1. Physiology (Homeostasis)
Standard 9
Physiology (Homeostasis)

2. 9. As a result of the coordinated structures and functions of organ systems, the internal environment of the human body remains relatively stable (homeostatic) despite changes in the outside environment.

3. What is Homeostasis?
Organism’s regulation of its internal environment to maintain conditions suitable for survival.
Process of maintaining _______________ in an organisms internal environment.

4. Maintaining Homeostasis
What is homeostasis?
Homeostasis is the process by which organisms keep ______________ conditions relatively constant despite changes in external environments.
Homeostasis in the body is maintained by ____________________ __________________.

5. Maintaining Homeostasis
_____________ inhibition, or negative feedback, is the process in which a stimulus produces a response that opposes the original stimulus.
Systems controlled by feedback inhibition are fully automated and very stable.

6. Maintaining Homeostasis
An Example of Feedback Inhibition
Thermostat senses temperature change and switches off heating system
Room temperature increases
Room temperature decreases
Homeostasis is the process by which organisms keep internal conditions relatively constant despite changes in external environments. A home heating system uses a feedback mechanism to maintain a stable, comfortable environment within a house.
Thermostat senses temperature change and switches on heating system

7. Maintaining Homeostasis
Homeostasis In the Body
Maintenance of homeostasis requires the integration of all organ systems at all times.
One example is the maintenance of a stable ____________ __________________________.

8. Maintaining Homeostasis
The __________________ monitors the temperature of the skin and the temperature of organs.
If core body temperature drops, the hypothalamus:
causes blood vessels in the skin to constrict reducing heat loss from skin.
causes the skeletal muscles to contract involuntarily—to “shiver.”
This causes the body temperature to increase.

9. Maintaining Homeostasis
If the core body temperature increases, the hypothalamus:
causes blood vessels in the skin to dilate so heat can escape from the skin.
the body produces sweat, which cools the body by evaporation.
This causes the body temperature to _________________.

10. Standard 9a—b Vocabulary
Homeostasis
Cellular Respiration
Gas Exchange
Diffusion
Mitochondria
Oxygen
Glucose
Digestive System
Pituitary Gland
Hypothalamus
Circulatory System
Alveoli
ATP
Reflex Arc
Hormones
Respiratory System
Central Nervous System
Gonads
Insulin
Thyroid

11. 9a. Know how the complementary activity of major body systems provides cells with oxygen and nutrients and removes toxic waste products such as carbon dioxide.

12. Organization of the Body
How is the human body organized?
The levels of organization in a multicellular organism include:
_________
__________
____________
_______________________
Every cell in the human body is both an independent unit and an interdependent part of a larger community—the entire organism.

13. Organization of the Body
Cells
A cell is the basic unit of structure and function in living things.
Individual cells in multicellular organisms are specialized.
___________________ _________ are suited to perform a particular function.

14. Organization of the Body
________________ System
Structures: Heart, blood vessels, blood
Function: Brings oxygen, nutrients, and hormones to cells; fights infection; removes cell wastes; helps to regulate body temperature

15. Organization of the Body
________________ System
Structures: Nose, pharynx, larynx, trachea, bronchi, bronchioles, lungs
Function: Provides oxygen needed for cellular respiration and removes excess carbon dioxide from the body

16. Organization of the Body
__________________ System
Structures: Mouth, pharynx, esophagus, stomach, small and large intestines, rectum
Function: Converts food into simpler molecules that can be used by the cells of the body; absorbs food; eliminates wastes

17. 37–1 The Circulatory System
The circulatory system and respiratory system work together to supply cells with the _________________ & _____________ they need to stay alive.

18. The Heart Circulation Through the Heart
The ________________ divides the right side of the heart from the left.
It prevents the mixing of oxygen-poor and oxygen-rich blood.
Circulation Through the Heart
Blood enters the heart through the right and left atria.
As the heart contracts, blood flows into the ventricles and then out from the ventricles to either the body or the _________________.

19. The Heart ______________________ Circulation
One pathway circulates blood between the heart and the lungs.
This pathway is known as _______________________ circulation.
In the lungs, carbon dioxide leaves the blood and oxygen is absorbed. The oxygen-rich blood returns to the heart.
_________________________ Circulation
The second pathway circulates blood between the heart and the rest of the body.
This pathway is called _____________________ circulation.
After returning from the lungs, the oxygen-rich blood is pumped to the rest of the body.

20. The Heart Circulation of Blood through the Body
Capillaries of head and arms
The Heart
Circulation of Blood through the Body
Superior vena cava
Pulmonary artery
Aorta
Pulmonary vein
Capillaries of right lungs
Capillaries of left lung
The circulatory system is divided into two pathways. Pulmonary circulation carries blood between the heart and the lungs. Systemic circulation carries blood between the heart and the rest of the body. 
Inferior vena cava
Capillaries of abdominal organs and legs

21. Ch 37—3 What Is Respiration?
In biology, respiration means two different things.
_____________________ respiration is the release of energy from the breakdown of food in the presence of oxygen.
At the organism level, respiration is the process of ____________ ________________—the release of carbon dioxide and the uptake of oxygen between the lungs and the environment.

