<< Chapter < Page Chapter >> Page >

Generally as little as 30 minutes of noncontinuous exercise over the course of each day has beneficial effects and has been shown to lower the rate of heart attack by nearly 50 percent. While it is always advisable to follow a healthy diet, stop smoking, and lose weight, studies have clearly shown that fit, overweight people may actually be healthier overall than sedentary slender people. Thus, the benefits of moderate exercise are undeniable.

Clinical considerations in vascular homeostasis

Any disorder that affects blood volume, vascular tone, or any other aspect of vascular functioning is likely to affect vascular homeostasis as well. That includes hypertension, hemorrhage, and shock.

Hypertension and hypotension

Chronically elevated blood pressure is known clinically as hypertension    . It is defined as chronic and persistent blood pressure measurements of 140/90 mm Hg or above. Pressures between 120/80 and 140/90 mm Hg are defined as prehypertension. About 68 million Americans currently suffer from hypertension. Unfortunately, hypertension is typically a silent disorder; therefore, hypertensive patients may fail to recognize the seriousness of their condition and fail to follow their treatment plan. The result is often a heart attack or stroke. Hypertension may also lead to an aneurism (ballooning of a blood vessel caused by a weakening of the wall), peripheral arterial disease (obstruction of vessels in peripheral regions of the body), chronic kidney disease, or heart failure.

Listen to this CDC podcast to learn about hypertension, often described as a “silent killer.” What steps can you take to reduce your risk of a heart attack or stroke?

Hemorrhage

Minor blood loss is managed by hemostasis and repair. Hemorrhage is a loss of blood that cannot be controlled by hemostatic mechanisms. Initially, the body responds to hemorrhage by initiating mechanisms aimed at increasing blood pressure and maintaining blood flow. Ultimately, however, blood volume will need to be restored, either through physiological processes or through medical intervention.

In response to blood loss, stimuli from the baroreceptors trigger the cardiovascular centers to stimulate sympathetic responses to increase cardiac output and vasoconstriction. This typically prompts the heart rate to increase to about 180–200 contractions per minute, restoring cardiac output to normal levels. Vasoconstriction of the arterioles increases vascular resistance, whereas constriction of the veins increases venous return to the heart. Both of these steps will help increase blood pressure. Sympathetic stimulation also triggers the release of epinephrine and norepinephrine, which enhance both cardiac output and vasoconstriction. If blood loss were less than 20 percent of total blood volume, these responses together would usually return blood pressure to normal and redirect the remaining blood to the tissues.

Additional endocrine involvement is necessary, however, to restore the lost blood volume. The angiotensin-renin-aldosterone mechanism stimulates the thirst center in the hypothalamus, which increases fluid consumption to help restore the lost blood. More importantly, it increases renal reabsorption of sodium and water, reducing water loss in urine output. The kidneys also increase the production of EPO, stimulating the formation of erythrocytes that not only deliver oxygen to the tissues but also increase overall blood volume. [link] summarizes the responses to loss of blood volume.

