Avian Anatomy Gross Anatomy 2

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Questions and Answers

What is the primary function of the proventriculus in the avian gastrointestinal system?

To store food temporarily

To secrete digestive enzymes (correct)

To grind food into smaller particles

To absorb nutrients

Which of the following statements is TRUE regarding the salivary glands of birds?

Birds that consume wet diets have more developed salivary glands.

They are highly developed in all bird species.

Salivary glands vary in development based on diet type. (correct)

Most birds lack salivary glands entirely.

What distinguishes the crop in certain bird species?

It is absent in all avian species.

It serves as a diverticulum of the esophagus for temporary food storage. (correct)

It functions solely for nutrient absorption.

It is a muscular structure that aids in grinding food.

How does the avian respiratory system differ from the mammalian system?

Birds have a more complex air sac system for continuous airflow. Signup and view all the answers

Which structure in the avian gastrointestinal system is a remnant of the embryonic yolk sac?

Vitelline diverticulum Signup and view all the answers

What is a primary distinction between the avian and mammalian respiratory systems?

Pneumatic bones communicating with air sacs Signup and view all the answers

Which structure in birds functions similarly to the mammalian larynx?

Syrinx Signup and view all the answers

What is the function of air sacs in avian anatomy?

To allow unidirectional airflow through the respiratory system Signup and view all the answers

Which of the following statements about avian lungs is correct?

Their size remains constant during ventilation. Signup and view all the answers

In comparing the circulatory systems, how does the avian heart differ from that of mammals?

The apex of the avian heart is covered by the liver. Signup and view all the answers

Which vein is larger in birds, contributing to ease of venipuncture?

Right jugular vein Signup and view all the answers

What is a key feature of the avian respiratory system that enhances efficiency?

Continuous airflow through the lungs Signup and view all the answers

Which of the following correctly describes the anatomical relationship of the avian heart?

It is positioned cranially to the lungs. Signup and view all the answers

What is the function of the coracoid bone in birds?

It connects the clavicle to the sternum. Signup and view all the answers

Which bones fuse with the synsacrum in birds?

Ilium, ischium, and pubis Signup and view all the answers

How do pneumatic bones contribute to bird anatomy?

They decrease overall body weight. Signup and view all the answers

What is a notable feature of the bird's femur in comparison to mammalian bones?

It resembles the mammalian bone structurally. Signup and view all the answers

Which bone arrangement takes place in the distal part of the bird's pelvic limb?

The distal row of tarsal bones fuse with the metatarsal bone. Signup and view all the answers

What characteristic of bird bones can lead to common fractures?

Their brittle nature. Signup and view all the answers

What role does the tibia serve in birds' pelvic limb?

It combines with the tarsal bones to form the tibiotarsus. Signup and view all the answers

Which structure in birds assists with locomotion and can vary for different functions?

Tarsometatarsus Signup and view all the answers

What does the furcula represent in bird anatomy?

It is a fusion of the right and left clavicle. Signup and view all the answers

Which bone is primarily used as a brace for the wing movement in birds?

Coracoid Signup and view all the answers

What is the primary function of the supracoracoideus muscle in the context of a bird's flight?

To assist in take-off, not sustained flight Signup and view all the answers

How do the air sacs in birds differ from mammalian respiratory structures?

Birds have multiple air sacs that enable unidirectional airflow Signup and view all the answers

Which statement accurately describes the syrinx in songbirds?

It allows songbirds to create multiple pitches simultaneously Signup and view all the answers

How do the lungs of birds maintain a constant volume compared to mammalian lungs?

Birds' lungs remain in close contact with the ribs Signup and view all the answers

What is a key structural feature of the trachea in birds?

It is made up of complete cartilaginous rings Signup and view all the answers

What role does the laryngeal mound play in avian anatomy?

It serves as a landmark for endotracheal intubation Signup and view all the answers

Which of the following statements regarding the functions of the pectoralis and supracoracoideus muscles is correct?

These muscles insert on the same bone, but have opposing actions Signup and view all the answers

What distinguishes the function of the syrinx from that of the larynx in mammals?

The syrinx is located at the bifurcation of the trachea and permits unique sounds Signup and view all the answers

Which specific type of air sac is unique to chickens?

Single clavicular air sac Signup and view all the answers

What characterizes the respiratory system in terms of its anatomy in birds?

Birds possess a unique arrangement of air sacs facilitating airflow Signup and view all the answers

Study Notes

Avian Anatomy

Gross Anatomy 2 was lectured by Dr. Cristian Martonos.
Previous lecturer was Dr. Melissa Kehl.
Images of various bird species are shown.

Learning Objectives

Understand anatomical adaptations specific to birds in integument, cardiorespiratory, gastrointestinal, musculoskeletal, urogenital and immune systems.
Understand and apply clinical applications of avian anatomy.
Recognize diseases and conditions unique to birds and their anatomical adaptations.
Understand the anatomical position of the avian skeleton.
Identify external structures during a physical examination.
Differentiate between types of feathers.
Identify soft-tissue organs (respiratory, gastrointestinal, immune, and urogenital tracts).

