Chapter 6: Physiology

Question 1

Describe similarities of birds to mammals

Answer 1

• both are endotherms
• Birds and mammals regulate their body temperatures to be just below temperatures that destroy body proteins

Question 2

Describe differences in birds vs. mammals

Answer 2

birds have:
Higher metabolic rate
Higher body temperature
Higher cardiac output
More efficient respiratory system
Higher blood pressure
Higher blood sugar concentration

Question 3

External nares

Answer 3

• can have operculum and ceres

Question 4

Operculum

Answer 4

convers and protects nostrils

Question 5

Cere

Answer 5

• soft, fleshy, typically bare patch at the base of the upper side of the bill
• may play role in respiration or smell

Question 6

Turbinates

Answer 6

• conchae
• Surfaces of the conchae cleanse and heat the air before it enters the respiratory tract
• nasal passages bring air into oral cavity

Question 7

Glottis

Answer 7

• opening to the trachea and larynx
• in the floor of the pharynx, surrounded by pharynx

Question 8

Trachea

Answer 8

The typical bird trachea is 2.7 times longer and 1.29 times wider than that of similarly-sized mammals
- larynx(cartilaginous rings) is a valve that allows air into the trachea

Question 9

Syrinx

Answer 9

• located at the lower end of the trachea, and above the bronchial entrances
• voice-box of birds, where trachea divides into lungs

Question 10

Describe the 3 types of syrinx

Answer 10

• tracheal syrinx: one trachea passage, surrounded by lots of muscle, one narrow opening into bronchus
• bronchial syrinx: wide trachea, small amounts of muscle, splits into 2 passageways to 2 separate bronchus
• tracheobronchial syrinx: mediator of muscle, wide trachea, has pessulus at the top of the divide into two bronchus passages

Question 11

Describe relationship between the lungs and the air sacs (also can be known as unidirectional ventilation)

Answer 11

• expiration: airs sacs can hold air before oxygen exchange (posterior air sacs) in the lungs or inspiration: after the air has left the lungs (anterior air sacs)
  -expiration: anterior air sacs lead out into environment
• air can travel over cervical air sacs in order to create bird calls and sounds

Question 12

What are parabronchi?

Answer 12

-tightly packed, thick‐walled tubes
- Walls contain hundreds of air vesicles within the tissue, sometimes called air capillaries, which intertwine with a network of blood capillaries

Question 13

Cross current ventilation

Answer 13

• air flow going through air vessel one direction, blood flow going through blood capillary in the other direction
• across air flow, oxygen is high and slowly decreases; CO2 is low and slowly increases
• across blood flow, CO2 is high and slowly decreases; oxygen is low and slowly increases

Question 14

Which muscles are used for ventilation?

Answer 14

the intercostal muscles, encompass around the sternum and ribcage

Question 15

How do gases cross the eggshell in birds and diffuse into the embryo?

Answer 15

• pores in the eggshell allow air to pass the allantois and chorion membranes for the egg to get air
• pores carry oxygen to the chorioallantois(respiratory membrane) over the outer and inner shell membrane

Question 16

Name chambers of bird heart

Answer 16

• right atrium, left atrium, right ventricle, and left ventricle

Question 17

Right Atrium

Answer 17

receives deoxygenated blood (rich in carbon dioxide) from the head and body via the caval veins

Question 18

Right ventricle

Answer 18

pumps that blood from right atrium into the pulmonary arteries to be oxygenated in the lungs

Question 19

Left atrium

Answer 19

receives oxygenated blood from the lungs via the pulmonary veins

Question 20

Left ventricle

Answer 20

contracts to pump that blood into the aorta for distribution throughout the body
- wall thicker than right ventricle, since pumping blood requires lots more power

Question 21

Bird vs. human hearts

Answer 21

• Birds tend to have larger hearts than mammals (relative to body size and mass)
• Avian hearts also tend to pump more blood per unit time than mammalian hearts

Question 22

Name the main bird arteries

Answer 22

• large renal artery from top to bottom, branches into limbs and bottom
• one pectoral artery
• has left and right subclavican artery
• pulmonary arteries in lungs
• brachial arteries in wings

Question 23

name 2 main venous systems in birds

Answer 23

• Hepatic portal system
• Renal Portal System

Question 24

Hepatic Portal system

Answer 24

• blood from GI tract that goes back to liver (filters out toxins)
• hepatic veins from liver, Portal veins back to liver

Question 25

Renal Portal System

Answer 25

• blood flow through kidneys before it goes back to the heart

Question 26

Name blood cells in birds

Answer 26

• Red blood cells (nucleated)

Types of White blood cells:
* Lymphocytes
* heterophils
* Monocytes
* Eosinophils

Question 27

Red blood cells

Answer 27

• carry oxygenated blood

Question 28

White blood cells

Answer 28

• help fight bodily infections, leukocytes

Question 29

Lymphocytes

Answer 29

• some associated with digestion
• produce antibodies
• involved in immune response

Question 30

Heterophils

Answer 30

• phagocytic leukocytes
• great ability to kill off bacteria/antigens

Question 31

monocytes

Answer 31

help fight off infection

Question 32

eosinophils

Answer 32

• fight off parasites, fungi, allergens