Science Flashcards
What are the three body planes?
Sagittal/lateral
Coronal/frontal
Axial/transverse
What is the difference between medial and lateral?
Medial- nearer to the midline of the body
Lateral- further away from body’s midline, at the sides
Ex. Thumb is lateral to the little finger
Ex. Little finger is medial to the thumb
What does proximal mean and what term of an atomic direction is the opposite?
Proximal- structures closer to the center of the body
Opposite: distal
Knee is distal to the hip
Hip is proximal to the knee
What does anterior, posterior,superior, and inferior mean?
Anterior- front
Posterior- behind
Superior- above (closer to the head)
Inferior- below (closer to the feet)
Ex. Ribs are anterior to the lungs
Ex. The nose is inferior to the eyes
What are the abdominal quadrants?
Stomach is divided into 4 quadrants to identify the position of the organs
What structures comprise of the respiratory system? And what is its primary function?
Nose, mouth, nasal cavity, sinuses, pharynx, larynx, trachea, bronchial tree, and lungs
Function: deliver oxygen to the cells of the body for cellular respiration and remove waste in the form of co2
What is the generalized structure of the lungs?
Spongy, porous organs that occupy the thoracic cavity
Pleura (serous membrane) lines the thoracic cavity and the surface of the lungs
The right lung (3 lobed) and the left lung (2 lobe) is separated by the mediastinum
The trachea forks into primary bronchi which enter the right and left lung at the hilum
What are the divisions of the passages to the lungs?
Trachea splits into two primary bronchi (one for each lung) which then split into secondary bronchi, tertiary bronchi, and bronchioles to form a bronchial tree
The terminal bronchioles divide into respiratory bronchioles which are in the presence of some alveoli
The respiratory bronchioles lead into alveolar ducts which terminate in alveolar sacs
What is the general mechanism for breathing?
Inspiration: the diaphragm and intercostals contract= thoracic cavity increases= rib cage and sternum elevate and expand outward
Increase in volume= decrease in intrapleural pressure = air enters lungs
Expiration: volume of thoracic cavity decreases= intrapleural pressure increases = air leaves lungs
How is the circulatory system involved in thermoregulation?
Thermoreceptors detect change in temp and send impulses to hypothalamus which then send impulses to the effectors ( smooth muscles that surround cutaneous arterioles)
Body temp warm= smooth muscle relaxes and the arterioles dilate to allow more blood to flow through the capillary beds near surface of the skin = heat becomes lost in the surroundings
Body temp cool= opposite ^
What are the three layers of the heart?
Epicardium (outer layer) - protects the heart and secretes lubricating serous fluid
Muscular myocardium (middle layer)- contracts to pump blood
Endocardium (innermost layer) - lines the chambers and valves
What are the different valves of the heart and their respective functions?
Tricuspid valve (right AV valve) - prevent back flow into the atrium when ventricle contracts
Pulmonary semilunar valve - prevents return of blood into right ventricle
Bicuspid valve (left AV valve, mitral valve)- prevents blood from entering left atrium when ventricle contracts
Aortic semilunar valve- stops back flow of blood into the left ventricle as it leaves aorta
What is blood pressure, and what do the two numbers mean?
The force per unit area that is exerted by the blood on the walls of the vessels.
Systolic pressure (upper number)- maximum pressure when the ventricles contract, forcing blood into the aorta and pulmonary trunk
Diastolic pressure: ventricles relax and the Bp is at its lowest
What are the primary differences between the systemic and pulmonary circulation?
Systemic circuit is much longer and the bp is higher than pulmonary circuit
Systemic circuit: blood in arteries carries more o2 than blood in the veins
- when o2 is low, vessels dilate to promote blood flow to tissues that need it
Pulmonary circuit: blood in veins carries more o2 than arteries
- when o2 is low- it triggers vasoconstriction (narrow blood vessels), which redirects blood to better ventilated parts of the lung
What are the components of the ecg, and what cardiac events do they correspond?
P wave represents depolarization of the atria on an ECG. Followed by QRS interval, which represents depolarization of the ventricle. Next follow the ST segment and T wave, corresponding to depolarization of the ventricle. A small U wave may follow the T wave to represents further depolarization of ventricle
