Endocrine System Flashcards
1
Q
Regulates body activities by releasing hormones (chemical messengers) into the bloodstream, where they are carried throughout the entire body
A
Endocrine System
2
Q
Two body systems are responsible for sending and receiving sensory information and coordinating body responses
A
Nervous system and Endocrine system
3
Q
They are sometimes referred to as the neuro-endocrine system
A
Nervous system and Endocrine system
4
Q
Regulate the chemical composition and volume of the internal environment (extracellular fluid)
A
Hormone
5
Q
Help regulate metabolism and energy balance
A
Hormone
6
Q
Help regulate contraction of smooth and cardiac muscle fibers and secretion by glands
A
Hormone
7
Q
Help maintain homeostasis, despite disruptions, such as infection, trauma, emotional stress, dehydration, starvation, hemorrhage, and temperature extremes
A
Hormone
8
Q
Regulate certain activities of the immune system
A
Hormone
9
Q
Play a role in the smooth, sequential integration of growth and development
A
Hormone
10
Q
Contribute to the basic processes of reproduction, including gamete production, fertilization, nourishment of the embryo and fetus, delivery, and nourishment of the newborn
A
Hormone
11
Q
Two kinds of glands
A
Exocrine glands and Endocrine glands
12
Q
Secrete their products into body ducts, which carry the products into body cavities, the lumen of an organ, or the outer surface of the body
A
Exocrine glands
13
Q
- Sudoriferous glands
- Sebaceous glands
- Mucous glands
- Digestive glands
A
Exocrine glands
14
Q
Secrete their products (hormones) into the extracellular space around the secretory cells. The secretions diffuse into capillaries and are carried throughout the body by the circulatory system
A
Endocrine glands
15
Q
The endocrine system is composed of the body’s endocrine glands. These include:
A
-Pituitary
-Thyroid
-Parathyroid
-Adrenal
-Pineal glands
-Pancreatic islets
16
Q
There are also many organs that have cells which secrete hormones, but are not exclusively endocrine organs. These include:
A
-Hypothalamus
-Thymus
-Pancreas
-Ovaries
-Testes
-Kidneys
-Stomach
-Liver
-Small intestine
-Skin
-Heart
-Placenta
17
Q
The specific cells which are affected by a hormone
A
Target cells
18
Q
Hormones influence their target cells by binding to proteins or glycoproteins in the cell membrane
A
Receptors
19
Q
Can have very powerful effects even when present in very low concentrations
A
Hormones
20
Q
How many different hormones produced in the human body?
A
Approximately 50
21
Q
Other name of pituitary gland
A
Hypophysis
22
Q
It attached to the hypothalamus at the base of the brain
A
Pituitary gland
23
Q
The major integrating link between the nervous and endocrine system
A
Hypothalamus
24
Q
It sometimes called the “master” endocrine gland
A
Pituitary gland
25
Both regulate virtually all aspects of growth, development, metabolism, and homeostasis
Hypothalamus and Pituitary gland
26
The pituitary gland can be divided into the
Posterior pituitary and anterior pituitary
27
- It is the size of a pea
- weighs about 500mg
- consists of two main parts that originate from different types of cells
Pituitary gland
28
It is an up-growth of “glandular epithelium” from the pharynx
Anterior pituitary ( adenohypophysis )
29
It is an down-growth of “nervous tissue from the brain”
Posterior pituitary ( neurohypophysis )
30
It is an down-growth of “nervous tissue from the brain”
Posterior pituitary ( neurohypophysis )
31
There is a ____ between the hypothalamus and the posterior pituitary
network of nerve fibres
32
A small structure at the base of the brain which releases a wide variety of hormones that, in turn, control the activity of the body’s other hormone glands
Pituitary gland
33
This is from branches of the internal carotid artery
Arterial blood
34
It is supplied indirect by blood that has already passed through a capillary bed in the hypothalamus
Anterior lobe
35
It is supplied directly ( blood supply )
Posterior lobe
36
The influence of the hypothalamus on the pituitary gland
The hypothalamus controls release of hormones from both the anterior and posterior pituitary but in different ways
