CORRECT ANSWERS 2026 LATEST
UPDATE
What are the major differences between the cardiac action potential and the skeletal
action potential? What causes these differences why is it important for how the heart
functions? - Answer- Skeletal muscle has action potentials that are much quicker (2ms)
opposed to cardiac muscles. (200-500ms)
Cardiac muscle does not need to be stimulated by a motor neuron to trigger new action
potentials due to the junction gaps at intercalated disks
Cardiac muscle has a depolarization phase followed by a plateau phase. A rapid
repolarization takes place afterward. The continuous movement of calcium ions inwards
following depolarization causes K+ diffusion to slow leading to the plateau phase. Once
voltage gated calcium ion channels close, repolarization is rapid
The relaxation brought on by the plateau phase prevents cardiac muscle from
developing tetanic contractions leading to the overall importance in the difference in
functioning between cardiac and skeletal muscle.
What is the role of the Sinoatrial (SA) node in the heart? Describe the conduction
system of the heart. How does this conduction system facilitate the smooth coordinated
contraction of the heart that is important for it to function as a pump? - Answer- The
sinoatrial node is located towards the top of the right atrium and is responsible for
commencing cardiac muscle contractions and controlling the heart rate through action
potentials
The SA node allows the charge to pass through into the atrioventricular node in the
lower part of the right atrium. This causes the atria to contract. The charge is then sent
from the AV node to the atrioventricular bundle; Because the atria have more calcium
ion channels, they contract slower. This slowed contraction causes the atria to contract
before the charge can be passed through the atrioventricular bundle. The bundle then
divides into the left and right bundle branches which connect to purkinje fibers which
connect to the ventricles. Once the ventricles relax the SA node will send out another
action potential initiating the next rhythmic pumping movement. If the SA node was
unable to function another node such as the AV node can become the new pacemaker.
After six months of training an individual has a lower resting heart rate than she did prior
to training when running at the same speed. Her cardiac output, however, is essentially
,the same. What do you think accounts for this? Define cardiac output and its
components in your answer. Do you think her resting HR is different after training? -
Answer- Cardiac output is defined as stroke volume (mL/beat) multiplied by heart rate
(beats/min) and refers to the amount of blood exiting the ventricles per minute.
An athlete who has been training will tend to develop a higher venous return leading to
a higher preload and a more forceful contraction. This means that an athlete's heart will
be increased in size and have a typically higher stroke volume. A non-athlete will have a
lower stroke volume but a higher heart rate to compensate. The reason why an athlete
would have a similar cardiac output but a lower heart rate than a non-athlete is because
the athlete would have developed a higher stroke volume to compensate for the
increased size of the heart.
After training the resting heart rate would be elevated due to the increased need for
blood flow throughout the body
Describe the formation and movement of lymph fluid. - Answer- Lymph refers to the
additional 3 liters of fluid that is put into interstitial spaces rather than back into the
blood.
Lymph is created through fluids that are absorbed into the lymphatic capillaries from the
tissues and moves through lymphatic vessels. Within the vessels, valves exist to
prevent back-flow. As lymph passes through vessels they encounter lymph nodes which
act as a filter in the presence of infections. Once lymph enters the thoracic duct it can
re-enter the blood. Lymph moves due to muscular contractions from skeletal and
breathing.
Discuss the differences between innate (non-specific) and adaptive (specific) immunity.
List the white blood cells that are involved in each type of response. - Answer- Innate
immunity
The body is capable to destroy certain pathogens but the response to the pathogen is
the same upon each exposure. This is the same each time because it lack the
specificity and memory of adaptive response. Innate involves the following WBC's
phagocytes, neutrophils, macrophages, basophils, eosinophils and natural killer cells
Adaptive immunity
Adaptive immunity can react to the presence of antigen however, upon a second
exposure the response is improved due to it's specificity and memory within it's
immunity properties. This involves the following WBC's: lymphocytes being B and T
cells.
Describe the steps of the local inflammatory response to tissue damage caused by
bacterial infection including the roles of the different chemical mediators and white blood
cells. - Answer- Bacteria enters tissue causing damage and insinuating an inflammatory
response
, Damage causes the release of chemical mediators
Mediators include histamine, prostaglandins, leukotrines, complement and kinins (all
increase inflammation, vascular permeability and commence phagocytosis
Increasing vascular permeability allows for fibrinogen to enter the tissue and converts to
fibrin which isolates the infected tissue
Complements cause chemotaxis where phagocytes are attracted to the site of injury.
The attraction of WBC's and phagocytes continues until the bacteria is destroyed; then
the tissue may heal
If the bacteria is not destroyed additional chemical mediators are released furthering the
inflammatory response until the bacteria is destroyed
Briefly describe the functions of the digestive system - Answer- Ingestion - Consumption
through the mouth in solid or liquid form
Digestion -
Breakdown of large organic molecules into smaller absorbable molecules
Absorption -
Movement of molecules out of the digestive tract and into the blood or lymphatic system
Elimination -
Removal of undigested material through feces
Describe the structure and general functional roles of the four tunics (layers) of the
digestive tract and briefly highlight the differences between the different organs related
to their specialized functions - Answer- The four tunics include:
- Muscosa
Consists of the muscosa epithelium, lamina propria, muscularis mucosae
- Submucosa
Thick layer of connective tissue that contains nerves, vessels and glands
- Muscularis
Inner layer of smooth muscle and outer layer of longitudinal smooth muscle
- Serosa (Adventitia)
Smooth epethelial layer with connective tissue
Name and describe the three phases of deglutition (swallowing). Include the relevant
anatomy involved in each phase - Answer- Divided into: