Docsity
Log inSign up
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search Store documents

The best documents sold by students who completed their studies

Search through all study resources
Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

From our blog

Exams and Study
Go to the blog

Homeostasis Notes Human Anatomy and Physiology, Lecture notes of Anatomy

Babu Banarasi Das UniversityAnatomy

Homeostasis Notes Human Anatomy and Physiology

Typology: Lecture notes

2021/2022

Available from 01/05/2023

Dr_Raihan
Dr_Raihan 🇮🇳

16 documents

1 / 11

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Homeostasis
Objectives
At the end of this lecture, students will be able to –
• Explain Homeostasis
• Describe the importance of homeostasis
• Explain role of different organ systems in maintaining body’s environment
• List out components of homeostasis system
• Explain mechanism involved in the internal environment maintenance
• Describe feedback loop
Content
• Homeostasis
• Different organ and organ system involved in the maintenance of body’s internal environment
• Functioning of various organ system in homeostasis
• Components involved in homeostasis
• Mechanism involved in the Homeostasis
• Positive feedback mechanism
• Negative feedback mechanism
LIFE’S BALANCING ACT
• If you are too hot or too cold your body temeruture is out of balance.
• When we are too cold we shiver, it warms us up
• When we are too hot we sweat, it cools us down.
www.pharmanotes.org
Page 1 of 11
pf3
pf4
pf5
pf8
pf9
pfa

Partial preview of the text

Download Homeostasis Notes Human Anatomy and Physiology and more Lecture notes Anatomy in PDF only on Docsity!

Homeostasis

Objectives

At the end of this lecture, students will be able to –

  • Explain Homeostasis
  • Describe the importance of homeostasis
  • Explain role of different organ systems in maintaining body’s environment
  • List out components of homeostasis system
  • Explain mechanism involved in the internal environment maintenance
  • Describe feedback loop

Content

  • Homeostasis
  • Different organ and organ system involved in the maintenance of body’s internal environment
  • Functioning of various organ system in homeostasis
  • Components involved in homeostasis
  • Mechanism involved in the Homeostasis
  • Positive feedback mechanism
  • Negative feedback mechanism

LIFE’S BALANCING ACT

  • If you are too hot or too cold your body temeruture is out of balance.
  • When we are too cold we shiver, it warms us up
  • When we are too hot we sweat, it cools us down.

Homeostasis

  • Greek words; Homeo = ‘unchanging’ and Stasis = ‘standing’
  • In its simplest form it means ‘staying the same’
  • It is an organism’s internal environment which ‘stays the same’
  • So, a better definition of ‘homeostasis’ is the maintenance of the internal environment within narrow limits
  • In practice, it comes down to providing a stable environment for the cells of the body
  • The living processes in the cells depend on the activity of enzymes.
  • These enzymes work best in specific conditions such as those of temperature and pH.
  • Any change in these conditions affects the function of the enzymes and may lead to the death of the cells or, ultimately, the whole organism
  • Internal conditions are not absolutely constant, but allowed to vary within very narrow limits. Ex: Human body temperature varies between 36.1 – 37.8 o C. The average temperature is usually expressed as 36.8o C
  • There is no specific organ which controls homeostasis except, possibly, the brain
  • The skin, kidneys, liver, endocrine system, nervous system and sensory system all play a part in maintaining the internal environment within narrow limits

