Human Tissues, Respiratory, and Circulatory System Overview for Biology

What do plasma cells produce?

High volumes of antibodies.

What is opsonization?

The process of tagging a pathogen for elimination by phagocytosis.

How do antibodies neutralize pathogens?

By blocking a pathogen from functioning by binding to key areas.

What is agglutination in the context of antibodies?

The clumping together and immobilization of pathogens.

What role do memory B cells play in the immune response?

They rapidly proliferate to produce a more rapid and effective secondary immune response upon re-exposure to the same pathogen.

Where do T cells originate and mature?

T cells originate from the bone marrow and mature in the thymus.

What do T cell receptors bind to?

Antigen fragments presented on MHC (Major Histocompatibility Complex).

What happens when a T cell recognizes a foreign antigen?

The T cell becomes activated and undergoes clonal selection to produce various cell types.

What are the four types of cells produced from activated T cells?

Cytotoxic T cells, Helper T cells, Suppressor T cells, and Memory T cells.

What is the function of Cytotoxic T cells?

They destroy infected cells by releasing perforins that trigger apoptosis.

What is the role of Helper T cells?

They stimulate the activation of B cells and cytotoxic T cells and release cytokines to recruit other immune cells.

What do Suppressor T cells do?

They play a negative feedback role in the immune system to prevent autoimmune responses.

What is the function of Natural Killer Cells (NKCs)?

They detect and destroy virally-infected or tumor cells that lack MHC I receptors.

What is the process of T cell positive selection?

T cells that can bind to MHC survive, while those that cannot are eliminated.

What occurs during T cell negative selection?

T cells that bind too tightly to self-antigens are eliminated.

What is immune tolerance?

The ability to prevent an immune response against self-antigens.

What distinguishes innate immunity from adaptive immunity?

Innate immunity is non-specific and fast, while adaptive immunity is specific and slower.

What is active immunity?

Immunity acquired and created in the body after direct exposure to a pathogen.

What is passive immunity?

Immunity acquired from external sources, such as antibodies transferred from mother to baby.

What is the purpose of vaccines?

To train the immune system to recognize and respond to future infections without the risk of actual pathogen exposure.

What are antibiotics?

Chemicals derived from bacteria or fungi that can kill microorganisms.

What is the mnemonic for the relative amount of immune cells?

Never Let Monkeys Eat Bananas (Neutrophils > Lymphocytes > Monocytes > Eosinophils > Basophils).

What is the primary role of hormones in the endocrine system?

To act as chemical messengers that coordinate specific functions in the body.

What is the difference between hormonal and neuronal signaling?

Hormonal signaling is slower and more widespread, while neuronal signaling is faster and more direct.

What are peptide hormones made of?

Amino acids.

What are steroid hormones derived from?

Cholesterol.

What are the four major secondary messengers?

cAMP, IP3, DAG, and calcium (Ca2+).

What is the pathway of steroid hormones?

They diffuse into the cell, bind to receptors, and alter gene expression.

What are the two major types of hormones?

Thyroid Hormones (hydrophobic, bind intracellularly) and Catecholamines (hydrophilic, bind extracellularly).

How do thyroid hormones behave?

They behave like steroid hormones by binding receptors in the nucleus to increase gene transcription.

What is homeostasis?

The process by which a stable physiological state is maintained via feedback loops.

What are positive feedback loops?

Loops where the product of a process further activates that process, creating more product.

What are negative feedback loops?

Loops where the product of a process inhibits that process, preventing further production.

What is the role of the hypothalamus?

It maintains homeostasis and monitors the body's external and internal environment.

What type of hormones does the hypothalamus produce?

Exclusively peptide hormones.

What is the function of the pituitary stalk (infundibulum)?

Creates direct neuronal connection between the hypothalamus and posterior pituitary, and a vascular connection to the anterior pituitary.

What hormones are synthesized by the hypothalamus?

Antidiuretic hormone (ADH) and oxytocin.

What is Gonadotropin-Releasing Hormone (GnRH)?

A hormone that stimulates the anterior pituitary to release FSH and LH.

What is the function of Corticotropin-Releasing Hormone (CRH)?

Stimulates the anterior pituitary to release ACTH.

What does Thyrotropin-Releasing Hormone (TRH) do?

Stimulates the anterior pituitary to release TSH.

What is the role of Growth Hormone-Releasing Hormone (GHRH)?

Stimulates the anterior pituitary to release GH.

What is Somatostatin?

A hormone that inhibits the anterior pituitary from releasing GH and TSH.

What does dopamine do in the endocrine system?

Inhibits the anterior pituitary from releasing prolactin.

How do releasing/inhibiting hormones travel from the hypothalamus to the anterior pituitary?

They are released into capillary networks and transported via hypophyseal portal veins.

What is the anterior pituitary responsible for?

Regulating hormone production of other glands and producing both direct and tropic hormones.

What is the function of Melanocyte-Stimulating Hormone (MSH)?

Stimulates melanocytes to produce and release melanin.

What does Prolactin do?

Stimulates mammary gland cells to produce milk in females.

What is the role of Growth Hormone?

Stimulates bone and muscle growth; increases cell size, mitosis, and rate of protein synthesis.

What is the function of Thyroid Stimulating Hormone (TSH)?

Stimulates the thyroid gland to secrete T3 & T4.

What does Adrenocorticotropic Hormone (ACTH) stimulate?

