Cell Specialization
This type of pneumocyte produces surfactant to reduce surface tension in the alveoli.
What is a Type II pneumocyte?
These muscles contract to increase thoracic volume during inhalation.
What is the diaphragm and external intercostal muscles?
This vessel returns oxygenated blood from the lungs to the left atrium.
What is the pulmonary vein?
This tissue transports water and minerals from roots to leaves.
What is xylem?
These two proteins slide past each other to shorten the sarcomere.
What are actin and myosin?
This process allows oxygen and carbon dioxide to cross pneumocyte membranes by moving down their concentration gradients.
What is simple diffusion?
This chamber of the heart receives deoxygenated blood from the body before passing it to a ventricle.
What is the right atrium?
This valve closes when ventricular pressure rises above atrial pressure.
What is the atrioventricular valve?
This process in phloem tissue moves sugars from source cells into sieve tubes against their concentration gradient, using energy from ATP.
What is active transport?
This ion is released from the sarcoplasmic reticulum to initiate muscle contraction.
What is calcium?
This organelle is especially abundant in the midpiece of sperm to maximize ATP supply for movement.
What are mitochondria?
During inspiration, the thoracic pressure does this relative to atmospheric pressure to allow air in.
What is decrease?
This structure initiates the cardiac cycle through an electrical signal that causes atrial contraction.
What is the sinoatrial (SA) node?
As transpiration occurs, this happens to the pressure inside the xylem.
What is decrease?
During muscle contraction, this structure shortens as myosin heads pull actin filaments toward the center.
What is the sarcomere?
These junctions between cardiac muscle cells allow rapid transmission of electrical impulses between cells, ensuring coordinated contraction.
What are intercalated discs?
This term describes the volume of air moved in or out of the lungs in a single breath.
What is tidal volume?
During ventricular diastole, this type of valve closes to prevent backflow from the arteries into the ventricles.
What is a semilunar valve?
These cells support sieve tube elements by controlling loading and unloading of sugars and maintaining metabolic functions.
What are companion cells?
Calcium ions bind to this protein to uncover binding sites on actin and trigger muscle contraction.
What is troponin?
Explain the function of Type II pneumocytes and predict what would happen if they were damaged.
Type II cells reduce surface tension to prevent alveolar collapse; if Type II cells are damaged, alveoli collapse and gas exchange decreases.
If tidal volume is 0.6 L and ventilation rate is 20 breaths/min, this is the total volume of air inhaled in one minute.
What is 12L?
Explain why the pulmonary artery differs from typical arteries in terms of their function.
What is because it carries deoxygenated blood and delivers blood (from RV) to lungs for gas exchange instead of to body tissues?
If a plant’s phloem is damaged, predict the effect on growth in roots and developing fruits and explain why.
- Sugars and organic compounds cannot move from sources to sinks
- Reducing root growth and fruit development because energy and building blocks are unavailable
State where calcium ions are released in muscle cells, and predict the effect of a drug that blocks this release.
What is the sarcoplasmic reticulum; if calcium release is blocked, muscle contraction cannot occur