37
HORMONES OF THE PITUITARY GLAND
(Anterior Pituitary)
1. Growth hormone (GH)
2. Thyroid stimulating hormone (TSH)
3. Adrenocorticotrophic hormone (ACTH)
4. Prolactin (PRL)
5. Luteinising hormone (LH)
6. Follicle stimulating hormone (FSH)
38
HORMONES OF THE PITUITARY GLAND
(Posterior Pituitary)
1. Vasopressin or Antidiuretic hormone (ADH)
2. Oxytocin
39
Works as a unit with the hypothalamus
Posterior pituitary
40
Although the ___ does not synthesize its own hormones, it does store and release oxytocin (OT) and antidiuretic hormone (ADH) produced in the hypothalamus
Posterior pituitary
41
It controls uterine contractions during delivery and milk ejection during breastfeeding
Oxytocin (OT)
42
It causes retention of body water, controlling the body’s water-balancing mechanism
Antidiuretic hormone (ADH)
43
Secretes hormones that control a wide range of bodily activities
Anterior pituitary
44
- Regulates the anterior pituitary by producing releasing hormones
- Stimulate release of anterior pituitary gland hormones and inhibiting hormones that suppress release of anterior pituitary gland hormones
Hypothalamus
45
It has five (5) principle types of cells which secrete seven major hormones
Anterior pituitary
46
Which stimulates general body growth and regulates certain aspects of metabolism
Growth hormone (GH)
47
Which controls secretions and other activities of the thyroid gland
Thyroid stimulating hormone (TSH)
48
Both stimulate the secretion of estrogen and progesterone and the maturation of oocytes in the ovaries and the secretion of testosterone and sperm production in the testes
Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH)
49
Which initiates milk production in the mammary glands
Prolactin (PRL)
50
Stimulates the adrenal cortex to secrete glucocorticoids
Adrenocorticotrophic hormone (ACTH)
51
Affects skin pigmentation
Melanocyte-stimulating hormone (MSH)
52
Regulates metabolism, promotes tissue growth especially of bones and muscles
Growth hormone
53
Stimulates growth and activity of thyroid gland and secretion of T3 and T4
Thyroid stimulating hormone
54
Stimulates the adrenal cortex to secrete glucocorticoids
Adrenocorticotrophic hormone
55
Stimulates growth of breast tissue and milk production
Prolactin
56
- Stimulates production of sperm in the testes
- Stimulates secretion of oestrogen by the ovaries, maturation of ovarian follicles, ovulation
Follicle stimulating hormone
57
- Stimulates secretion of testosterone by the testes
- Stimulates secretion of progesterone by the corpus luteum
Luteinising hormone
58
There are three main types of cells in the pancreatic islets
1. Alpha cells
2. Beta cells
3. Delta cells
59
Which secrete glucagon
Alpha cells
60
Which are the most numerous, secrete insulin
Beta cells
61
Which secrete somatostatin
Delta cells
62
This hormone, also produced by the hypothalamus, inhibits the secretion of both insulin and glucagon in addition to inhibiting the secretion of growth hormone (GH) from the anterior pituitary
Somatostatin (GHRIH)
63
This is the most abundant hormone synthesized by the anterior pituitary
Growth hormone
64
It stimulates growth and division of most body cells but especially those in the bones and skeletal muscles
Growth hormone (GH)
65
Body growth in response to the secretion of __ is evident during childhood and adolescence, and thereafter secretion of __ maintains the mass of bones and skeletal muscles
Growth hormone (GH)
66
It also regulates aspects of metabolism in many organs ( e.g. liver, intestines and pancreas )
Growth hormone ( GH)
67
Its release is stimulated by Growth Hormone Releasing Hormone (GHRH) and suppressed by Growth Hormone Release Inhibiting Hormone (GHRIH), also known as __
Somatostatin
68
Both of which are secreted by the hypothalamus
Growth Hormone Releasing Hormone (GHRH) and Growth Hormone Release Inhibiting Hormone (GHRIH)
69
- Secretion of __ is greater at night during sleep and is also stimulated by hypoglycemia (low blood sugar), exercise and anxiety
- Secretion peaks in adolescence and then declines with age
Growth Hormone (GH)
