BMS Exam 2 Flashcards by Avery Abercrombie

What type of intracellular communication?
- Exchange of ions & molecules between adjacent cells across gap junctions.
- Occurs between 2 cells of the same type
- Highly specialized and relatively RARE

Direct Communication

How well did you know this?

Not at all

Perfectly

What type of intracellular communication?
- Chemical signals transfer information from cell to cell within a single tissue.
- Transmission via extracellular fluid specific receptors on target cells
- Example: Blood Clot Formation

Paracrine Communication

How well did you know this?

Not at all

Perfectly

What type of intracellular communication?
- Messages affect the same cells that secrete them
- Chemicals involved are autocrine agents
- Example: prostaglandins secreted by smooth muscle cells cause the same cells to contract

Autocrine Communication

How well did you know this?

Not at all

Perfectly

What type of intracellular communication?
- Endocrine cells release chemicals (hormones) that are transported in the bloodstream
- Alters metabolic activities of many organs
- Target Cells - Have receptors needed to bind and “read” hormonal messages

Endocrine Communication

How well did you know this?

Not at all

Perfectly

Similarity in BOTH Endocrine & Exocrine Glands

Both made up of glandular epithelium

How well did you know this?

Not at all

Perfectly

Endocrine or Exocrine?
Release their contents through a duct that leads to the epithelial surface.

Exocrine Glands

How well did you know this?

Not at all

Perfectly

3 types of exocrine glands

Merocrine, Apocrine, and Holocrine

How well did you know this?

Not at all

Perfectly

Type of Exocrine Gland:
- Release by exocytosis
- Part

Merocrine

How well did you know this?

Not at all

Perfectly

Examples of Merocrine

Sweat & Salivary Glands

How well did you know this?

Not at all

Perfectly

Type of Exocrine Gland:
- Away
- Release by part of the cell being pinched off

Apocrine

How well did you know this?

Not at all

Perfectly

Examples of Apocrine

Mammary & Odorous Sweat Glands

How well did you know this?

Not at all

Perfectly

Type of Exocrine Gland:
- Whole
- Release by entire cell rupturing

Holocrine

How well did you know this?

Not at all

Perfectly

Example of Holocrine

Sebaceous Glands

How well did you know this?

Not at all

Perfectly

3 Classes of Hormones

Amino Acid Derivatives, Peptide Hormones, Lipid Derivatives

How well did you know this?

Not at all

Perfectly

Class of Hormone:
- Small molecules structurally related to amino acids
- Derivates of tyrosine
- Derivatives of tryptophan

Amino Acid Derivatives

How well did you know this?

Not at all

Perfectly

Derivates of Tyrosine

Thyroid Hormones, Catecholamines

How well did you know this?

Not at all

Perfectly

Catecholamines

Epinephrine, norepinephrine, and dopamine

How well did you know this?

Not at all

Perfectly

Derivatives of Tryptophan

Serotonin and Melatonin

How well did you know this?

Not at all

Perfectly

Class of Hormone:
- Chains of amino acids
- Most are synthesized as prohormones
- Glycoproteins
- Short Polypeptides
- Small Proteins
- Includes ALL hormones secreted by hypothalamus, heart, thymus, digestive tract, pancreas, posterior lobe of the pituitary gland, etc.

Peptide Hormones

How well did you know this?

Not at all

Perfectly

Inactive molecules converted to active hormone before or after they are secreted

Prohormones

Examples of Short-Chain Polypeptides

ADH and OXT

How many amino acids are in ADH and OXT?

Examples of Small Proteins in Peptide Hormones

Insulin, Growth Hormones, Prolactin

Derived from arachidonic acid, 20-cacrbon fatty acid molecules that coordinate cellular activities and affect enzymatic processes
Example?

Eicosanoids
Ex: Blood Clotting

What 2 examples have contrasting effects on blood clotting?

Omega 3 and Omega 6

Which class of hormone? Eicosanoids Steroid Hormones – derived from cholesterol Bound to specific transport proteins in the plasma. Retain in circulation longer than peptide hormones.

Lipid Derivatives

Examples of steroid hormones:

Androgens from testes, estrogen and progesterone from ovaries, corticosteroids from adrenal cortex, and calcitriol from kidneys

What is a major difference between Peptide hormones and lipid derived hormones?

Lipid derived stay in circulation longer

Properties of Catecholamines and Peptide Hormones (4)

Not Lipid Soluble Hydrophilic Can't penetrate plasma membrane Bind to extracellular receptor proteins

Properties of Steroid & Thyroid Hormones

Lipid Soluble Can diffuse across plasma membrane & bind to intracellular receptors

Under what conditions are free hormones inactivated? (3)

1. Diffuse out of bloodstream & bind to receptors on target cells 2. Are absorbed and broken down by liver or kidneys 3. Are broken down by enzymes in blood or interstitial fluid

What 2 ways can hormones exist?

Circulate freely or bound to special carrier proteins

Do catecholamines & peptide hormones or steroid & thyroid hormones remain functional for longer?

Steroid and Thyroid

Presence of a hormone triggers a decrease in the number of hormone receptors. When levels of a particular hormone become high, cells become less sensitive to it.

Down-Regulation

Absence of a hormone triggers an increase in the number of hormone receptors. When levels of a particular hormone are low, cells become more sensitive to it.

Up-Regulation

Steroid Hormones can alter rate of DNA transcription in nucleus Alterations in synthesis of enzymes or structural proteins -> directly affect activity & structure of target cell

Genomic Effect

Thyroid Hormones bind to receptors within the nucleus and on mitochondria. - Activated genes or change rate of transcription - Increases rate of ATP production

Non-Genomic Effects

How many hormones does the anterior pituitary produce/secrete?

What class of hormones are the hormones that come from the pituitary gland?

Peptide Hormones

How many hormones does the posterior pituitary release?

2 facts about pituitary hormone transport/binding

Bind to extracellular receptors Use cAMP as second messenger

Location of the pituitary gland in terms of the hypothalamus?

Hangs inferior, connected by infundibulum

Neural Stimuli Stimulates uterine contractions and dilation of the cervix. Positive Feedback Mechanism Responsible for milk "let down" Contribute to parent-newborn bonding

Oxytocin (OXT)

Ensures regulatory hormones reach cells in anterior pituitary before entering general circulation. Blood flow is unidirectional.

Hypophyseal Portal System

Humoral Stimuli Osmoreceptors in hypothalamus trigger release when blood osmolarity increases. Negative Feedback Mechanism Causes blood vessels to contract and increase blood pressure Diabetes insipidus

Antidiuretic Hormone (ADH)

Released by GnRH Stimulates male spermatogenesis and female oocyte maturation production is inhibited by inhibin

Follicle Stimulating Hormone (FSH)

A peptide hormone released by cells in the testes and ovaries that inhibits production of FSH

Inhibin

Stimulates testes to produce testosterone and ovaries to produce estrogen. Lead to secondary sexual development. A surge of this causes ovulation.

Luteinizing Hormone (LH)