Biology 112 Exam 4 (Final)

Hormones

Chemical signals secreted by cells or glands which influence the actions of other cells within the body

Predatory response

release of adrenaline

mate presence

release of sex hormones

neurosecretory cells

neurons that secrete hormones

Pituitary gland

regulates growth and produces human growth hormone (hgh)

Pancreas

endocrine organ that regulates blood sugar via negative feedback

Hydrophilic hormones

peptides and amines

Hydrophobic hormones

steroids

hormonal pathway

one gland releases a hormone that triggers a second gland to release a hormone

Releasing hormone

comes from the hypothalamus and is the beginning of the hormone pathway

anterior pituitary

forms from epithelial cells in the roof of the mouthpo

posterior pituitary

forms from the neural tissue at the base of the brain

tropic hormones

hormones that control the release of other hormones

THS

target thyroid (controls metabolism)

FSH

signals gonads for sexual development

LH

signals gonads to produce sex hormones

ACTH

signals adrenal glands to produce cortisol in times of stress

hormones released by the posterior pituitary gland

oxytocin and antidiuretic hormone

parathyroid gland

controls the level of calcium in the blood by signaling bone to be built or broke down

pineal gland

controls circadian rhythms by secreting melatonin

Histamines

paracrines that are released when a cell is damaged

pheromones

chemical signals released by animals to communicate with other members of the species

Force

push or pull on one object by anotherm

muscle fiber

individual muscle cell

thin filament

actin - surrounded by double helix tropomyosin

thick filament

myosin - long arrangement of myosin molecules

z-disk

thin filaments are attached to this protein backbone

sarcomere

contractile unit (area from one z-disk to the next)

motor unit

a motor neuron and all of the myofibers that connect to it

sarcoplasmic reticulum

holds all of the calcium that muscle cells need

antagonist muscles

paired muscles that cause the exact opposite movement of each other when they contract

flexion

muscle contraction that causes a bending movement

extension

muscle contraction that causes a straightening movement

agonists

muscles that contract to provide the main force to move or rotate a bone through its joint

isometric contraction

contraction in which the muscle does not change length

lengthening contraction

occurs when the force applied to the muscle exceeds the force that the muscle produces

twitch

muscle contraction of a specific force

tentanus

long sustained muscle contraction caused by fatigue or depletion of