70
The release of this hormone is stimulated by thyrotrophin releasing hormone (TRH) from the hypothalamus
Thyroid stimulating hormone (TSH)
71
It stimulates growth and activity of the thyroid gland, which secretes the hormones T4 and T3
Thyroid stimulating hormone (TSH)
72
T4 means
Thyroxine
73
T3 means
Triiodothyronine
74
This hormone the release is lowest in the early evening and highest during the night
Thyroid stimulating hormone (TSH)
75
This hormone from the hypothalamus promotes the synthesis and release of Adrenocorticotrophic Hormone (ACTH) by the anterior pituitary
Corticotrophin Releasing Hormone (CRH)
76
This increases the concentration of cholesterol and steroids within the adrenal cortex
Adrenocorticotrophic Hormone (ACTH)
77
This hormone levels are highest at about 8 am and fall to their lowest about midnight
Adrenocorticotrophic Hormone (ACTH)
78
This hormone levels are highest at about 8 am and fall to their lowest about midnight
Adrenocorticotrophic Hormone (ACTH)
79
This hormone is secreted during pregnancy to prepare the breasts for lactation ( milk production ) after childbirth
Prolactin
80
The blood level of prolactin is stimulated by __ released from the hypothalamus
Prolactin Releasing Hormone (PRH)
81
It is lowered by __ and by an increased blood level of prolactin
Prolactin Inhibiting Hormone (PIH, Dopamine)
82
Just before puberty two gonadotrophins (sex hormones) are secreted in gradually increasing amounts by the anterior pituitary in response to __
Luteinising Hormone Releasing Hormone (LHRH)
83
Luteinising Hormone Releasing Hormone (LHRH) also known as
Gonadotrophin Releasing Hormone (GnRH)
84
Rising levels of these hormones at puberty promotes mature functioning of the reproductive organs
Gonadotrophin (sex hormone)
85
In both males and females the hormones responsible are
- Follicle stimulating hormone (FSH)
- Luteinising Hormone (LH)
86
What hormone?
In female: regulates the development of sex organs in female, development of immature ovarian follicle from the ovary
Secretes oestrogen and progesterone during menstrual cycle
In male: initiation of spermatogenesis
Follicle stimulating hormone (FSH)
87
What hormone?
In female: ovulation, maintaining of corpus luteum and secretion of progesterone
In male: testosterone secretion
Luteinising hormone (LH)
88
It is situated in the neck in front of the larynx and trachea at the level of the 5th , 6th and 7th cervical and 1st thoracic vertebrae
Thyroid gland
89
It is a highly vascular gland that weighs about 25 g and is surrounded by a fibrous capsule
Thyroid gland
90
It resembles a butterfly in shape, consisting of two lobes, one on either side of the thyroid cartilage and upper cartilaginous rings of the trachea
Thyroid gland
91
- the lobes are joined by a narrow isthmus, lying in front of the trachea
- the lobes are roughly cone shaped, about 5 cm long and 3 cm wide
Thyroid gland
92
The arterial blood supply to the gland is through the __
Superior and inferior thyroid arteries
93
This is a branch of the external carotid artery
Superior thyroid artery
94
This is a branch of the subclavian artery
Inferior thyroid artery
95
The venous return is by the ___ , which drain into the ___
Thyroid veins, internal jugular veins
96
The gland is composed of largely ___ formed from ___
Spherical follicles , cuboidal epithelium
97
- These secrete and store colloid, a thick sticky protein material
Thyroid gland
98
Between the follicles are other cells found singly or in small groups:
Parafollicular cells
99
Parafollicular cells also called
C-cells
100
Which secrete then hormone calcitonin
Parafollicular cells (C-cells)
101
This is essential for the formation of the thyroid hormone (thyroxine T4 and triiodothyronine T3)
Iodine
102
This is essential for the formation of the thyroid hormone (thyroxine T4 and triiodothyronine T3)
Iodine
103
The thyroid gland selectively takes up iodine from the blood, a process called
Iodine trapping
104
The release of T3 and T4 into the blood is stimulated by ____ from the anterior pituitary
Thyroid stimulating hormone (TSH)
105
