Week 3 Flashcards
what is the posterior pituitary gland?
- extension of the hypothalamus
- Hormones are synthesised in the hypothalamus and pass down through the axon to the PPG where they are released (oxytocin and vasopressin)
what is the anterior pituitary gland?
controlled by hypophysiotropic hormones. Secretes growth hormone, TSH, ACTH, prolactin, FSH and LH
What is the the overview of secretion from the hypothalamus
where is the thyroid gland?
- sits within the neck at the front of the trachea
What does the thyroid gland do?
- Produces thyroxine and triiodothyronine: these two hormones control the release of TSH by negative feedback
- Thyroid hormones increase metabolism, mitochondrial enzyme activity, development of nervous syste and carbohydrate and lipid metabolism
Describe the thyroid releasing system?
What is cortisol?
a hormone released during stress by the hypothalamus and then APG
what does cortisol do in a non stress situation?
maintain normal blood pressure by responding to epinephrine and norepinephrine, anti-inflammatory functions, maintains metabolic enzymes concentration
What does cortisol do in stressful situations?
- effects metabolism (release of glycerol and fatty acids into blood)
- enhanced vascular reactivity & increases cardio performance
- inhibits information and immune system response
- inhibits non essential functions (reproduction & growth)
Describe the release of cortisol system
How does cortisol help with recovery
cortisol inhibits immune system, inhibits inflammatory response and decreases capillary permeability in injured areas which supports recovery
What is the stress trigger response?
- sympathetic nervous system is activated
- epinephrine is released :
Faster breakdown of fuel stores
Larger increase in cardiac function
Bigger increase in ventilation
Give examples of growth hormones?
insulin, growth hormone, T3, and testosterone & estradiol
What is growth hormone?
acts directly onto cells, stimulates protein synthesis and is highest in adolescence. Stimulus of post natal growth & Secreted by anterior pituitary gland
What is testosterone?
Testosterone: promotes muscle growth & development of male sex characteristics. produced by testes
what is oestrogen and progesterone?
promotes female sex characteristic development, regulates menstrual cycle, promotes endothelial function and adipose tissue growth. Secreted by ovaries
Describe the secretion of human growth hormones system?
Describe the sex hormones secreted system?
What are the oestrogen protective affects?
Without ostrogen the body is at greater risk
- During menopause ostrogen decreases which leads to large artery stiffening and endothelial dysfunction which can increase risk of CVD and CBVD.
what is the order of cells in muscle
muscle
fascicles
muscle fibres
myofibrils
sarcomere
Describe the motor unit step by step?
what is the excitation-contraction coupling?
When the action potential activates the force generating mechanisms by the electrical stimulus being converted to a mechanical response. Ca2+ provides the link
How does calcium affect relaxed muscle and active muscle?
Relaxed Muscle- low Ca2+ so cross bridges cannot bind with actin because tropomyosin is covering binding site
Active Muscle- high Ca2+ so cross bridges form between actin and myosin because Ca2+ binds to troponin moving tropomyosin away
What is the action potential propagation?
The process by which action potentials spread along the axon
