels open and K+ flows out of the cell
What happens during the undershoot (hyperpolarization) phase of an action potential?
Na+ channels are closed, but K+ channels are sill open
What is the threshold potential?
It is the membrane potential that must be reached for an action potential to fire
What are some important facts about action potentials that we need to know?
~Each action potential is identical to the one that triggered it
~Repolarization “chases” depolarization
~Local current flow depolarizes adjacent areas of the plasma membrane
~Action potentials follow the all or none phenomenon
What is the absolute refractory period?
The period when no other stimulus will generate an action potential (Na+ channels are still open)
What is the relative refractory period?
The period that follows the absolute refractory period when the neuron can receive another stimulus given the stimulus is strong enough
What is an IPSP?
Local hyperpolarization of the postsynaptic membrane pushing the membrane away from threshold
What is an EPSP?
Local depolarization of the postsynaptice membrane pushing the membrane towards threshold ultimately leading to a graded potential
Define temporal summation.
When there is multiple stimuli in one place; one neuron transmits a stimuli over and over
Define spatial summation.
When more than one neuron is acting on anther; two or more axons are attached to the same neuron
What is important to note about IPSP, EPSP, and the summation affect?
One IPSP will ‘cancel out’ one EPSP of the same magnitude
What are some differences between graded and action potentials?
~Graded potentials are local and will only activate a portion of the plasma membrane at one time. Action potentials depolarize the entire plasma membrane
~Graded potentials uses the summation affect, whereas action potentials have the all or none phenomenon.
~Action potentials have the same magnitude as the potential that activated it, but graded potentials lose strength as they move across the plasma membrane
~The summation of graded potentials can lead to an action potential if they cause the entire membrane to reach threshold
Where does the action potential start and where does it go?
The AP starts at the axon hillock and moves down the axon to the axon terminals
What is saltatory conduction?
It is the propagation of action potentials along myelinated axons from one node of Ranvier to the next, increasing the conduction velocity of action potentials.
What would happen if a drug blocks calcium channels of a membrane?
The drug would bind to the voltage gated channels of the presynaptic neuron, blocking calcium from entering the neuron. This would inhibit the neuron from releasing neurotransmitters into the synaptic cleft.
What are the main differences between compact and spongy bone?
~Compact bone is very hard and has few gaps; spongy bone is riddled with holes, giving it a ‘spongy’ appearance
~Compact bone is found on the outside of the bone; spongy bone is found on the inside of the bone and is covered by compact bone
~Compact bone contains yellow bone marrow; spongy bone contains red bone marrow
Where is calcium stored and released in skeletal muscle?
Sarcoplasmic reticulum
What happens when ATP binds to myosin?
When new ATP attached to the myosin head, the cross bridge detaches. Then the ATP is split into ADP and a phosphate group; this causes the myosin head to “cock back”
What are the sequence of events that occur in exicitation-contraction coupling in skeletal muscle?
- A generated action potential is propagated along the sarcolemma and down the T tubules
- The action potential triggers calcium release from the terminal cisternae of the sarcoplasmic reticulum
- Calcium ions bind to troponin, changing its shape which removes its blocking action of tropomyosin; actin active sites are exposed
- Contraction occurs; myosin cross bridges alternately attach to actin and detach, pulling the actin filaments toward the center of the sarcomere; release of energy by ATP hydrolysis powers the cycling process
- Removal of Ca2+ by active transport into the sarcoplasmic reticulum after the action potential ends
- Tropomuosin blockage is restored, blocking actin active sites; contraction ends and muscle fiber relaxes
How does resistance training affect fiber size, neural recruitment, mitochondrial volume and capillary density?
Resistance training reduces mitochondrial volume and capillary density, but increases fiber size and glycolotic enzymes and myosin ATPase. Converts Type 2x fibers into type 2a
Where do you find myosin ATPase?
Myosin cross-bridges
Where does calcium go during muscle relaxation and how does it get there?
Calcium is put back into the sarcoplasmic reticulum through active transport
What are the three sites that ATP is compartmentalized in the muscle?
- Contractile elements
- Sarcolemma
- Sarcoplasmic reticulum
What are the two primary contractile proteins?
Myosin and Actin
What does binding of Ach to the sarcolemma of skeletal muscle cause?
Depolarization of the membrane (Na+ channels open), leads to action potential and then muscle contraction
What factors promote calcium accumulation in bone?
