PHGY 216 Midterm Exam - Modules 1-3

Endocrine system

A major regulatory system comprised of glands that secrete hormones.

Hormones

Chemical substances secreted into the blood that exert a physiological effect.

Functions of the endocrine system

Include maintaining a constant internal environment, adaptive stress response, growth and development, reproduction, red blood cell production, and integrating with the autonomic nervous system.

Hydrophilic hormones

Highly water soluble hormones that tend to be peptides or proteins, unbound to carrier molecules.

Lipophilic hormones

Hormones that are highly soluble in lipids and require carrier molecules.

Peptide hormone synthesis

Involves synthesis, packaging, storage, and secretion.

Steroid hormone synthesis

Lipophilic hormones released during synthesis; they diffuse across membranes to interact with receptors.

Hypothalamic-Pituitary Axis

A system involving the hypothalamus and the pituitary gland that controls hormone release.

Pituitary gland

A small gland that secretes various hormones, including growth hormone and ACTH.

Vasopressin

A hormone that enhances water retention by kidneys.

Oxytocin

A hormone that stimulates uterine contractions and milk ejection.

Tropic hormones

Hormones that stimulate other endocrine glands to release their hormones.

Thyroid hormones

Produce physiological effects related to metabolism, growth, and development.

Hypothyroidism

A disorder where the thyroid gland does not secrete enough thyroid hormone.

Hyperthyroidism

A condition characterized by increased levels of thyroid hormones.

Goiter

An enlarged thyroid gland, a symptom of both hypo and hyperthyroidism.

Adrenal cortex

The outer layer of the adrenal glands that secretes steroid hormones.

Adrenal medulla

The inner layer of the adrenal glands that secretes catecholamines.

Cortisol

A glucocorticoid that plays a key role in stress response and metabolism.

Insulin

A pancreatic hormone that decreases blood glucose levels.

Glucagon

A pancreatic hormone that increases blood glucose levels.

Growth hormone (GH)

A hormone that promotes growth and metabolism.

Calcium metabolism hormones

PTH, calcitonin, and vitamin D regulate calcium concentrations.

Gametes

Reproductive cells that contain a half set of chromosomes.

Oogenesis

The process of egg formation in females.

Spermatogenesis

The process of sperm formation in males.

Testosterone

The primary male sex hormone that promotes spermatogenesis.

Menstrual cycles

Include the ovarian and uterine cycles governed by hormonal changes.

Fertilization

The process where a sperm cell penetrates and fertilizes an egg cell.

Placentation

The process of forming the placenta for nutrient exchange.

Respiration

Involves the exchange of gases between the body and the environment.

Ventilation

The movement of air in and out of the lungs.

Gas exchange

The diffusion of oxygen and carbon dioxide between the alveoli and blood.

Hemoglobin

An iron-bearing protein in red blood cells that carries oxygen.

Oxygen dissociation curve

Illustrates the relationship between oxygen partial pressure and hemoglobin saturation.

Carbon dioxide transport

Occurs as dissolved gas, bound to hemoglobin, or as bicarbonate.

Central control of breathing

Regulated primarily by the medullary respiratory center.

Chemical control of breathing

Monitored by peripheral chemoreceptors that respond to blood gas levels.

Gas transport abnormalities

Conditions such as hypoxia and hypercapnia affecting oxygen and carbon dioxide transport.

Lung volumes

Measured using a spirometer, including tidal volume and residual volume.

Pulmonary surfactant

Reduces surface tension in the alveoli to prevent collapse.

Pulmonary function testing

Used to evaluate airflow and lung capacities.

Inspiratory reserve volume (IRV)

The maximum volume of air that can be inhaled after a normal inhalation.

Vital capacity (VC)

The maximum volume of air that can be forcibly exhaled after a maximum inhalation.

Hypoxia

Insufficient oxygen reaching the tissues.

Hypercapnia

Elevated carbon dioxide levels in the blood.

Thoracic cavity

The chamber containing the lungs and heart, crucial for respiration.

