Related Concept Videos

Target Cell Response to Hormones01:22

Target Cell Response to Hormones

Hormones intricately bind to receptors on the surface or within target cells, initiating a cascade of cellular responses.
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
Major Hormones and Their Functions01:27

Major Hormones and Their Functions

Hormones, the biochemical messengers produced by endocrine glands, are pivotal in regulating bodily functions and maintaining homeostasis. Each hormone's balance is crucial; imbalances can lead to significant physiological disruptions. Major hormones include oxytocin, cortisol, epinephrine, estrogen, testosterone, thyroxine, growth hormone, insulin, and glucagon.
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and lactation.
Regulation of Hormone Secretion01:19

Regulation of Hormone Secretion

Regulation of hormone secretion is a finely tuned orchestration driven by various types of stimuli, encompassing neural, humoral, and hormonal signals. Environmental cues instigate neural stimuli, where action potentials traverse nerve fibers to reach their designated targets. An illustrative scenario is the body's response to stress, wherein the sympathetic nervous system releases epinephrine from the adrenal glands, inducing the well-known 'fight or flight' reaction.
Humoral stimuli,...
Hormonal Regulation of the Menstrual Cycle01:22

Hormonal Regulation of the Menstrual Cycle

The ovarian cycle regulates endometrial changes throughout a single menstrual cycle via the coordinated action of gonadotrophin-releasing hormone (GnRH) and gonadotrophins.
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Menopause01:28

Menopause

Menopause, a natural biological process marking the end of a woman's fertility, typically occurs between the fifth and sixth decade of life. This phase is characterized by the exhaustion of the ovarian follicle pool, leading to less responsive ovaries despite the high levels of Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). The consequential decrease in estrogen production results in symptoms like hot flashes, heavy sweating, headaches, hair loss, muscle pains, vaginal...
Hyperthyroidism I: Introduction01:25

Hyperthyroidism I: Introduction

Hyperthyroidism is a type of thyrotoxicosis characterized by the thyroid gland's overproduction of the thyroid hormones triiodothyronine (T3) and thyroxine (T4). This hormone excess increases the basal metabolic rate and enhances sensitivity to catecholamines.DiagnosisDiagnosis is based on clinical features and biochemical testing. It typically shows suppressed thyroid-stimulating hormone (TSH) levels below 0.4 mIU/L, with elevated free T3 and/or T4. Additional tests, including thyroid...