ALL ORGANS AND ORGAN SYSTEMS OF THE BODY HELP IN MAINTENANCE OF

HOMEOSTASIS

  • Cardiovascular system.
  • Respiratory system.
  • Nervous system.
  • Endocrine system.
  • Gastrointestinal system.
  • Excretory system.
  • Skeletal system.
  • Integumentary system.
  • Reproductive system. CARDIOVASCULAR SYSTEM
  • Transports oxygen, carbon dioxide, nutrients and hormones to and from the body cells.
  • Helps regulate pH and temperature.
  • Provides protection against diseases.
  • Regulates the activity and growth of target cells in the body.
  • Regulate metabolism
  • The glucose concentration in the blood is controlled by the pancreas
  • The pancreas contains cells which produce digestive enzymes but it also contains cells (alpha and beta cells) which produce the hormones insulin and glucagon
  • If the glucose concentration rises, the beta cells release insulin
  • If the glucose concentration falls, the alpha cells release glucagon
  • Insulin stimulates the liver and muscles to remove excess glucose from the blood and store it as glycogen
  • Glucagon stimulates the liver to convert its stored glycogen into glucose which is then released into the bloodstream
  • In this way, the concentration of glucose in the blood is kept within narrow limits GASTROINTESTINAL SYSTEM
  • Breaks down food into absorbable form.
  • Absorbs various nutrients.
  • Eliminates waste from the body. EXCRETORY SYSTEM
  • Helps eliminate the waste products from the body.
  • Maintains the blood pH, volume, pressure, osmolarity, electrolyte composition etc.
  • Produces hormones.
  • In the cells, the chemical breakdown of proteins produces the nitrogenous compound, urea. If this were allowed to accumulate in the cells it would damage or kill them.
  • The concentration of the blood and tissue fluids tends to vary. If water is lost through evaporation and sweating, the fluids become more concentrated. The intake of water dilutes the fluids
  • It is important that the concentration of blood and tissue fluid is kept within narrow limits if the cells are to function properly
  • These homeostatic functions are carried out by the kidneys Microscopic slice of kidney tissue: Blood pressure forces tissue fluid out of a clump of narrow capillaries The fluid contains urea, salts, glucose and other soluble substances The fluid trickles down this tubule and the useful substances such as glucose are reabsorbed into the blood In this tubule more or less water is reabsorbed to maintain the blood concentration Excess water, some salts and urea collect here before passing to the bladder as urine SKELETAL SYSTEM
  • Bones provide support, protection, the production of blood cells.
  • Muscles produce body movements and produce heat to maintain the body temperature. INTEGUMENTARY SYSTEM
  • Contributes to homeostasis by protecting the body and helping regulate the body temperature
  • It also allows you to sense pleasurable, painful and other stimuli in your external environment. Section through skin The sweat gland extracts sweat from the blood and passes it up the duct to the skin surface where it evaporates

Vasodilation If the body temperature rises, the blood vessels in the skin dilate (become wider) and allow more blood to flow near the surface. The heat loss from the blood through the skin helps cool the circulating blood much heat lost Vasoconstriction If the body temperature falls. The blood vessels in the skin constrict. Less warm blood flows near the surface so less heat is lost

HOW HOMEOSTATIC CONTROL MECHANISMS WORK?

  • Homeostatic control mechanisms work through ‘Feedback Mechanisms’.
  • Status of a body condition is continually monitored, evaluated, changed, re-monitored & reevaluated.

A FEEDBACK LOOP

NEGETIVE FEEDBACK

  • Mechanisms that maintain the factor at some mean value.
  • Reverse a change
  • Restore abnormal values to normal

EXAMPLE: NEGATIVE FEEDBACK

BLOOD PRESSURE REGULATION

EXAMPLE: POSITIVE FEEDBACK

MEMBRANE DEPOLARISATION

POSITIVE FEEDBACKS IN BODY

  • Action potential
  • Clotting of blood
  • Parturition
  • Release of calcium from SR
  • Sexual arousal
  • LH surge

Summary

  • Homeostasis = Maintaining body’s internal environment within in a narrow limit.
  • Homeostasis is very essential for normal functioning of body
  • Various organs and organ systems play specific roles to achieve homeostasis
  • Homeostasis is involved in continuous monitoring of body’s internal environment with respect to altering external environment
  • Components of homeostasis are ESI (Effector, Sensor, and Integrator)
  • Internal environment is maintained by –positive and negative feedback mechanisms
  • Most of the homeostasis mechanisms involve negative feedback