Skip to main content
Indietro

Anatomy & Physiology: Endocrine and Cardiovascular Systems Study Guide

I pulsanti di controllo sono stati cambiati in modalità "navigazione".
1/30

Termini in questo insieme (30)

  • Endocrine Gland

    Ductless gland that secretes hormones directly into the bloodstream to act on distant target cells.

  • Target Cell

    A specific cell possessing protein receptors that uniquely bind a particular hormone.

  • Paracrine Secretion

    Chemical signal released into extracellular fluid to act on neighboring, different cell types.

  • Autocrine Secretion

    Chemical signal that acts on the same cell or same cell type that secreted it.

  • Synergism

    Interaction where two or more hormones act together to produce an effect greater than the sum of their individual effects.

  • Antagonism

    Interaction where one hormone opposes or inhibits the action of another hormone.

  • Amino Acid–Based Hormones

    Hydrophilic hormones (amines, peptides, proteins) that travel freely in blood and bind to cell-surface receptors.

  • Steroid Hormones

    Lipophilic hormones derived from cholesterol that require transport proteins and bind to intracellular receptors.

  • Second-Messenger System

    Hydrophilic hormone binds membrane receptor → activates G-protein → activates adenylate cyclase → converts ATP to \(cAMP\) → activates Protein Kinase A to alter cell activity.

  • Direct Gene Activation

    Lipophilic hormone diffuses into cell → binds intracellular receptor → hormone-receptor complex enters nucleus → alters gene transcription and protein synthesis.

  • Hypothalamus–Pituitary Axis: Infundibulum

    Stalk connecting the hypothalamus to the pituitary gland.

  • Anterior Pituitary

    Glandular tissue linked to hypothalamus via the Hypophyseal Portal System, secretes hormones like TSH, ACTH, LH, FSH, GH, and PRL.

  • Posterior Pituitary

    Neural tissue storing and releasing hormones made in hypothalamus, including ADH and Oxytocin.

  • Thyroid Gland: Follicular Cells

    Produce \(T3\) and \(T4\), regulating basal metabolic rate, body temperature, and growth.

  • Thyroid Gland: Parafollicular Cells

    Secrete Calcitonin, which lowers blood calcium by inhibiting osteoclasts.

  • Parathyroid Glands: Chief Cells

    Produce Parathyroid Hormone (PTH), raising blood calcium by stimulating osteoclasts, increasing renal calcium reabsorption, and activating Vitamin D.

  • Adrenal Cortex Zones and Secretions

    Zona Glomerulosa: Mineralocorticoids (Aldosterone); Zona Fasciculata: Glucocorticoids (Cortisol); Zona Reticularis: Androgens (DHEA).

  • Adrenal Medulla

    Chromaffin cells secrete Epinephrine and Norepinephrine for sympathetic "fight-or-flight" responses.

  • Pancreas Islets: Alpha and Beta Cells

    Alpha cells produce Glucagon (raises blood glucose); Beta cells produce Insulin (lowers blood glucose).

  • Heart Wall Layers

    Epicardium: visceral serous pericardium; Myocardium: cardiac muscle; Endocardium: inner endothelial lining.

  • Atrioventricular (AV) Valves

    Tricuspid valve on right; Bicuspid (Mitral) valve on left; Chordae tendineae prevent valve prolapse during ventricular contraction.

  • Semilunar (SL) Valves

    Pulmonary valve between right ventricle and pulmonary trunk; Aortic valve between left ventricle and aorta.

  • Cardiac Muscle Action Potential Phases

    Phase 0: Na+ influx; Phase 1: initial K+ efflux; Phase 2: Ca2+ influx balances K+ efflux (plateau); Phase 3: K+ efflux; Phase 4: resting potential (~-90 mV).

  • Intercalated Discs

    Contain desmosomes for mechanical anchoring and gap junctions for electrical coupling of cardiomyocytes.

  • Cardiac Conduction System Sequence

    SA node → AV node (delay) → AV bundle → bundle branches → Purkinje fibers for coordinated contraction.

  • ECG Waves and Intervals

    P wave: atrial depolarization; QRS complex: ventricular depolarization; T wave: ventricular repolarization; P-R interval: atrial to ventricular depolarization delay.

  • Phases of the Cardiac Cycle

    1. Ventricular filling (AV valves open); 2. Isovolumetric contraction (AV valves close, SL closed); 3. Ventricular ejection (SL valves open); 4. Isovolumetric relaxation (SL valves close).

  • Stroke Volume (SV) Formula

    SV = End-Diastolic Volume (EDV) − End-Systolic Volume (ESV)

  • Cardiac Output (CO) Formula

    CO = Heart Rate (HR) × Stroke Volume (SV)

  • Factors Regulating Stroke Volume

    Preload (sarcomere stretch), Contractility (strength of contraction), Afterload (arterial backpressure).