~Increased calcitonin
~Adequate dietary Ca+
~Mechanical stress (gravity and exercise)
~Adequate blood estrogen in females
What are the advantages and disadvantages of the immediate (creatine phosphate) energy system?
Advantages: Fast response, no toxic waste products, stores replenished rapidly (ab 2 mins), all reactions occur in the cell
Disadvantages: Lacks capacity- it can only be used for activities lasting about 10-15 seconds or less
List six features of ATP
- It cannot be absorbed during digestion
- It is not stored or released by any organ
- The level in the blood is very low and cannot penetrate cell membranes
- It is not stored in great quantities in the muscle
- It is compartmentalized in the cell: only a portion is available for muscle contraction
- It must be generated through metabolic pathways
What do you find in the proximal epiphysis of a long bone?
The proximal epiphysis of a long bone is made up of spongy bone surrounded by articular cartilage. There is a plate called the epiphyseal line that runs through the epiphysis that allows from vertical bone growth in children and adolescents. Once the epiphyseal plate hardens, bone growth ceases and the articular cartilage is replaced by compact bone.
What energy system produces lactic acid?
Glycolysis
What type of muscle fiber predominates in athletes with exceptionally good vertical leaps?
Type 2x; Fast glycolytic fibers They have a fast reaction time, used for short-term, intense or powerful movements
What has to happen in order for a muscle to relax?
Calcium must be pumped back into the sarcoplasmic reticulum
What accounts for the ‘sliding’ in the sliding filament theory?
Myosin heads attach to actin active sites and pull/push it towards the center of the sacromere. The actin slides past the myosin creating muscle tension and contraction
What energy system uses both free fatty acids and glucose for energy?
Oxidative phosphorylation
What is stroke volume?
The volume of blood pumped from one ventricle of the heart with each beat
What is ejection fraction?
The volumetric fraction of blood pumped out of the ventricle with each heart beat (SV/EDV)
What does acetylcholine do to the heart and why?
Acetylcholine is released by the parasympathetic nervous system to maintain or decrease heart rate through hyperpolarization.
Calculate cardiac output given heart rate and stroke volume
Cardiac output is the volume of blood being pumped by the heart in one minute (HR x SV)
Calculate pulse pressure
Pulse pressure is systolic pressure minus diastolic pressure. (SAP-DAP)
Calculate mean arterial pressure
Mean arterial pressure is diastolic pressure plus pulse pressure divided by three (DAP + PP/3)
What causes stroke volume to increase during exercise?
The sympathetic nervous system; epinephrine and norepinephrine
What does sympathetic activation do to heart rate, contractility, and preload during exercise?
Sympathetic activation releases norepinephrine which increases heart rate and causes cAMP activation of protein kinase phosphorylates; this activation promotes calcium entry by slowing calcium channels, promotes calcium release in the SR, and increases the rate of cross-bridge cycling in myosin fibrils. All of these increase contractility and stroke volume. Sympathetic activity also increases venous return, therefore increases preload.
What are arterial baroreceptors and what do they do?
Arterial baroreceptors are receptors located in various arteries that respond to stretching and relaxing of the arterial wall. An increase of barorecptor firing indicates an increase of blood pressure which causes an increase in parasympathetic activity; a decrease of barorecptors firing indicates a drop in blood pressure which triggers the sympathetic nervous system
Where does oxygenated blood go when it leaves the pulmonary circulation?
Oxygenated blood goes through the pulmonary veins into the left atrium
Where does deoxygenated blood go when it leaves the tissues?
Deoxygenated blood leaves the tissue through capillaries, into venules, then veins. Then into the superior or inferior vena cava and goes into the right atrium.
What are papillary muscles?
Muscles within the heart that hold the bicuspid and tricuspid valves closed during systole to prevent back flow into the atria
What are autorhythmic cells and what do they do?
They are pacemaker cells located in the electrical system of the heart. They control the electrical signal that causes the heart to beat. Without autorhythmic cells, the heart will cease to beat.
What is diastole?
The period of time when the heart refills with blood after systole
What is systole?
The contraction of the heart
What is the Frank-Starling law of the heart?
Stroke volume is controlled importantly by the degree of stretch imposed on the cardiac muscle (preload). Increase afterload can reduce stroke volume (hypertension).
What is afterload?
The load against which the heart contracts to eject blood
What do the various deflections on an EKG represent?