Stimulates adrenal cortex to release glucocorticoids.

What is the role of Follicle-Stimulating Hormone (FSH) in males?

Stimulates testes to produce sperm (spermatogenesis).

What does Luteinizing Hormone (LH) trigger in females?

Triggers ovulation and corpus luteum formation, leading to progesterone release.

What is the function of the posterior pituitary?

Stores and releases hormones from the hypothalamus; does not synthesize its own hormones.

What does ADH (Vasopressin) regulate?

Regulates water levels in the body by increasing permeability at the collecting duct and distal convoluted tubule.

What is the role of oxytocin?

Stimulates uterine contractions during childbirth and milk ejection from mammary glands.

What hormone does the pineal gland produce?

Melatonin, which regulates circadian rhythm.

What are the functions of thyroid hormones (T3 and T4)?

Increase body metabolism and heart rate; require iodine for synthesis.

What is calcitonin's role in the body?

Lowers blood calcium levels by inhibiting osteoclast activity and stimulating osteoblasts.

What does parathyroid hormone (PTH) do?

Raises calcium levels in blood and lowers blood phosphate levels.

What is the function of glucocorticoids?

Stimulate gluconeogenesis in the liver and trigger the breakdown of proteins and fats for energy.

What do catecholamines like epinephrine and norepinephrine trigger?

The body's 'fight-or-flight' response, increasing blood glucose levels and heart rate.

What are the exocrine and endocrine functions of the pancreas?

Exocrine: secretes digestive enzymes; Endocrine: regulates blood sugar levels through Islets of Langerhans.

What do alpha cells in the pancreas secrete?

Glucagon, which increases blood glucose levels.

What do beta cells secrete?

Insulin, which decreases blood glucose levels.

What is the function of somatostatin secreted by delta cells?

Inhibits release of insulin and glucagon, suppresses GI hormone release, and reduces gastric motility.

What hormones do the gonads produce?

Gametes and steroid hormones, stimulated by FSH and LH.

What is the role of testosterone in males?

Affects libido, fat distribution, and bone/muscle mass, and establishes male secondary sex characteristics.

What are the secondary sex characteristics established by estrogen in females?

Breast development, hip widening, onset of menstruation, and pubic hair.

What is the role of progesterone during early pregnancy?

Maintains early pregnancy by thickening the endometrial wall.

What are prostaglandins?

Non-hormone local signaling molecules that cause uterine contractions, regulate inflammation, and enhance pain sensitivity.

What does gastrin stimulate?

The secretion of HCl from stomach cells.

What is the function of cholecystokinin (CCK)?

Stimulates release of bile and pancreatic digestive enzymes, slowing gastric motility.

What does secretin do?

Stimulates release of bicarbonate from the pancreas to neutralize acidic chyme.

What hormone does the pineal gland secrete?

Melatonin, which regulates circadian rhythm.

What is the function of GnRH from the hypothalamus?

Stimulates the anterior pituitary to release FSH and LH.

What does follicle-stimulating hormone (FSH) do in males?

Stimulates spermatogenesis.

What is the role of luteinizing hormone (LH) in females?

Stimulates progesterone release, corpus luteum formation, and triggers ovulation.

What does thyroid-stimulating hormone (TSH) stimulate?

Stimulates the thyroid gland to release T3 and T4.

What is the function of adrenocorticotropic hormone (ACTH)?

Stimulates the adrenal cortex to release glucocorticoids.

What does growth hormone (GH) stimulate?

Stimulates bone and muscle growth and various metabolic functions.

What is the primary function of oxytocin?

Stimulates uterine contractions and milk ejection.

What does vasopressin (ADH) promote?

Retention of water by the kidneys.

What is the role of calcitonin?

Lowers blood calcium levels and builds up bone.

What is the function of thymosin?

Stimulates T-lymphocyte development.

What do adrenal medulla hormones (epinephrine/norepinephrine) do?

Raise blood glucose levels and increase metabolic activities.

What is the function of glucocorticoids (Cortisol)?

Raises blood glucose levels.

What do mineralocorticoids (Aldosterone) promote?

Reabsorption of Na+ in kidneys, increasing water retention and raising blood pressure.

What do the testes produce?

Sperm and sex hormones, including testosterone.

What is the function of the oviducts (Fallopian tubes)?

Allow eggs to move from an ovary to the uterus; fertilization occurs here.

What is the role of the uterus?

A muscular chamber where the embryo develops until birth.

What is the function of the cervix?

Regulates the flow of substances in and out of the uterus.

What is the pathway of sperm during ejaculation?

Epididymis → Vas Deferens → Ejaculatory Duct → Urethra.

What do seminal vesicles secrete?

Seminal fluid that provides a liquid medium for sperm and energy for sperm movement.

What is the function of the prostate gland?

Produces alkaline fluid to counteract the acidic environment of the female reproductive tract.

What is the purpose of gametogenesis?

Meiotic cell divisions that produce either eggs (oogenesis) or sperm (spermatogenesis).

What is a follicle?

A cell structure that surrounds and supports egg development by providing nutrients, regulating meiosis, and producing estrogen.

What are the two main processes that are interdependent in female gamete development?

Oogenesis and follicular development.

What occurs to primordial germ cells before birth?

They move into the ovaries and differentiate into oogonia (2n).

What do primary oocytes reside within?

Primordial follicles composed of granulosa cells.

At what stage do primary oocytes stop meiosis until puberty?

Prophase I.