Exam 2 study guide

How does a hormone affect cells?

It connects to the cell hormone receptors.

What are cell receptors?

Protein molecules on the surface or inside a cell that act as specific binding sites for signaling molecules (ligands).

What controls most hormone concentrations?

The hypothalamus and the pituitary gland.

What is the effect of a steroid hormone binding to a receptor in a target cell?

It alters the expression of the cell.

What does upregulated mean in a cell?

A cell has increased its activity or production of specific molecules (like protein or RNA) in response to a stimulus.

What does downregulated mean in a cell?

A cell has decreased activity or production of a molecule due to a signal.

What are the actions and mechanisms of growth hormone?

It binds to target cells to stimulate a response, influence height, and help build bone and muscle.

What is the role of ADH?

Regulates water balance, blood pressure, and blood vessel constriction.

What does Triiodothyronine regulate?

The body's metabolic rate, meaning it controls how quickly the body uses energy from food.

What is the function of Parathyroid hormone?

Regulates blood calcium levels by stimulating the release of calcium from bones, promoting calcium reabsorption in the kidneys, and facilitating calcium absorption in the intestines through vitamin D activation.

What is the function of Adrenocorticotropic hormone (ACTH)?

Stimulates the adrenal cortex to release cortisol.

What does Melatonin help regulate?

Sleep-wake cycles and circadian rhythms.

What hormones are released by the Anterior pituitary gland?

Growth hormone, Prolactin, Thyroid-stimulating hormone, Adrenocorticotropic hormone, Follicle-stimulating hormone, Luteinizing hormone.

Which hormones are released by the Posterior pituitary gland?

Oxytocin and Antidiuretic hormone.

Where are the target cells for hypothalamic-releasing hormones located?

Anterior pituitary gland.

What is diabetes insipidus?

A rare hormonal disorder that causes excessive thirst and urination.

What are the actions of cortisol?

Regulates body response to stress, increases plasma protein, catabolism, muscle breakdown, free fatty acids, blood glucose, and SNS response; suppresses the immune and inflammatory system.

What are the actions of insulin?

Decreases glucose levels in the blood.

What does glucagon do?

Increases glucose levels in the blood.

What is the cause of Type 1 diabetes mellitus?

Genetic and environmental factors; an autoimmune reaction.

What is the cause of Type 2 diabetes mellitus?

A combination of genetics and environmental factors, including being overweight and not exercising; caused by insulin resistance.

What are some effects of Diabetes mellitus?

Weight loss, excessive thirst or urination, blurred vision, dry skin, numbness or tingling in hands or feet, fatigue.

Describe an RBC.

Responsible for carrying oxygen from the lungs to the rest of the body.

How are RBC levels regulated?

By the hormone erythropoietin.

What are the effects of Hypoxemia?

Shortness of breath, rapid breathing, fast heart rate, coughing or wheezing, confusion, bluish skin color, headache.

What is a hematocrit?

A blood test that measures the percentage of red blood cells in your blood.

What is a normal hematocrit?

For adult males is typically between 41% and 50%, while for adult females it is between 36% and 44%.

How long do RBCs live?

120 days.

How are RBCs broken down?

By macrophages in the spleen and liver.

What is the normal pH of blood?

7.35 to 7.45.

What is the structure of hemoglobin?

Four protein subunits arranged in a tetrahedral structure, with each subunit containing a polypeptide chain and heme group which binds oxygen.

What is the underlying cause of sickle cell disease?

A mutation in the HBB gene.

What type of antigens are found in type O, A, B, and AB blood?

A antigens are in type A blood; B antigens are in type B blood; A and B antigens are found in AB blood; no antigens are found in O blood.

What is true about an individual who is Rh-negative?

The blood lacks the Rh antigen.

Describe a blood platelet.

A tiny, disc-shaped cell fragment found in the blood that helps stop bleeding.

What are Petechiae?

Small, pinpoint red or purple spots that appear on the skin due to bleeding under the skin.

What are the steps in the formation of a blood clot?

1. Vasoconstriction: The injured blood vessel narrows to reduce blood loss. 

2. Platelet plug formation: Platelets stick together to form a temporary plug that stops bleeding. 

3. Coagulation cascade: Clotting factors in the blood activate to stabilize the plug. 

4. Fibrin plug formation: Fibrin strands form a net that traps more platelets and blood cells, creating a stable clot.

What are the steps in the breakdown of a blood clot?

The body senses the injury has healed and releases an activator that turns on plasmin, which breaks down the clot's structure.

Name two substances that dissolve blood clots.

Tissue plasminogen activator and heparin.

What is Prothrombin time used to evaluate?

Blood clotting.

What is a Pulmonary embolism?

A condition where a blood clot (embolus) travels to the lungs and blocks one or more pulmonary arteries.

What does the Frank-Starling law state?

The greater the ED volume of blood filling the heart chambers (preload) before contraction, the stronger the subsequent contraction and the larger the stroke volume of blood pumped out.

What is the formula for Cardiac output?

Heart rate (Hr) multiplied by stroke volume (SV).

What is the primary function of the cardiovascular system?

To transport oxygen and nutrients to all parts of the body.

What is the function of the systemic circuit?

Provides the functional blood supply to all body tissues.

What are the layers of the wall of the heart?

Endocardium, myocardium, and epicardium.

Where are the values located and when do they open?

Tricuspid: between right ventricle and atrium (closed during systole); Pulmonary: between right ventricle and pulmonary trunk (closed during diastole); Mitral: between left ventricle and atrium (closed during systole); Aortic: between left ventricle and aorta (closed during diastole).

How do you position a stethoscope to hear the mitral or aortic valves?

At the fifth intercostal space, midclavicular line on the left side of the chest.

Describe the flow of blood through the heart, lungs, and systemic circulation.

From the vena cava to the right atrium, through the right AV valve to the right ventricle, through the pulmonary valve to the pulmonary trunk, to the pulmonary arteries to the lungs, through the pulmonary veins to the left atrium, through the left AV valve (mitral) to the left ventricle, then to the aorta and the rest of the body back to the vena cava.

Which chambers of the heart contain oxygen-poor blood?

Right atrium and right ventricle.