Wk 5 Endorine Glands- Hormones Flashcards
How are endocrine and exocrine glands different
An endocrine gland secretes hormones into the blood via the ECF (the anterior pituitary and the thyroid) and an exocrine gland secretes onto an epithelial surface or into a duct (sweat glands and gastric glands )
Define a hormone
A compound secreted by one dell that travels through the circulatory system to affect the activities of cells in another part of the body
Hormones can be classified into 3 structures, what are they?
Peptide hormones
Lipid based (steroid) hormones
Amino acid derivatives (anime hormones)
Name some lipid based hormones
Testosterone , oestrogen, progesterone and cortisol
Cellular activities are coordinated by the exchange of ions/molecules across gap junctions between adjacent cells.
Is it true that the 2 cells must be of the same type and be in extensive physical contact
Yes!
When does paracrine communication occur?
It occurs within a single tissue to transfer information via paracrine factors (normal hormones)
Autocrine signalling : a cell ______ a hormone or ______ messenger that bonds to a _______ receptor on the same cell, leading to changes in the cell
Autocrine signalling : a cell SECRETS a hormone or CHEMICAL messenger that bonds to a AUTOCRINE receptor on the same cell, leading to changes in the cell
How do hormones alter activities of target cells of different tissues
They change the types or quantities produced of important enzymes and structural proteins
What’s the primary role of the endocrine system
Maintains homeostasis in the body through regulating the secretion of hormones to respond to changing environment conditions
What’s another role for the endocrine system
Regulates long term changes in the body
For example- development during puberty and life long maintenance of the reproductive system
Name some similarities between the nervous system and the endocrine system
Both release chemicals that bind to specific receptors on their target cells
Both maintain homeostasis
Both systems are mainly controlled by negative feedback
Both have chemical messengers the same. Such as adrenaline and nonadrenlim even
When might a hormone be deactivated
When they :
Diffuse out of the blood stream and bind to receptors on target cells
Are absorbed and broken down by liver cells and removed by the kidney
Or are broken down by enzymes in blood plasma
To respond to a hormone, a target cell must have the appropriate receptor
If a cell lacks a receptor for a particular hormone, what effect will it have on the the cell?
No effect whatsoever.
A cell is a target because why
It has a specific receptor for the hormone
Hormones alter cell activity by doing wat
Turning on a specific gene on or off
Controlling transport (open/close membrane channel) Changing the rate of enzymatic reaction.
Hormones released from the posterior pituitary are synthesised in the hypothalamus
True or false
Tru
The hypothalamus secretes specific regulatory hormones that affect the anterior pituitary
What are these two hormones called
Releasing hormones (RHs) Inhibiting hormones (IHs)
What are the three functions of the hypothalamus
Subconscious control of skeletal muscle contraction
Control of autonomic functions including regulating heart rate/bp/respiration and digestion
Coordinating the nervous and endocrine systems by neuroendocrine control
Secrets ADH which reduces water loss at kidneys , oxytocin which stimulates smooth muscle contraction in the uterus and mammary glands in female and the sperm duct and prostate gland in males
Controls emotional and behavioural drives such as hunger and thirst
Regulates body temp
Releasing hormones (RHs) prevent the synthesis and secretion of hormones from the anterior pituitary
True or false
False Inhibiting hormones (IHs) prevent the synthesis and secretion of hormones from the anterior pituitary
And Releasing hormones (RHs) stimulate the synthesis and secretion of one or more hormones from the anterior pituitary
Tropic/trophic (trope= a turning) turn on
4!
TSH, ACTH, FSH, LH
The TSH hormone stands for what
Thyroid stimulating
What controls the endocrine system
Our emotions, perceptions, cognitions, experiences, behaviour, our response to the environment = higher brain areas -hypothalamus -pituitary gland -other endocrine glands
