类别 全部 - endocrine

作者:NA - 11MM 972639 Stephen Lewis SS 2 年以前

109

Endocrine system

The body's response to changes in temperature involves various systems working together to maintain homeostasis. Thermoreceptors detect increased body temperature and signal the hypothalamus, which activates cooling mechanisms like dilation of skin blood vessels and sweating, leading to a decrease in temperature.

Endocrine system

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body temperature

when high

Sensor: thermoreceptors signal an increase in temperature
Integrator

Hypothalamus turns on cooling systems

Effector: Skin blood vessels dilate; increased blood flow to skin; thermal energy loss from skin

Result

Body temperature decreases; hypothalamus turns off cooling systems

Effector: sweat glands initiate sweating; evaporation of swear causes cooling

Endocrine system

Such as

decrease in fat

Lowering of voice

increase in muscle

Producess

Testosterone

Sperm cells

Puberty, LH

Inhibits production of FSH

Hypothalamus

Inhibin

Male development

Puberty, FSH

Secondary sex characteristics

widening of the hips

growth of body hair

increase in body fat

breast development

Inhibits FSH production

Increases LH production,

Thickening of uterus

Many cells

Uterus, hypothalamus

Estrogen

Inhibits LH production

Preventing development of other follicles

Progesterone hormone

Contain

Group of cells

Called

develop

during each cycle

only one reaches maturity

at puberty

400000

Granulosa cells

Primary oocyte

Contributes to

female development

Adrenal Glands
Adrenal medulla

glycogen break down

dilation of pupils

blood flow

heart

breathing rate

HR

lungs

Blood vessels

Heart

Noradrenaline

Adrenaline

Adrenal cortex

Aldosterone

Increasing Na absorptio

in both

higher blood pressure

colon

Colon

Cortisol

include

decreasing

permeability of capillaries

affected tissues

Break down of muscle and fat

to increase

available energy

Target Tissues

Capillaries

Adipose tissue

Muscles

Thymus gland

Maturing T cells

Immune system

Thymosin

the

Body feedback

when

T cells are needed

Includes the

Pineal Gland

Making you sleepy

only if

in the dark

lack of it

making you awake (in light)

Brain

Melatonin

darkness

Circadian rhythm

Pancreas

High glucose levels

Uptake of glucose

to be

stored as glycogen

Target Tissue

Liver and muscle cells

Low glucose levels

Effects

release of glucose

Breakdown of glycogen

includes the

Hypothalamus gland

Pituitary gland

Nervous system

Release inhibiting hormones

Stops the release

of

anterior pituitary hormones

Releasing hormones

Release of anterior pituitary hormones

neurohormones

Made by

neurons

Regulates

Pituitary gland activities

neurosecretory cells

feedback loop

maintain homeostasis

blood glucose levels

if low

Removal of excess glucose from blood

Low blood glucose level

Alpha cells of pancreas stimulated to release glucagon into the blood

Glucagon

Liver breaks down glycogen and releases glucose to the blood

Blood glucose level rises to set point; stimulus for glucagon release diminishes

if high

Stimulus is

Rising blood glucose level

Beta cells of pancreas stimulated to release insulin into the blood

Insulin

Body cells take up more glucose

Blood glucose level declines to a set point; stimulus for insulin release diminishes