Secretion of TSH (thyroid stimulating hormone) is stimulated by ___ from the hypothalamus
Thyrotrophin Releasing Hormone (TRH)
106
The secretion of TRH (thyrotrophin releasing hormone) is stimulated by
- exercise
- stress
- malnutrition
- low plasma glucose levels
- sleep
107
There are the essential for normal growth and development, especially of the skeleton and nervous system
T3 and T4
108
Most other organs and systems are also influenced by thyroid hormones
T3 and T4
109
Physiological effects of T3 and T4 on the heart, skeletal muscles, skin, digestive and reproductive systems are more evident when there is underactivity or overactivity of the thyroid gland and can be profound in childhood
Function of T3 and T4
110
This hormone is secreted by the parafollicular or C-cells in the thyroid gland
Calcitonin
111
It lowers raised blood calcium (Ca2+) levels
Calcitonin
112
It does this by acting on:
- bone cells promoting their storage of calcium
- kidney tubules inhibiting the reabsorption of calcium
Calcitonin
113
The release of this hormone is stimulated by increased blood calcium levels
Calcitonin
114
There are four small ___ , each weighing around 50g, two embedded in the posterior surface of each lobe of the thyroid gland
Parathyroid glands
115
They are surrounded by fine connective tissue capsules that contain spherical cells arranged in columns with sinusoids containing blood in between them
Parathyroid glands
116
These parathyroid glands secrete __. Secretion is regulated by blood calcium levels
Parathyroid hormone (PTH, PARATHORMONE)
117
This hormone main function is to increase blood calcium levels. This is achieved by increasing the calcium absorption from the small intestine and reabsorption from the renal tubules
Parathyroid hormone (PTH)
118
The paired ___ lie superior to the kidneys enclosed within the renal fascia
Adrenal (suprarenal) glands
119
They are about 4 cm long and 3 cm thick
Adrenal glands
120
They are composed of the outer adrenal cortex and the inner adrenal medulla
Adrenal glands
121
It produces a total of about 40 different hormones which are collectively known as corticosteroids
Adrenal cortex
122
The adrenal cortex produces a total of about 40 different hormones which are collectively known as ___
Corticosteroids
123
The complete loss of __ leads to death within a few days to a week , due to dehydration and electrolyte imbalances
Adrenocorticol hormones
124
The glands are composed of two parts which have different structures and functions; the cortex and the medulla
Adrenal glands
125
The outer part of the adrenal glands
Cortex
126
The inner part of the adrenal glands
Medulla
127
The inner part of the adrenal glands
Medulla
128
It is essential to life but the medulla is not
Adrenal cortex
129
Hormones of the adrenal gland:
(Adrenal cortex)
- Cortisol
- Corticosterone
- Cortisone
- Aldosterone
- Androgens
130
Hormones of the adrenal gland:
(Adrenal medulla)
- Epinephrine
- Nor- epinephrine
131
The adrenal cortex produces three groups of steroid hormones from cholesterol. They are collectively called
Adrenocorticocoids (corticosteroids)
132
The adrenal cortex produces three groups of steroid hormones from cholesterol. They are collectively called adrenocorticocoids (corticosteroids)
The groups are:
- glucocorticoids
- mineralocorticoids
- sex hormones (androgens)
133
It is the main glucocorticoid but small amounts of corticosterone and cortisone are also produced
Cortisol (hydrocortisone)
134
Cortisol is the main glucocorticoid but small amounts of Corticosterone and Cortisone are also produced.
Commonly these are collectively known as __
Steroids
135
They are essential for life, regulating metabolism and responses to stress
Cortisol
Corticosterone
Cortisone
Commonly these are collectively known as steroids
136
It is stimulated by ACTH from the anterior pituitary and the stress
Cortisol
137
Its having a anti-inflammatory action
Glucocorticosteroids
138
The adrenal cortex produces three groups of steroid hormones from cholesterol
The groups are:
1. Glucocorticoids
2. Mineralocorticoids
3. Sex hormones (Androgens)
139
What is the main glucocorticoid?
