BIO 424 Exam 1,Exam 2 and Exam 3 All

BIO 424 Exam 1,Exam 2 and Exam 3 All Together Latest Update 2023-2024 510 Questions and Verified Correct Answers Guaranteed Success -tocins - Correct Answer: neural peptides that possess muscle contracting and milk ejecting activity in mammals

[Ca] in body - Correct Answer: total plasma calcium (2.5 mM) exists in blood plasma

as:

• nondiffusable (protein bound, albumin) Ca - 1.16 mM
• diffusible (ionized or free Ca) - 1.34mM

is it the free Ca component that is important in physiological processes and is tightly regulated

99% in bone and teeth 1% as intracellular Ca 0.1% as extracellular and plasma Ca

2 common ways male pseudohermaphrodism occurs - Correct Answer: androgen

insensitivity syndrome/testicular feminization

5alpha-reductase deficiency

3 basic things needed to measure hormone in tissue or blood - Correct Answer:

require a purified antigen (hormone) specific antibody to the antigen labelled antigen or hormone

• components of

mammalian sex determination/differentiation - Correct Answer: chromosomal sex

gonad sex phenotypic or anatomic sex

• factors that affect hormone activity - Correct Answer: plasma levels of hormone,

clearance rate, receptor abundance

• levels of insulin resistance - Correct Answer: prereceptor insulin resistance
• antibodies against insulin, mutant insulin structure causing impaired binding of insulin

to receptor

receptor resistance

• reduced receptor number, impaired signaling, antibodies produced to receptor
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postrecepetor insulin resistance

• under-expression of pancreatic beta-cell glucose transporters and hence reduced

ability to respond to glucose.-auto-antibodies to GLUT2 transporters in beta-cells

3 stages of stress response - Correct Answer: initial alarm reaction

resistance

exhaustion

5 melanocortin receptors - Correct Answer: 1 - MSH

2 - ACTH

3-5 - orphan though will bind melanocortins and synthetic analogs

5alpha-reductase deficiency - Correct Answer: individual has testes, as well as a blind vaginal pouch and labia, but with a small penis (hypospadic) capable of ejaculation instead of clitoris

no mullerian structures are present

wolffian ducts are stabalized so that epididymis, vas deferens, and seminal vesicle are well differentiated

normally raised as girls

testes descend at puberty, voices deepen, and often develop male sexual identity

A/B domain - Correct Answer: N-terminal or regulatory domain

most variable among steroid receptors

has transcriptional activation sites or activation function (AF-1) where it interacts with other components of transcriptional machinery to regulate gene transcription

ACTH diseases - Correct Answer: hypersecretion leads to Cushing's - hyperglycemia, central obesity, hypertension, glucose resistance, DM, osteoporosis, hirsutism (facial hair)

hyposecretion leads to Addison's - fatigue, muscle weakness, weight loss

Action of aldosterone - Correct Answer: Na absorption - distal tubule of kidney

• increases blood Na concentration - Na is actively transported across tubular serosal

membrane into the peritubular space

• decreases blood K and H concentration - passively shunted across the mucosal

membrane in exchange for Na 2 / 4

Water absorption - passively reabsorbed

• increases blood volume
• follows Na reabsorption

Action of GH - Correct Answer: Most actions are indirect and mediated by insulin-like growth factor-I (IGF-I)

• METABOLIC actions are DIRECT

Stimulates skeletal and tissue growth, chondrogenesis at epiphyseal plate

Promotes production of energy stores or macromolecules (anabolic) and incorporates aa into muscle protein

Stimulates lipolysis

diabetogenic - causes high blood glucose; tissues become resistant to insulin

promotes osmoregularity hormone in fish moving TO saltwater

-parr-smolt: FW-SW in salmonids

Action of glucocorticoid - Correct Answer: gluconeogenic

• process resulting in more plasma glucose
• glucocorticoids are hyperglycemic hormones - result in excess plasma glucose which

is opposite of what insulin does

• glucocorticoids are fight-or-flight hormones - need lots of energy (glucose) if you're

going to run or fight

• cortisol is a catabolic hormone - reduces energy stores in muscle and fat tissues

anti-inflammatory

• supraphysiological concentration of cortisol (higher than normal physiological levels)

decrease leukocyte migration, stabilizes lysozomes

• synthetic glucocorticoids (e.g. decamethasone, prednisolone) are used to treat

infection, skin rashes, allergic reactions, joint pain

lowers immunity (immunosuppressive)

• too much cortisol results in reduction of immunity
• destroys antibodies and lymphocytes
• we get sick from prolonged stress
• important not to treat infections/inflammations with excessive glucocorticoids because

it

lactogenic

• required along with PRL for inducing production of genes (e.g. ca
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Action of MSH - Correct Answer: stimulates pigmentation by its effects on melanocytes and dispersal of melanin

• melanocortins, MSHs, and ACTH (in humans, peptide sequence contains MSH and

can cause pigmentation) are found in the brain and skin and may also regulate skin pigmentation

stimulates dispersion of melanin and other pigments

• if not released than melanosome pigment is concentrated

Action of prolactin - Correct Answer: Salt and water balance

-PRL is Na-retaining hormone to conserve water in freshwater environment

growth and development reproduction and behavior actions on the integument actions on steroid-dependent tissues or synergism with steroids mammary gland growth and development in mammals

milk-production in mammary glands

maintenance of pregnancy (maintenance of corpus luteum)

mucous production in discus fish - discus milk for young

production of crop sac milk in birds birds develop brood patch that they use for mating

increases tadpole growth and is anti-metamorphic in amphibians (halts transformation to allows for growth)

stimulates water drive in amphibians; newts move into water to reproduce

nesting and maternal behavior in fish and birds

skin sloughing and tail regeneration in reptiles

actions of androgens - Correct Answer: sexual maturation

development of sperm

• occurs via T which acts in concert with androgen binding protein

growth and maturation of male secondary sexual characteristics

• hair, vocal cords
• antlers, beaks, ,claws, spines (specialized integument sexually diimorphic)
• occurs via DHT
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