Heart 1
What type of blood is found on the left and right side of the heart respectively? Why are they different and where does the blood come from?
The right side of the heart contains deoxygenated blood, which is sent to the lungs for oxygenation through the pulmonary arteries.
The left side of the heart contains oxygenated blood, which is sent throughout the body through the systemic circuit.
They are different because of their location in the circulation route. The right side of the heart receives deoxygenated blood from the rest of the body, and the left side receives oxygenated blood from the lungs.
Explain the anatomy of the heart. Mention the location in the chest, the layers of the heart, the type of muscle cell, and the chambers and valves in order from the right atrium.
The heart is located in the thoracic cavity (mediastinum is the proper word), slightly to the left of the midline, and positioned behind the sternum between the lungs.
The layers of the heart include the pericardium, the outermost covering made of two layers (parietal and visceral layers making the serous sac), the myocardium, a thick muscular layer composed of cardiac muscle cells, and the endocardium, inner lining of the heart layer composed of endothelial tissue.
The chambers and valves of the heart in order:
Right atrium --> tricuspid valve --> right ventricle --> pulmonary valve --> lungs -->left atrium --> mitral valve --> left ventricle --> aortic valve --> rest of the body
Explain the pathway of air. What part of the pathway makes the conducting and respiratory zones?
Nasal cavity --> pharynx --> larynx --> trachea --> bronchi --> bronchioles --> respiratory bronchioles --> alveolar ducts --> alveoli
Conducting zone is from the nasal cavity to the terminal bronchioles
Respiratory zone is from the respiratory bronchioles to the alveoli
What are the three segments of the pharynx and the function of the larynx? What are the cartilage of the larynx? What is the function of the epiglottis?
Three segments of the pharynx are the nasopharynx, oropharynx, and laryngopharynx.
The larynx is responsible for air pathway from the pharynx to the trachea, and sound production (vocal folds) and contains the thyroid cartilage, cricoid cartilage, epiglottis (responsible for preventing food and liquid from entering the lungs), arytenoid cartilages, corniculate cartilages, and cuniform cartilages
What is the function of the skin?
Protection- acts as a barrier against physical injury, pathogens, and UV radiation
Regulation and excretion- maintains body temperature through sweat production and blood vessel dilation/constriction, and removes waste products like salts and urea
Sensation- contains nerve endings that detect touch, pressure, pain, and temperature
Vit D synthesis- produces vitamin D when exposed for sunlight
Waterproofing- prevents excessive water loss and maintains hydration through lipid barrier
What are the different valves of the heart and what sections do they separate for the heart?
Atrioventricular valves separate the atriums and ventricles
Tricuspid valve- from the right atrium to the right ventricle
Mitral valve (Bicuspid valve)- from the left atrium to the left ventricle
Semilunar valves separate the ventricles into the major arteries
Pulmonary valve- from the right ventricle to the pulmonary artery (further sent to the lungs)
Aortic valve- from the left ventricle to the aorta (further sent to the rest of the body)
**MNEMONIC**
to remember the tricuspid and bicuspid valve order you always Try before you Buy (tricuspid first then bicuspid)
pulmonary valve sends blood to the lungs (pulmo-)
aortic valve sends to the aorta
What does each wave represent in an EKG? **BONUS** give the times for every section.
P wave- atrial depolarization (contraction) 80-100ms
PR interval- electrical impulse traveling from atria to ventricles 120-200,s
QRS complex- ventricular depolarization (contraction) </= 120ms
ST segment- early ventricular repolarization 80-120ms
T wave- ventricular repolarization (relaxation) 160ms
What are the main events in the respiratory system?
External respiration- gas exchange in the lungs (air to blood)
Gas transport- oxygen and CO2 transported via blood
Internal respiration- gas exchange at tissues (blood to cells)
cellular respiration- oxygen is used in energy production
The respiratory center is located in the medulla oblongata and pons adjusts breathing in response to CO2, O2, pH levels, and external inputs for maintaining homeostasis
What are the layers of the skin?
Epidermis- outer layer made of stratified squamous epithelial cell, provides protection of environmental damages (from outermost to innermost is divided by stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale)
**MNEMONIC**
for the layers of the epidermis you can think of "Come Let's Get Sun Burnt" for each layer
Dermis- middle layer made of connective tissue, contains collagen, elastin, blood vessels, sweat and sebaceous glands, and hair follicles and nerve endings (papillary layer, thin upper later with capillaries and sensory neurons, reticular layer, thicker, lower layer with dense connective tissues)
Hypodermis (subcutaneous)- deepest layer, made of adipose and connective tissue, provides insulation, energy storage, and allows for anchoring of the skin to underlying structures
What is the order of the conduction pathway of the heart? What is considered the pacemaker of the heart? What happens when that pacemaker is damaged/cannot function?