Cortisol
140
What is the main mineralocorticoid?
Aldosterone
141
It is involved in maintaining water and electrolyte balance. Through a negative feedback system it stimulates the reabsorption of sodium (Na+) by the renal tubules and excretion of potassium (K+) in the urine
Aldosterone
142
__ reabsorption is also accompanied by retention of water and therefore aldosterone is involved in the regulation of blood volume and blood pressure too
Sodium
143
Sodium reabsorption is also accompanied by retention of water and therefore ____ is involved in the regulation of blood volume and blood pressure too
Aldosterone
144
__ regulate aldosterone secretion by the adrenal cortex. When ___ rise, more aldosterone is secreted
Blood potassium levels
145
__ is also stimulates the release of aldosterone
Angiotensin
146
RAAS mean
Renin-angiotensin-aldosterone system
147
When renal blood flow is reduced or blood sodium levels falls, what enzyme is secreted by kidney cells?
Renin
148
Renin converts the plasma protein __ produced by the liver, to angiotensin 1
Angiotensinogen
149
Renin converts the plasma protein angiotensinogen produced by the liver, to ___
Angiotensin 1
150
___ , it formed in small quantities in the lungs, proximal kidney tubules and other tissues, converts angiotensin 1 to angiotensin 2, which stimulates secretion of aldosterone
Angiotensin converting enzyme (ACE)
151
What angiotensin causes vasoconstriction and increases blood pressure closing the negative feedback loop?
Angiotensin 2
152
Secreted by the adrenal cortex are mainly androgens ( male sex hormones ) although the amounts produced are insignificant compared with those secreted by the testes and ovaries in late puberty and adulthood
Sex hormones
153
What is the completely surrounded by the adrenal cortex?
Adrenal Medulla
154
It develops from nervous tissue in the embryo and is part of the sympathetic nervous system
Adrenal medulla
155
When stimulated by extensive sympathetic nerve supply, the glands release the hormones __ and __
Adrenaline (epinephrine) 80%
Noradrenaline (norepinephrine) 20%
156
This is the postganglionic neurotransmitter of the sympathetic division of the autonomic nervous system
Noradrenaline (norepinephrine)
157
__ and some __ are released into the blood from the adrenal medulla during stimulation of the sympathetic nervous system
Adrenaline and noradrenaline
158
__ is classified as both and endocrine organ and an exocrine organ, it will also be discussed again with the digestive system
Pancreas
159
There are three main types of cells in the pancreatic islets
- alpha cells
- beta cells
- delta cells
160
Which secrete glucagon
Alpha cells
161
Which are the most numerous, secrete insulin
Beta cells
162
Which secrete somatostatin (GHRIH)
Delta cells
163
What is the normal blood glucose level?
Between 3.5 and 8 mmol/liter (63 to 144 mg/100 mL)
164
Blood glucose levels are controlled mainly by the opposing actions of insulin and glucagon
- glucagon increases blood glucose levels
- insulin reduces blood glucose levels
165
Its main function is to lower raised blood nutrient levels, not only glucose but also amino acids and fatty acids
Insulin
166
Mechanism by which insulin lowers the blood glucose level:
Acting on cell membranes and stimulating uptake and use of glucose by muscle and connective tissue cells
167
Mechanism by which insulin lowers the blood glucose level:
Increasing conversion of glucose to glycogen ( glycogenesis ), especially in the liver and skeletal muscles
168
Mechanism by which insulin lowers the blood glucose level:
Accelerating uptake of amino acids by cells, and the synthesis of protein
169
Mechanism by which insulin lowers the blood glucose level:
Promoting synthesis of fatty acids and storage of fat in adipose tissue ( lipogenesis )
170
Mechanism by which insulin lowers the blood glucose level:
Decreasing glycogenolysis (breakdown of glycogen into glucose)
171
Glucagon increases blood glucose levels by stimulating:
Conversion of glycogen to glucose in the liver and skeletal muscles (glycogenolysis)
172
Glucagon increases blood glucose levels by stimulating:
Secretion of glucagon is stimulated by low blood glucose levels and exercise, and decreased by somatostatin and insulin
173
This hormone, also produced by the hypothalamus, inhibits the secretion of both insulin and glucagon in addition to inhibiting the secretion of GH from the anterior pituitary
Somatostatin (GHRIH)
174
It is a small body attached to the roof of the third ventricle and is connected to it by a short stalk containing nerves, many of which terminate in the hypothalamus
Pineal gland
175
This is about 10 mm long, reddish brown in color and surrounded by a capsule. The gland tends to atrophy after puberty and may become calcified in later life
Pineal gland
176
Pineal gland secretes
Melatonin
177
Secretes melatonin, which is thought to promote sleepiness and help regulate the body’s biological clock.
