list the six functional groups of chemical messenger
Paracrine
Autocrines
Cytokines
neurotransmitters
hormones
neurohormones
describe paracrine
made locally and act on adjancet cells (same tissue organ) they are tranmitted via extracellular fluid.
Describe autocrine
Hormone produced and exerted effects on the same cell- secretory and target cell are the same.
Describe cytokine
(immunohormones) produced by non-gland cells play a key role in the immune system. they travel through the plood into target cell.
Describe neurotransmitters
Used only by nerves to transmit signals they are between two neurons or with a target cell. Adrenaline can also be a neurotransmitter
Describe hormones
Secreted from specialised glands, they are transported via the circulatory system, these can travel long distances around the body. There are two types, a free monroe or a bound to carrier protein.
describe neuro horomones
Secreted by neurosecretory cells (posterior pituitary). The neuron is the secreting cell, it responds to an electrical signal which when received it will release a neurohormone into the blood, this hormone travels to the target cell, they differ from normal neurons, they are over short distances.
list the five diffferent chemical structure categories of chemical messenger
Steroids
Eicosanoids
Amino acids
Protiens and peptides
Amino acids
Descibe amino acid derivates as chemical messangers
systhesis in cyotosol, they can be pracrines, neurotransmitters or hormones
- hydrophobic / lipophillic (mostly)
Describe steroids as chemical messangers
derived from lipd they are crucial for storage, transport, and sginal release and trasmission
- hydrophobic / lipophilic
describe Eiscosanoids as chemical messangers
dervied from lipids, sythesised on demand from membrane phospholipids, they are often used in inflamiation
- hyrodphobic / lipophobic
Describe protein and peptides as chemical messangers
made from short polypeptides or glycoproteins and small proteins. they bind to transmembrane receptors.
- hyrodophilic / lipophobic
describe amino acids as chemical messangers
there are four amino acids that re chemical messengers, all are neuro tranmitters for the CNS.
what is the importance of the hydrophobicity/hydrophilicity of a chemical messenger
Hydrophobicity/ hydrophilicity influences transport, signal production, synthesis, storage and release. These are determined by the chemical structure of the hormone.
Describe the role of receptors in cell to cell communication
Cell receptors are specialised proteins to receive specific messengers (ligans), these are only for indirect communication.
define primary and secondary endocrine organs (giving examples for each)
Primary - organs which primary function is producing hormones or the endocrine system (pituitary gland, thyroid gland, gonads, pancreas and adrenal cortex)
Secondary - organs which are a part of the endocrine system however have other functions as well. (liver, Pineal, Skin, Kidney, Hypothalamus ect)
Explain the difference between exocrine and endocrine glands
Exocrine glands - Releases substances into an external environment (tears, salivary, nipples, digestive, sweat ect.)
Endocrine glands - release substances into capillary beds attached to the gland (inside body) (pituitary gland, thyroid, Adrenal gland, ect)
Explain the role of the hypothalamus and pituitary, and how the hypothalamus is functionally and structurally connected to both parts of the pituitary
The hypothalamus is the central control of hormone secretion as it is the homeostatic feedback creator, it is directly connected by a stalk to the anterior and posterior pituitary glands.
which pituitary gland in connected through nerves directly to the hypothalamus.
The posterior gland is connected via nerves, this provides a fast feedback loop.
list horomnes secreted by the posterior pituitary gland
oxytocin
Antidiuretic hormone (ADH)
list horomnes secreted by the anterior pitutitary gland
Prolactin
Growth hormone
Follicle stimulating hormone (FSH)
Luteinizing hormone (LH)
Thyroid stimulating hormone (TSH)
Melanocyte Stimulating hormone (MSH)
Adrenocorticotropic Hormone (ACTH)
how is the anterior pituitary gland connnected to the hypothalamus
capillary beds that give feedback to the hypothalamus.
describe the effect of prolactin
secretion of milk
describe the effect of growth hormone
grows the muscle or bone