The P wave is atrial depolarization
The QRS complex is ventricular depolarization (contraction),
The T wave is ventricular repolarization
What returns to the heart from the inferior and superior vena cava?
Deoxygenated blood from the lower and upper body, respectfully
What is the most important factor influencing blood flow?
The most important factor influencing blood flow is resistance in the blood vessel; the most important factor influencing resistance is the radius of the opening of the blood vessel.
What is the purpose of the pulmonary semilunar valve?
The pulmonary semilunar valve prevents blood to flow back into the right ventricle after systole
Describe the anatomy of the conducting zone.a
The conducting zone is made up of the trachea, primary, secondary and tertiary bronchi, bronchioles, and terminal bronchioles.
What is the relationship between atmospheric, intrapleural, and intrapulmonary pressure?
Atmospheric pressure is about 760 mm Hg, intrapleural pressure is about 756 mm Hg (-4 mm Hg) so that the lungs are always open, and the intrapulmonary pressure is equal to the atmospheric pressure. The intrapulmonary pressure will decrease when the diaphragm moves downward for inspiration causing air to rush into the lunge (due to the now negative pressure). The opposite will happen during expiration
Discuss sources of airway resistance (diameter of the tube).
The most important factor influencing airway resistance is the diameter or the airway tube. If the diameter decreases, resistance increases; if diameter increases, resistance decreases.
Discuss how Fick’s law of diffusion facilitates oxygen and carbon dioxide transport at the tissues and the lungs
According to Fick’s law of diffusion, O2 and CO2 transport is dependent upon the surface area and thickness of the membrane in which the exchange will occurs. In the lungs, the alveoli are only one cell thick and have a very large surface area, therefore the rate of gas transfer is enhanced. Also, the diffusion coefficient determines how quickly gas exchange will occur; CO2 has a higher diffusion coefficient and will transfer more quickly than O2
Discuss the relationship between oxygen partial pressure and hemoglobin’s affinity for oxygen using the oxygen-hemoglobin dissociation curve
The higher the oxygen partial pressure within the tissue, the higher hemoglobin’s affinity for oxygen. Hemoglobin will never completely unload its oxygen, but if there is little oxygen in the tissue, it will unload most of its oxygen. During exercise, there is a lower oxygen partial pressure in the tissue, therefore hemoglobin’s affinity for oxygen is reduced. High temperature and pH decreases O2 pressure in the tissues as well
Discuss the three ways carbon dioxide is transported in the blood
CO2 can be transported within the plasma (7-10%), as a bicarbonate ion (70%), or it can bind to hemoglobin to form carbaminohemoglobin (20%) until it reaches an area for gas exchange.
Define tidal volume.
The amount of air inhaled or exhaled with each breath under resting conditions
Define inspiratory reserve volume (IRV).
The amount of air that can be forcefully inhaled after a normal tidal volume inhalation
Define expiratory reserve volume (ERV).
The amount of air that can be forcefully exhaled after a normal tidal volume exhalation
Define residual volume (RV).
The amount of air remaining in the lungs after a forced exhalation
Define Dalton’s law of partial pressure.
Total pressure exerted by a mixture of gases is the sum of the pressures exerted by each gas; the partial pressure of each gas is directly proportional to its percentage in the mixture
Define Henry’s law.
Mixed gases in contact with a liquid will dissolve in direct proportion to individual gas partial pressures; the amount of gas that will dissolve in a liquid also depends upon its solubility
Define Fick’s law.
The rate of gas transfer is proportional to the tissue areas, the diffusion coefficient of the gas, and the difference in the partial pressure, and is inversely proportional to thickness (Vg = A/T *D(P1-P2)
What is the difference between anatomical and alveolar dead space?
Anatomical dead space refers to the air that was inhaled, but not used in gas exchange; it is located in the airways (mouth and trachea). Alveolar dead space refers to the air that is in the alveoli, but doesn’t exchange gases; this happens in alveoli that have poor profusion, diseases lungs, or damaged lungs.
Describe the anatomy of the respiratory zone.
The respiratory zone is made up of the respiratory bronchioles, alveolar ducts, alveolar sacs, and the alveoli
What is the influence of sympathetic and parasympathetic neural activity on airway resistance?
The sympathetic activity will cause the airway to dilate, decreasing resistance. Parasympathetic activity will cause constriction of the airway, therefore increasing resistance.