In animals that breed during specific seasons, melatonin apparently alters their capacity for reproduction, but it has not been shown to have a similar effect on humans
Pineal gland
178
The ovaries and testes are paired oval organs referred to as
Gonads
179
The ___ are the female gonads, located in the pelvic cavity
Ovaries
180
They secrete estrogens and progesterone, which are responsible for the development and maintenance of female sexual characteristics, as well regulating the female reproductive system
(In conjunction with gonadotropic hormones from the pituitary gland)
Ovaries
181
The ovaries also produce __ , which soften connective tissues in preparation for childbirth
Relaxin
182
The __ are the male gonads, located in the scrotum
Testes
183
They secrete testosterone, which is responsible for male sexual characteristics, and inhibit, which controls sperm production by inhibiting follicle stimulating hormone
Testes
184
Hormones produced by the thymus gland are
Thymosin
185
These hormones promote the proliferation and maturation of T cells (white blood cells which destroy microbes and foreign substances)
Thymosin
186
May also help to retard the aging process
Thymic hormones
187
Local hormones
- Histamine
- Serotonin (5-hydroxytryptamine, 5-HT)
- Prostaglandins (PGs)
188
This is synthesized and stored by mast cells in the tissues and basophils in blood. It is released as part of the inflammatory responses, especially when caused by allergy
Histamine
189
This is present in platelets, in the brain and in the intestinal wall. It causes intestinal secretion and contraction of smooth muscle and its role in homeostasis (blood clotting)
Serotonin
190
It is a neurotransmitter in the CNS and is known to influence mood
Serotonin
191
These are lipid substances found in most tissues. They act on neighboring cells but their actions are short -lived as they are quickly metabolized
Prostaglandins
192
Prostaglandins have potent and wide-ranging physiological effects in:
- the inflammatory response
- potentiating pain
- fever
- regulating blood pressure
- blood clotting
- uterine contractions during labor
193
Hormones of anterior pituitary gland
- Adrenocorticotrophic hormone (ACTH)
- Growth hormone (GH)
- Prolactin
- Thyroid stimulating hormone (TSH)
- Follicle stimulating hormone (FSH)
- Luteinising hormone (LH)
194
Hormones of posterior pituitary gland
- Antidiuretic hormone (ADH)
- Oxytocin
195
Master gland of our body
Pituitary gland
196
T4
Thyroxine
197
T3
Triiodothyronine
198
Secreted during pregnancy to prepare the breasts for lactation after childbirth
Function of Prolactin
199
Which hormone lowers the raised blood calcium level?
Calcitonin
200
Which hormone raise the blood calcium level?
Parathyroid hormone (PTH)
201
Hormones of adrenal cortex
- Cortisol
- Corticosterone
- Cortisone
- Aldosterone
- Androgens
202
Hormones of adrenal medulla
- Epinephrine
- Norepinephrine
203
Function of FSH and LH
Together FSH and LH stimulate the secretion of estrogen and progesterone and the maturation of oocytes in the ovaries and the secretion of testosterone and sperm production in the testes
204
Hormone of thymus gland
Thymosin
205
Hormone of pineal gland
Melatonin
206
Hormone of parathyroid gland
Parathyroid hormone (PTH)
207
Sex hormones of male and female
Androgens
