Lecture 12 - Endocrine System Flashcards
What does the endocrine system do?
Works with the nervous system to control homeostasis
Function of Endocrine vs Nervous system
Endocrine
- > releases hormones into bloodstream from ductless glands and travel throughout body (longer lasting)
Nervous
- > releases neurotransmitters to excited/inhibit nerves, muscles, and gland cells (instant, brief )
Explain how hormone receptors effect target cells
- > endocrine cells release hormones into the blood stream
- > these hormones don’t affect all other cells, they only affect cells with certain receptors
- > target cells must have a specific hormone receptor for the cell do be affected by the hormone in question
Explain a negative feedback loop
- > the stimulus starts the process
- > the end result in to negate/ reverse the effects of the stimulus
- > i.e low blood sugar, insulin comes in to raise/ fix levels
Explain a positive feedback loop
- > does not produce a counteracting effect
- > stimulus accelerates the process until the stimulus is removed, then the process halts
- > childbirth, breastfeeding
List all major endocrine organs
What does the hypothalamus control (endocrine system)
- > controls and oversees most endocrine functions
- > interface between the nervous system and endocrine systems
- > master gland of the endocrine system
Where is hypothalamus and pituitary gland located
in the inferior region of the diencephalon, just superior to the pituitary
HOW does the hypothalamus control endocine activity
- Controls the release of six regulatory hormones from the ANTERIOR pituitary gland
- Secretes oxytocin (OT) and adtidieuretic hormone (ADH) from the POSTERIOR pituitary gland
- Controls the stimulation and secretion activities of the adrenal medulla
Physical characteristics of the pituitary gland
- > housed within the sella turnica of the sphenoid bone
- > connected to the hypothalamus by thin stalk called infundibulum
- > divided into anterior and posterior lobes
Thymus vs thalamus
Thymus - > imune system gland
Thyroid - > endocrine system gland
What makes up the adenohypophysis
*NOT HYPOTHESIS; ALSO KNOWN AS ANTERIOR PITUITARY*
- > Pars Distalis
- > Pars Intermedia
- > Pars Tuberalis
What are the six hormones of the anterior pituitary
- Growth Hormone (GH) - also called somatotropin
- Follicle stimulating hormone (FSH)
- Luteinizing hormone
- Prolactin (PRL)
- Adrenocorticotropin hormone (ACTH)
- Thyroid Stimulating hormone (TSH)
Infundibulum
the hollow stalk which connects the hypothalamus and the posterior pituitary gland
Explain the function of the human growth hormone
- > produced by somatotrophic cells
- > increases cell growth and cell division by increasing their uptake of amino acids and synthesis of protein
- > common targets cells are liver, skeletal muscles, cartilage and bone ( especially collagen)
Hyposecretion vs hypersecretion of human growth hormone
Hyposecretion - > Dwarfism
Hypersecretion - > Giantism
Explain the functions of the follicle stimulating hormone
*released by gonadotrophs*
- > initiates the formation of follicles within the ovary
- > stimulates follicle cells to secrete estrogen
- > stimulate sperm production in testes
Explain the function of luteinizing hormone
*produced by gonadotrophs*
In females…
- > triggers ovulation
- > secretion of estrogen and progesteron
In males…
- > stimulates secretion of testosterone