Sinoatrial node --> atrioventricular node --> bundle of His --> right and left bundle branches --> purkinje fibers
the SA node is considered the pacemaker of the heart as it starts each impule. When damaged or nonfunctional, the AV node can take over to accommodate for the absence of the SA node, can lead to slower heart rate and irregular rhythm
Give the flow of blood through the pulmonary and systemic circuit starting from the inferior/superior vena cava (MENTION THE VESSEL NAMES)
What is the tidal volume for an average person in liters? What factors contribute to inhalation/exhalation?
Tidal volume is the amount of air normally inhaled/exhaled during restful breathing (0.5L)
Factors for inspiration: diaphragm contraction, lung compliance, and atmospheric pressure
Factors for expiration: diaphragm relaxation, elastic recoil of lungs, alveolar surface tension, increased intrapulmonary pressure, and obstructions
How does gas exchange work?
Gas exchange works via diffusion, driven by concentration gradients, and allows oxygen to move from the alveoli to the blood, and for CO2 to move from the blood to the alveoli
What is the function of keratin?
Keratin acts as a protective layer of the skin and makes the skin water-resistant, provide structural support for the skin hair and nails, and provides wound healing abilities.
Where is EPO produced? How is EPO production changed at higher altitudes? What are the differences in polycythemia and anemia?
EPO is produced mainly in the kidneys to stimulate RBC production in response to low oxygen levels. At higher altitudes, there is less oxygen, so the body accommodates by trying to produce more RBCs to bind with more O2.
Polycythemia occurs when there is an excess of RBCs, leading to thick blood and clotting. Anemia is a deficiency of RBCs/hemoglobin, leading to reduced O2 delivery.
What is the cardiac output (CO) formula and some factors that can affect it?
CO=SV x HR
Factors that can affect it are preload, afterload, contractility, ANS activity, hormonal influence, exercise, blood volume, and venous return
What is the function of the pleura? What is the difference between pleural effusion and pneumothorax?
The pleura is a double layered membrane surrounding the lungs and acts as protection, lubrication of the lung expansion, and pressure regulation (negative pressure)
Pleural effusion is the accumulation of excess fluid in the pleural cavity and can cause restriction of lung expansion. Pneumothorax is the presence of air/gas in the pleural space, causing the lungs to collapse due to disruption of negative pressure.
What are the differences between restrictive and obstructive lung disorders, and what are the common diseases for both?
Restrictive lung disorders cause a reduction in lung volume (TLC and FVC) making it difficult to expand the lungs fully (ex. pulmonary fibrosis, asbestosis)
Obstructive lung disorders cause blockages, and narrowing of the airways, making it difficult to exhale air efficiently (ex. COPD, asthma, cystic fibrosis)
What is the function of melanin and how does melanoma occur?
How does pressure change from the aorta to the veins? How does that affect blood flow?
As the blood travels from the aorta to the veins, pressure decreases significantly, going from 120mmHg to 5-10mmHg. This pressure gradient allows for blood to propel through the circulatory system, while valves, muscles, and respiratory pumps assist the veins in returning that blood to the heart
Where are the baro and chemoreceptors located and how to they respond with pressure, pH, and chemical changes?
Baroreceptors, in the carotid sinus and aortic arch, detect changes in blood pressure (increased pressure activates parasympathetic response and decreased pressure activates sympathetic response)
Chemoreceptors are located in carotid bodies, aortic bodies, and medulla, and respond to changes in CO2 O2 and pH changes (peripheral chemoreceptors respond to low O2 and high CO2 or low pH by increasing respiration, central chemoreceptors respond to high CO2 and low pH signaling for increased respiration
What different types of epithelium are found in the respiratory tract, and what is the difference between type I and type II alveoli? Which produces surfactant?
Pseudostratified ciliated columnar epithelium in the upper respiratory tract, and simple columnar/simple cuboidal epithelium in smaller bronchioles.
Type I alveoli are involved in gas exchange, and type II produce surfactant to reduce surface tension and regenerate damaged cells
What are the normal values of respiration in mL? Mention tidal volume, inspiratory reserve volume, expiratory reserve volume, residual volume, total lung capacity, vital capacity, inspiratory capacity, and functional residual capacity.
TV- 500mL
IRV- 3000mL
ERV- 1200mL
RV- 1200mL
TLC- 6000mL
VC- 4800mL
IC- 3500mL
FRC- 2400mL
What are the classifications of burns and what layers of the skin does each target?
First-degree burns- superficial burns that affect the epidermis
Second-degree burns- partial thickness burns that affect the epidermis and part of the dermis, causes blisters, and potential scarring
Third-degree burns- full thickness burns, affects the epidermis, dermis, and some subcutaneous tissue, causes a charred, white appearance of the skin; no pain on the burn site due to nerve endings being destroyed
Fourth-degree burns- affects the epidermis, dermis, subcutaneous tissue, and underlying structures like muscles tendons and bones; often blackened or charred, no pain or sensation due to nerve endings being destroyed