Rat Dissection

• We will break up this dissection into 6 parts; External Features, Respiratory system, Digestive System, Circulatory System, Excretory System, and Reproductive system.

• You are responsible to know the functions and location of the organs and features gone over in this lab.

• This lab will be split up into 5 days

– Day 1, External features and Respiratory system

– Day 2, Digestive System

– Day 3, Circulatory System

– Day 4, Excretory and Reproductive System

– Day 5, Reproductive System and make up

• You will have a particle exam on the Monday after the dissection

Incision

• Use your razor blade to cut along dotted line, CAREFULL!

• Don’t cut to deep but deep enough to get through muscles

• You are going to have to break the ribs to get into the upper Thoracic cavity

• Good Luck

External Features/ Respiratory

• Ear

• Whisker

• Nostril

• Mouth

• Anus

• tail

• claws

• Eyes

• Mouth

• Larynx

• Trachea

• Bronchus

• Lung

• Diaphragm

Functions of external an respiratory systems

• External Features:

– Diaphragm- This is a muscular sheet that separates cavities and its action is to draws air into the lungs.

– Ear, Whisker, Nostril, Eyes – Sensory organs

– Tail – Balance

– Claws – defense, eating, grasping, climbing

• Respiratory System:

– Mouth and Nostril – Intake for air

– Larynx – produce sound for communication

– Trachea – Tube to bring air into lungs

– Bronchus – Branches into lungs

– Lung – Exchange oxygen form air into blood an expel carbon dioxide waste

– Diaphragm - Muscle that helps fill lung with air

Digestive System

• Mouth

• Epiglottis

• Esophagus

• Gall Bladder (rat doesn’t have one)

• Pancreas

• Stomach

• Small intestine

• Mesentery

• Large intestine

• Caecum

• Rectum

• Spleen

Functions of Digestive system

• Mouth – Break down food both mechanically and physically

• Epiglottis –Barrier to prevent food from entering the lungs

• Esophagus- Muscular tube to carry food to stomach

• Pancreas- This organ gives digestive enzymes to the small intestine.

• Stomach- This is a curved, bag-like structure under the left side of the liver. Helps break down food both chemically and physically

• Small Intestine- This is a long, coiled tube that leaves the stomach. Absorption and digestion of food takes place here.

• Mesenteries- These are translucent membranes attached to and holding the internal organs in place. Blood vessels travel along them and fat bodies are often present.

• Large intestine – Long tube that collects waste

• Rectum – Last stop, This is the muscular organ, which removes water from waste and helps expel the waste from the body.

• Cecum - contains bacteria that help the rat to break down cellulose

• Spleen- This organ stores red blood cells and manufactures white blood cells.

Spleen

Circulatory System

• Heart

• Pericardium

• Vena Cava

• Aorta

• Left and Right Atrium

• Left and Right Ventricle

• Vein

• Artery

Functions of Circulatory System

• Heart – pump that supplies the body with blood

• Pericardium- protects the heart

• Vena Cava- supplies used blood to Right atrium

• Aorta – Main artery out of left ventricle

• Left Atrium and Ventricle – chambers that pump blood to body

• Right Atrium and Ventricle – chambers that pump blood to the lungs

• Vein – (back to heart), pathway for used blood

• Artery – (away from heart), pathway for oxygen rich blood(except pulmonary arteries)

Heart

Excretory System

• Kidneys

• Liver

• Ureter

• Urethra

• Urinary Bladder

Functions of Excretory System

• Liver- This is a large, brown organ takes up most of the anterior of the cavity. It consists of four lobes, and is used for removing toxins from the blood.

• Kidney- This organ filters wastes from the blood.

• Ureter- This is a tube that carries the wastes away from the kidney.

• Urinary Bladder- This organ is a sack which temporarily stores urine.

• Urethra- This organ is the tube that passes out of the bladder to the outside of the body.

Female Reproductive System

• Uterus

• Ovary

• Vagina

Functions

• Ovary- An egg producing gonad of the female.

• Uterine horn (uterus)- female reproductive structure where eggs are stored or fertilixed or where development of the youn occurs.

• Vagina- muscle tube for receiving sperm.

Female repro

Male Reproductive System

• Testes

• Scrotum

• Vas Deferens

• Penis

Functions of Male Reproductive System

• Testes – gamete producing organ

• Scrotum – Contain Testes

• Vas Deferense – tube that carries sperm

• Penis – organ that deposits sperm in the female reproductive system

Male repro

• http://www.utm.edu/~rirwin/RatAnat.htm

• Rat Quiz

• http://www.utm.edu/~rirwin/RatAnat.htm

• Test Questions

• http://faculty.fmcc.suny.edu/mcdarby/Pages/Lab%20Exercises/Rat.htm