Integument: Skin

Very thin skin.
Poor blood vessel and nerve supply.
No sweat glands.
Feather tracks are present.
Easily bruises.
Scales on feet and legs are cornified epidermis.
Beaks are derived from skin.
Uropygial gland is present.

Integument: Uropygial gland/preen gland

Located at the base of the tail.
Dorsal to the caudal vertebrae.
Important for waterproofing and insulating submerged body parts in waterfowl.
Absent in most ratites and some amazon parrots.

Integument: Ornamental Features

Comb
Wattle
Snood or frontal process
Ear lobes

Integument: Skin - Patagium

Triangular area between shoulder, elbow, and wrist joints.
Increases surface area of wings.
Composed of skin and elastic tissue, including patagial ligament.
Important for flight aerodynamics.

Integument: Feathers

Pteryla: tracts in skin where feathers grow.
Apteria: featherless skin between pterylae.
Contour feathers: externally visible feathers, covering the down feathers and defining the body shape and wings.
Down feathers: lack barbules, under contour feathers, conserving heat and being abundant in waterfowl.

Skeletal System

Skull: lower jaw articulates with upper jaw via quadrate bone; upper jaw is movable relative to the cranium; large orbits separated by interorbital septum; single occipital condyle.
Pneumatic bones (hollow) include humerus and femur.
Bones are strong but brittle and open fractures common.
Thin cortex
Trabeculae for strength
Notarium: fusion of dorsal spinous processes of most thoracic vertebrae.
Keel and Sternum: support internal organs, respiration, body conditioning; good for radiography positioning.
Synsacrum: fusion of last two or three thoracic, all lumbar, all sacral and first few caudal vertebrae.
Pygostyle: fusion of most caudal vertebrae (3-4 in most birds).
Wing feathers (remiges): responsible for flight and include primary and secondary flight feathers.
Tail feathers (rectrices): known as tail feathers.
Clavicles (wishbone): fused and form the furcula.
Coracoids: form a brace supporting the wing strokes.
Forelimb/wing: modified for flight.
Three metacarpals instead of digits for a wing.
Pelvic limb: important for locomotion on the ground.
Hip bones (ilium, ischium, and pubis): fused dorsally with the synsacrum.
Tarsal bones fused with metatarsal bone = tibiotarsus.

Muscular System

Pectoralis: more superficial, powerful downstroke of the wing.
Supracorocoideus: smaller, used for take-off.
Pectorals and supracoracoideus originate on the keel of the sternum, insert on the humerus. Having opposing functions.

Respiratory System

Lungs: in contact with vertebral ribs, constant volume.
Air sacs: external to lungs, 8 in Chickens: cervical, clavicular (interclavicular), and paired cranial thoracic and caudal thoracic; abdominal air sacs.
Syrinx: vocal apparatus at tracheal bifurcation.
Air sacs allow for unidirectional airflow through the lungs

Circulatory System

Heart structure is similar to mammals but isn't covered by lungs.
Heart apex is covered by the liver.

Venipuncture Sites

Jugular vein (right larger than left).
Medial plantar metatarsal vein (medial side of the tibiotarsus).
Cutaneous ulnar vein (branch of brachial)..

Gastrointestinal System

Lack a soft palate.
Hard palate contains the choana.
Choana connects the oral and nasal cavities.
Choana lined with caudally directed papillae.
Salivary glands and taste buds are poorly developed.
More developed in birds that eat dry diets (seeds).
Esophagus (down the right side of the neck).
Crop: diverticulum of the esophagus.
Some birds, like chickens and turkeys, have a crop to store food.
Proventriculus (glandular stomach): secretes digestive enzymes.
Ventriculus (muscular stomach): breaks up larger food.
Duodenum, jejunum, ileum; intestinal tract.
Cysticoenteric duct: from gall bladder.
Hepatoenteric duct: from left lobe of liver.
Vitelline diverticulum (Meckel's) : remnant of the embryonic yolk sac.
Paired ceca: (10)
Descending colon: (11)

Urogenital System

Paired kidneys with elongated 3 lobes (cranial, intermediate, caudal).
Urinary bladder is absent (urates instead of urea).
Males have paired testes inside the abdomen (no scrotum).

Egg Production

Infundibulum: 7 cm long, thin coating of dense albumen, collects egg from ovary.
Magnum: 30 cm long, albumen production.
Isthmus: 8 cm long, primarily shell membranes.
Shell gland: 8 cm long, shell formation.
Vagina: (7): passage of egg seconds.

Immune System

Palpable lymph nodes absent (in mammals).
Thymus and bursa of Fabricius regress early in life.
Spleen at the junction of proventriculus/ventriculus; enlarged with diseases (e.g., chlamydiosis).

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Description

Test your knowledge on avian anatomy as covered in Gross Anatomy 2 with Dr. Cristian Martonos. This quiz explores various anatomical adaptations specific to birds, including their integument, cardiorespiratory, and gastrointestinal systems. You will also learn to recognize diseases unique to birds and apply clinical knowledge effectively.