Liver takes up glucose and stores it as glycogen

disorders

Diabetes

Insulin injections

should be balanced

with

meals

doesn't prevent

serious complications

blindness

stroke

useful for

Monitor blood sugar

regulating blood sugar

has

3 types

Gestational diabetes

occurs in

2-4% of pregnancies

Temporary condition

Type 2 diabetes

Non-Insulin dependent

Controlled with

sulfonamide drugs

stimulate

islets of langerhans

exercise

diet

Decreased

insulin production

or

ineffective use of insulin

adulthood

Type 1 diabetes

Insulin dependent

Unable to

produce insulin

Diagnosed in

childhood

Early degeneration of beta cells

Increase HGH

Acromegaly

thickness of bones

feet

hands

face

Young

Gigantism

results in

growth of long bones

Decrease HGH

happens

When old

HGH naturally decrease

decrease protein synthesis

maybe the reason

decreasing muscle mass

When young

late or no puberty

leads

pituitary dwarfism

being

small

normal proportion

Vitamin D deficiency

takes place

Adult

Osteomalacia

Soft bones

Infant

causing

Rickets

Impairs normal growth

increase Fractures

Skeletal deformities

Hypothyroidism

is using

thyroxine supplements

for example

Decrease in

HR and output

Increase weight gain

but

unable to make thyroxine

thyroid is stimulated

divide/grow

can cause

goiter

iodine deficiency

Decrease

Hyperthyroidism

Treatment

radioactive iodine

to

destroy affected tissue

thyroid blocking drugs

remove thyroid

including

bulging eyes

increase in

sweating

heat

appetite

weight loss

BMR

muscle weakness

Autoimmune disorder

attacks

TSH receptors on thyroid cells

making them

permanently on

leading

produce thyroxine

thyroid cells to continuously divide

increases

thyroxine

Addison disease

Loss of appetite

Weight loss

Low blood pressure

adrenocortical insufficiency

dysfunction of the entire adrenal cortex

hypoadrenocorticism

Cushing’s syndrome

Symptoms

Fluid retention

Muscle weakness

High blood glucose

High blood pressure

a hormonal disorder

caused by

prolonged exposure of the body’s tissue to high levels of cortisol.

known as

hypercortisolism

if it isn't healthy

lack energy

due to

too much sugar staying in the blood

instead of

moving into your cells

where

needed for energy

weak bones
gaining weight easily
problems

managing stress

getting pregnant

developing during puberty

Functions

Control the process of sexual reproduction

nourishment of the newborn

fetal growth and development

fertilization

gametogenesis

Regulation of growth and development
maintaining homeostasis

an interaction between

both

nervous system

endocrine system

Monitors

Consists of

several organs

glands

Create & secrete

Are

chemicals

have

two types

Protein hormones

Growth factors

Consist of

amino acids chains

length ranges

3 a.a to more than 200 a.a

receptors on cell surface

Hydrophilic

meaning

water soluble

cannot enter plasma membrane of target cells

Not lipid soluble

Steroid hormones

Example

sex hormones

Bind to

receptors inside target cell

made from

cholesterol

Hydrophobic

can

pass through lipid bilayer

is not

soluble in blood

thus

combine with a hydrophilic protein carrier

to move

through the blood

Lipid soluble

controlled by

Antagonistic hormones

opposing actions

Feedback loops

usually

negative

Released into the blood

affect

cells in another part of the body.

coordinates

different functions in the body

by

carrying messages through the blood

to the

skin

organs

Notify

the body what to do and when to do it

Located

Throughout the body

Glands in Skin/Kidneys

releasing

Ca from bones into blood

leading to

increase [Ca] in the blood

increase of Ca re-absorption in kidneys

Ca absorption in the SI

bones

Small intestine

makes

Vitamin D

which Stimulus

Sun - UV radiation of cholesterol

found in

cell membranes

Anterior Pituitary
Produces

hormones

such as

Endorphins

Influence

pain receptors

brain

MSH

Effect

appetite suppression in humans

there isn't

clear details yet

causes

darkening of skin

reptiles

amphibians

by increasing

production of the dark pigment melanin

called

melanocytes

fish

LH

Ovaries

follicle

produces progesterone

release ovum

Produce estrogen

Producing testosterone

FSH

Follicles

located in

ovaries

Females

secretion of sex hormones

stimulates egg growth and developmen

Release estrogen

Testes

in

Males

Stimulating sperm production

ACTH

Adrenal gland

know as

cortex

producing or releasing

aldosterone

cortisol

HGH

muscles

cartilage

effects are

tissue growth

protein synthesis

calcium absorption

Bones

PRL

milk production

Stimulating breast development

TSH

target gland

Thyroid gland

Production and release of thyroxine

releasing and inhibiting hormones

from

Includes

Posterior Pituitary

are

High [Na] in blood

ADH

target tissue

Kidneys

to prevent

dehydration

increasing

water reabsorption

Suckling

Pressure on opening of uterus

Oxytocin

produced in

hypothalamus

stimulated to

release by

Nursing

during

breast feeding

Labour

is

a positive feedback loop

as

head of fetus pushes against cervix

Nerve impulses from cervix transmitted to brain

Brain stimulates pituitary gland to secrete oxytocin

oxytocin carried in bloodstream to uterus

oxytocin stimulates uterine concentration and pushes fetus toward cervix

target tissues

Mammary glands

Releasing

milk

Uterus

effect

Contraction

which

stores and releases

includes

Parathyroid gland
effects

[Ca] reabsorbed by kidneys

[Ca] released by bones

Parathyroid hormone

[Ca] in blood is too low

Subtopic

Thyroid Gland
produces

Calcitonin

kidneys

Bone

effect is

[Ca] taken up by bones

then

excreted by kidneys

triiodothyronine

Thyroxine

effect by

Increasing metabolism

leads to

Shutting down TSH production

targets

Most cells in body

Stimulus

Need for energy

Maintain homeostasis

rising blood Ca levels

Thyroid gland releases calcitonin

calcitonin

Reduces Ca^2+ uptake in kidneys

Stimulates Ca^2+ deposition in bones

Blood Ca^2+ level declines to set point