Endocrine system Flashcards
Components:
Host gland
Hormone
Target organ/tissue
Endocrine system functions
- Internal environment maintence
- Growth and development
- Sexual reproduction and development (control, maintenance and instigation)
Hormone functions
- Enzyme systems
- Cellular activation
- Stimulate protein synthesis
- Muscular contraction and relaxation
2 hormone classifications
- Steroid (lipid soluble and diffuse through cell membrane) - insulin
- Non-steroid (non-lipid soluble and received by receptors outside of cell) - glucose
Anterior pituitary gland direct effects (master gland)
- Secretes hormones that regulate other glands
Growth hormone
Secreted by anterior pituiary gland through GHRH
- Promotes bone growth
- Increases muscle mass due to increased protein synthesis
Negative feedback
System by the body to bring body back to homeostasis, e.g. when hot, we seat and when cold we shiver to ensure correct temperature
Hormone level control adrenal gland
Neural, hormonal and humoral control
Glands may secrete multiple hormones BUT…
Usually single cells in the gland typically secrete one specific hormone (exceptions of LH and FSH)
Gonadotropins in the anterior pituitary
Release Luteinizing hormone and follicle stimulating hormone (FSH) from the same cells
Follicular phase
- Increased muscular strength and endurance
- Improved cardiovascular function
- Higher pain tolerance
- Faster recovery
- Better mood and motivation
Hypothalamus
- Bridge between nervous and endocrine system
- Produces RELEASING and INHIBITING hormones that control the pituitary gland
Name all of the hormone secreting glands
- Pituitary
- Thyroid
- Parathyroid
- Testes/ovaries
- Adrenal
- Pancreas
Name the other tissues that secrete hormones
- Hypothalamus
- GI tract
- Liver
- Heart
- Kidneys
- Placenta
- Adipose tissues
How do women typically feel during the follicular phase?
- Increased muscle strength and endurance
- Improved cardiovascular function
- Higher pain tolerance
- Faster recovery
- Better mood and motivation
What are the 4 phases of the menstrual cycle?
- Menstrual - Day 1-5
- Follicular - Day 1-13
- Luteal - Day 14
- Ovulation - Day 15-28
Menstrual phase
Days 1-5
Shedding of the uterine lining (period)
Follicular phase
Days 1-13
Follicles in the ovary mature and oestrogen levels rise
Ovulation
Day 14
Egg is released from the ovary
Luteal phase
Body prepares for pregnancy
Progesterone levels rise
When does FSH levels rise and what do they do in the menstrual cycle?
Levels rise slightly between the menstrual phase then fall neutral, then spike just after ovulation and then fall neutral again
- Stimulates growth of ovary follicles during the follicular phase
When does LH levels rise and what do they do in the menstrual cycle?
Massive spike just after ovulation then rapidly fall back to neutral again
- Triggers ovulation so mature egg is released
When does oestrogen levels rise and what do they do in the menstrual cycle?
Oestrogen has a small rise at the end of the menstrual phase and then has a relatively sharp increase just after ovulation, with a sharp fall in the luteal phase
- Helps rebuild uterine lining and stimulates for the release of LH
When does progesterone levels rise and what do they do in the menstrual cycle?
Have a relatively sharp spike in the middle of the luteal phase (roughly day 21) then have a relatively sharp spike back down
- Prepares body for possible pregnancy