Mechanical receptors

Receptors that respond to changes in lung volume and pressure.

Pulmonary capillaries

Small blood vessels where most gas exchange occurs.

Diaphragm

Main muscle responsible for inhalation.

Bronchoconstriction

Narrowing of air passages due to smooth muscle contraction.

Bronchodilation

Widening of air passages to decrease resistance.

Work of breathing

Energy expended during inhalation and exhalation.

Anatomical dead space

The volume of airways that does not engage in gas exchange.

Alveoli

Small air sacs in the lungs where gas exchange occurs.

Pulmonary circulation

Pathway through which blood travels to and from the lungs.

Respiratory rate

Frequency of breaths taken per minute.

Chronic obstructive pulmonary disease (COPD)

A group of lung diseases characterized by obstructed airflow.

Asthma

A chronic inflammatory disease leading to airway constriction.

Emphysema

A lung condition that causes shortness of breath due to loss of elasticity.

Lung compliance

The ability of the lung to stretch and expand.

Gas exchange efficiency

Dependent on surface area, membrane thickness, and pressure gradients.

Saturation of hemoglobin

The extent to which hemoglobin is bound to oxygen.

Partial pressure

The pressure of a particular gas in a mixture.

Erythropoiesis

The process of producing red blood cells.

Transpulmonary pressure

The difference between alveolar and pleural pressure.

Respiratory diseases

Conditions that affect breathing and gas exchange.

Homeostasis

The maintenance of a stable internal environment.

Primary endocrine glands

Include the pituitary, thyroid, adrenal glands, and pancreas.

Thyrotropin-releasing hormone (TRH)

Stimulates the release of TSH and prolactin from the anterior pituitary.

Basal metabolic rate (BMR)

The rate of energy expenditure per unit time at rest.

Intermediary metabolism

Involves the breakdown and synthesis of cellular components.

Somatic growth

Increase in the size of an organism due to cellular division and growth.

Hormonal feedback

Mechanisms that regulate hormone levels in the body.

Negative feedback

A process that counteracts changes in a regulated variable.

Insulin-like growth factors (IGFs)

Hormones that mediate growth hormone effects.

Estradiol

A form of estrogen primarily produced in the ovaries.

Follicle-stimulating hormone (FSH)

Stimulates the maturation of follicles in females and sperm production in males.

Luteinizing hormone (LH)

Trigger ovulation and stimulate testosterone production.

Androgens

Male sex hormones responsible for male characteristics.

Estrogens

Female sex hormones responsible for female characteristics.

Menstrual cycle phases

Include the menstrual, proliferative, and secretory phases.

Cervical mucus

Mucus produced by the cervix that changes in consistency during the menstrual cycle.

Prolactin

A hormone that promotes milk production.

Oxytocin roles

Involved in childbirth and milk ejection reflex.

Endocrine glands

Glands that secrete hormones directly into the bloodstream.

Electrical activity of the heart

Can be measured to assess cardiac function.

Circulatory system functions

Includes transporting nutrients, oxygen, and waste products.

Adipose tissue

Body fat used for energy storage.

Peptide hormones

Hormones composed of amino acids that act on target cells.

Glucose metabolism

Involves the processes of glycogenesis and glycogenolysis.

Vitamin D synthesis

Occurs in the skin upon exposure to sunlight.

Mineralocorticoids

Hormones produced by the adrenal cortex that regulate electrolyte balance.

Glucocorticoids

Hormones produced by the adrenal cortex that influence glucose metabolism.

Catecholamines

Hormones like epinephrine and norepinephrine secreted by the adrenal medulla.

Metabolic pathways

Series of chemical reactions in the body to produce energy.

Skeletal muscle function

Includes voluntary movements and posture stabilization.

Cardiovascular responses

Adjustments made by the heart and blood vessels in response to stimuli.

Pulmonary surfactant functions

Helps keep the alveoli open and reduces surface tension.

Chondrocytes

Cells responsible for cartilage formation and maintenance.