22. The Human Respiratory System
What is the function of the respiratory system?
The basic function of the human respiratory system is the exchange of ___________ & ___________ ______________ between the blood, the air, and tissues.

23. Pharynx Nose Larynx Trachea Mouth Lungs Epiglottis Bronchus
Bronchioles
The respiratory system is responsible for the exchange of oxygen and carbon dioxide. Air moves through the nose, pharynx, larynx, trachea, and lungs. After reaching the lungs, the trachea branches into smaller and smaller tubes called bronchioles, which end in alveoli, or air sacs.
Diaphragm

24. The Human Respiratory System
Alveoli
Bronchioles subdivide into millions of tiny air sacs called alveoli.
Bronchiole
The respiratory system is responsible for the exchange of oxygen and carbon dioxide. After reaching the lungs, the trachea branches into smaller and smaller tubes called bronchioles, which end in alveoli, or air sacs.

25. The Human Respiratory System
Alveoli are grouped in clusters.
A network of capillaries surrounds each alveolus.
Pulmonary artery
Pulmonary vein
The respiratory system is responsible for the exchange of oxygen and carbon dioxide.
Capillaries

26. Gas Exchange O2 Gas exchange takes place in the ___________.
Oxygen _______________ into the blood. O2
Gas exchange occurs by diffusion across the membrane of an alveolus and a capillary.
Capillary

27. Gas Exchange O2
Carbon dioxide in the blood ______________ into the alveolus.
CO2
Gas exchange occurs by diffusion across the membrane of an alveolus and a capillary. 
Capillary

28. 38–2 The Process of Digestion
Mouth
Pharynx
Salivary glands
Esophagus
Liver
Stomach
The digestive system includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. Because the pancreas and most of the gallbladder are behind other organs, their locations are indicated by dotted lines.
Pancreas
Gallbladder
Large intestine
Small intestine
Rectum

29. Digestive System What is the function of the digestive system?
The function of the digestive system is to help convert foods into simpler molecules that can be absorbed and used by the cells of the body.

30. The Stomach The Stomach
Food from the _____________________ empties into the stomach.
The stomach continues mechanical and chemical digestion.
Alternating contractions of three smooth muscle layers churn food.

31. The Stomach Chemical Digestion
The stomach lining has millions of gastric glands that release substances into the stomach.
Some glands produce mucus, which lubricates and protects the stomach wall.
Other glands produce ___________________________ _____________________, which makes the stomach contents very acidic.
Other glands produce pepsin, an enzyme that digests protein.

32. The Stomach
______________ and hydrochloric acid begin protein digestion.
Pepsin breaks proteins into smaller polypeptide fragments.
Other enzymes are denatured by stomach acid.

33. The Stomach Mechanical Digestion
The stomach contracts to churn fluids and food, gradually producing a mixture known as ____________.
After 1–2 hours, the pyloric valve between the stomach and small intestine opens and chyme flows into the small intestine.

34. The Small Intestine The Small Intestine
As chyme is pushed through the pyloric valve, it enters the duodenum.
The duodenum is the first of three parts of the small intestine, and is where most digestive ______________ enter the intestine.

35. The Small Intestine
Most chemical digestion and ______________ of food occurs in the small intestine.
Accessory Structures of Digestion

36. The Small Intestine During digestion, the pancreas:
Accessory Structures of Digestion
Just behind the stomach is the _________________.
During digestion, the pancreas:
produces enzymes that break down ___________________, _____________, ___________, and _____________ ___________ .
produces sodium bicarbonate, a base that neutralizes stomach acid so that these enzymes can be effective.

37. The Small Intestine
Assisting the pancreas is the _____________, which produces bile.
Bile dissolves and disperses droplets of fat in fatty foods. This enables enzymes to break down smaller fat molecules.
Bile is stored in the __________________.

38. Absorption in the Small Intestine
The small intestine is adapted for the absorption of nutrients.
The folded surfaces of the small intestine are covered with fingerlike projections called ____________.

39. Absorption in the Small Intestine
Cell surfaces of villi have more projections called ________________.
These provide an enormous surface area for the absorption of nutrient molecules.
Slow, wavelike contractions of smooth muscles move the chyme along this surface.

40. Absorption in the Small Intestine
Nutrient molecules are _____________ into the cells lining the small intestine.
Most products of carbohydrate and protein digestion are absorbed into the capillaries in the villi.
Molecules of undigested fat are absorbed by ______________ ____________.

41. Summary
Each body system is only one small part of the total organism. The systems work ________________ for optimal functioning of the body as a whole. The respiratory system brings ____________ into the body and removes ___________ __________. The digestive system breaks down food and transfers _____________ to the bloodstream. The circulatory system transports _____________ & ______________ to cells and carries away wastes.