Membrane Potential
Overview Equilibrium Potential Overview Nernst equation Used to calculate the equilibrium potential at a given concentration difference of a permeable ion across the cell membrane. $$ V_{eq}= \left ( RT/zF \right )ln\left ( X_{o} /X_{i}\right ) $$ Veq = equilibrium potential for the ion XR = gas constant (8.314 joules per kelvin per mole)T = […]
Heart Sounds
Overview Heart sounds Table: Heart sounds Sound Timing Association S1 Isovolumetric contraction (beginning of systole) Closure of atrioventricular valves S2 Isovolumetric relaxation (beginning of diastole) Closure of semilunar valves S3 Rapid filling of ventricles (early diastole) Normal in pregnant women, children, athletes Ventricular dilation (e.g., congestive heart failure) S4 Late filling of ventricles by atrial […]
Kidney Function Tests
Overview Anatomy of the nephron Nephron: Parts of nephron: Physiology of urine production Urine is a waste by-product composed of excess water and metabolic waste filtered out of the bloodstream by nephrons. Urine formation is a stepwise process. Serologic Parameters of Renal Function Creatinine and estimated glomerular filtration rate (eGFR) The most commonly used […]
Synapses and Neurotransmission
Synapses Anatomy of the synapse In the CNS, a synapse is a structural part of a neuron that passes an electrical or chemical signal to another neuron or to a target cell. Neuron structure: At a synapse: Synapses by location Types of synapses Electrical synapses: Chemical synapses: Neurotransmitters > 500 unique neurotransmitters have been identified […]
Gonadal Hormones
Overview Definition Gonadal hormones: The gonadal hormones are produced by the human gonads: the testes and ovaries. These hormones include: Gendered terminology: Recognizing the complexity and sensitive nature around gendered terminology, for the purposes of this document: Hypothalamic-pituitary-gonadal (HPG) axis Hormones secreted by the gonads are stimulated by, and help to regulate, the hypothalamic-pituitary-testicular (HPT) […]
Hypothalamic and Pituitary Hormones
Overview Definitions Hormones are messenger molecules that are synthesized in one part of the body and exert specific regulatory effects on another part of the body. Hypothalamic hormones: Secreted directly by neurons from the hypothalamus Act on the pituitary gland Represent the point of integration between the CNS and endocrine system Pituitary hormones: Secreted from […]
Adrenal Hormones
Overview Regions of the adrenal gland The adrenal glands have 2 primary areas with separate functions and regulatory mechanisms. Hypothalamic-pituitary-adrenal (HPA) axis Hormones secreted by the adrenal cortex (not the medulla) are controlled by, and help regulate, the HPA axis. Adrenal Cortex Hormones: Mineralocorticoids Mineralocorticoid overview The renin-angiotensin-aldosterone system (RAAS) The RAAS is one of […]
Calcium Hemostasis and Bone Metabolism
Overview Principal regulators of bone metabolism The 3 primary regulators of bone metabolism are: Purposes of bone metabolism Review of bone anatomy Review of calcium homeostasis Calcium has many important functions in the body and its levels must be tightly regulated to stay around 10 mg/dL. Calcium is the most abundant mineral in the body. […]
Thyroid Hormones
Overview Hormones released by the thyroid gland The primary hormones released from the thyroid include: The thyroid hormones, triiodothyronine (T3) and thyroxine (T4): Produced by follicular cells Act on most cells/tissues in the body Stimulate metabolism and oxygen consumption → primary regulators of body metabolism Increase circulation and respiration Promote nervous system and skeletal development […]
Hormones: Overview and Types
Hormones and Endocrine Glands Definition Hormones are messenger molecules that are synthesized in one part of the body and move through the bloodstream to exert specific regulatory effects on another part of the body. General functions of hormones Major functions of hormones include: Endocrine glands and organs The major endocrine glands in the body include: […]