Questions & Answers

what is normal flora
Cris Reply
the smallest blood vessel is capillary
Richard Reply
How does deoxygenated blood become oxygenated during blood circulation?
Richard
plzzz explain cardiac cycle
Piya Reply
what is anatomy
Gifty Reply
is the study of body structure
Amos
how types of tissue in body
mwiya
What are some of first questions are expected in anatomy and physiology course
Milner Reply
what is pacemaker
mekfira
its a device that is put into the heart to make sure it beats properly
Michelle
SA node produces impulse is called pacemaker
Piya
hi piya
Khubaib
hi Everyone
Hayat
hi everyone
Hong
hey
Edrick
hello
Damien
what's up
Damien
hlo
Lost
hi
Bok
hello
James
hi
IDDRISU
which of the following is the epithelial tissue that lines the interior of blood vessels?
Firomsa Reply
endothelial tissues
Osaki
Endothelial tissue
mabast
why are the questions only 3
Chisom Reply
you too can ask
Addo
what is the function of the skeletal system?
Cris
what is the treatment of herpes simplex virus?
riad Reply
the long bone with two primary center's of ossification for shaft is ________
Aarambam
medulla
Addo
good
Ravi
ha moj ha
Hani
doctor and nurse
Ravi
y 're the questions only 3
Chisom
women are much likely to be pregnant at which stage?
Fatoumatta Reply
There are only six days during any cycle when a woman can get pregnant - the five days leading up to ovulation and the 24 hours after ovulation. This is because sperm can live for up to 5 days in a woman's body, and the ovum lives for only 12-24 hours.
THE
right
Adil
does this apply to women close to menopose
Kuria
what's reason the reason for BP growing ?
Adil
when after they have intercourse
AJ
what is andropause
William Reply
It's the men version of menopause!
Catia
The testosterone levels decrease
Catia
what would happen if the sugar lever drops below the normal level
Marvin Reply
If our blood sugar drops below 70 mg/dL, we may have symptoms, such as feeling tired, weak, or shaky, become confused or drowsy or even lose consciousness and possibly die.
Dhanya
symptoms of hypoglycemia include: shakiness, dizziness, headache, confusion, rapid pulse rate, sweating, Hunger, etc.
EMERIBE
you right
Khubaib
You become dizzy and weak
evans
Is there any way to disable this chat feature or at least mute notifications? Also, does every textbook app from this creator have the chat function?
Atone Reply
I don't think you can disable chat and yes it is on every app
AJ
what is homeostasis
Nikky Reply
what is respiratory
Nikky
Respiratory is breathing
Atone
respiration is an exchange of gases (O2 & CO2) between the body and outside environment.
joey
homeostasis is internal balance.
Ali
Respiratory is system where the body takes in oxygen n releases carbondioxide
Hassan
respiratory system is a system where exhalation and inhalation takes place
Kom
1)inhalation: active diaphragm & external intercoastal muscles 2)exhalation: passive (allow muscle group to relax)
Shoukat
mantaince of body is called homeostasis
Komal
hi komal
Khubaib
how are you komal?
Khubaib
hi
Komal
hey nikki
Khubaib
hii komal
Rinku
where you from kamal?
Khubaib
nice meet you
Rinku
oye rinku kya ha yahan kya kar rha ha
Khubaib
karachi
Komal
but I'm from lahore
Khubaib
friendship ho jay? komal
Khubaib
never
Komal
0309
Khubaib
khubaib arooj tu aa sakta h to me q nhi aa sakta
Rinku
4291248
Khubaib
waw komal
Rinku
where you from?rinku
Khubaib
what is medical coding
Antony
waw komal
Rinku
yar rinku kahan se ho ap
Khubaib
I am from dausa,Rajasthan
Rinku
yar hum to pakistan se hain humy baat karny do
Khubaib
hoe r u alll
SARFARAJ
komal jha?
Khubaib
answer me please...What is basic concept or Acidosis?
Khalid
hiii komal
SARFARAJ
al hamd.o.lillah muslim
Khubaib
or aap
Khubaib
Allah ka shukr ha
SARFARAJ
aby tu b india chala ja un ko zarorat ha foji logon ki
Khubaib
beshak
Khubaib
myself Khalid Shabbir.Doctor of Anesthesia from PIMS Hospital.& belongs to Capital IslamAbad(Pakistan).
Khalid
yar sarfraz ap india se kab ay
Khubaib
tell me abt ethmoid bone
Sakshi
bro am all ready indian
SARFARAJ
okkk
SARFARAJ
hii sakshi how are you?
Khubaib
m gd..plz tell me the answer of it..
Sakshi
Face ki he ethmoid bone
Rakesh
ethmoid bone. Irregularly shaped bone anterior to the solenoid. Forms the roof of the nasal cavity, upper nasal septum, and part of the medial orbit walls.
LaKecia
Its unpaired bone of skull that saprate the nasal cavity from the brain it's located at the roof of the nose between the two orbits it's bone is one of the bones that make up the orbit of eye.
SARFARAJ
sphenoid I meant
LaKecia
wrist joint ka dusra name kya he
Rakesh
till me fast my ans
Rakesh
Also included in the ethmoid bone is the crista galli and the cribriform plates. The plates help form the roof of the nasal cavity and the floor of the anterior cranial fossa.
LaKecia
the outer most covering of the brain ( the dura mater) attached to the crista galli and helps secure the brain in the cranial cavity
LaKecia
Sakshi Mishra. I hope that helped!
LaKecia
thnks fo tellng😊
Sakshi
yup
Sakshi
yw
LaKecia
ye kya
Dr
hi
Dr
oh welcome sakshi
Khubaib
synovial joint will have present in wrist
sk
what's the smallest blood vessal in the body?
sk
respiration is the process of inspiration an expiration
Bel
first fall give me ans plz
sk
The protection of internal envirnment from the harm of external envirnmen is called as homeostasis.
Rana
Because stem cells have the unique ability to develop into any cell, stem cell therapy is being considered for treatment of kidney damage. What are your thoughts on stem cell treatment? Give at least three reasons for or against the treatment.
Samira Reply
to know the structure of the human body. to study the region of the human body. to understand the circulation of blood in the human body.
Angelashimakela Reply

Get the best Anatomy & Physiology course in your pocket!





Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Anatomy & Physiology' conversation and receive update notifications?

Ask