Dissection Guide to the Rat

The Norway rat (Rattus norvegicus)

Rat Dissection

Scientific Name: Rattus norvegicus

Common Name: Rat

Kingdom- Animalia Phylum- Chordata Subphylum- Vertebrata Class- Mammalia Order- Rodentia Family: Muridae

RATS

Anatomical Terms

Cranial-toward the head Caudal-toward the tail Dorsal-toward the backbone Ventral-toward the belly side Lateral-toward the side Medial-toward the middle Proximal: closer to the the base of a structure Distal: farther away from a structure

External Anatomy

• The body is long and cylindrical:

• Head, neck, trunk, anterior limbs, posterior limbs, tail.

External Anatomy

• Head: eyes, nostrils, external ears (auriculars), mouth, whiskers.

• Neck: (head , trunk).• Trunk: (thorax, abdomen).• Ant. limbs: 4 digits• Post. limbs: 5 digits

Male External Features:

Female External Features:

Diastema

Mouth Cavity

Cleft lib

Rhinarium

Mouth Cavity

Rat Dissecting Rat Dissecting Process:Process:

Rat Dissection REMOVING SKIN

XX

Rat Dissection REMOVING SKIN

Rat Dissection REMOVING SKIN

Internal Anatomy

Rat Dissection

Digestive System

Lesson One

Rat Dissection ORAL CAVITY

Rat Dissection ORAL CAVITY

Rat Dissection ABDOMINAL

CAVITY

Rat DissectionDIGESTIVE ORGANS

Rat DissectionDIGESTIVE ORGANS

Rat DissectionDIGESTIVE ORGANS

Rat DissectionDIGESTIVE ORGANS

Rat DissectionDIGESTIVE ORGANS

Appendix

Colon

Ileum

CecumDuodenum

Stomach

Esophagus

Rat Dissection

Urinogenital System

Lesson Two

Rat DissectionEXCRETORY

ORGANS

Rat DissectionUROGENITAL

ORGANS

Rat Dissection

1. Stomach2. Kidney3. Ovary4. Oviduct5. Uterine Horn6. Rectum7. Urinary Bladder

FEMALE REPRODUCTIVE ORGANS

Rat Dissection

1. Coagulating Gland2. Urinary Bladder3. Vas Deferens4. Epididymis5. Small Intestines6. Seminal Vesicle7. Prostate Gland8. Penis9. Testis10.Scrotum

MALE REPRODUCTIVE ORGANS

Key words and Functions:Key words and Functions:

Seminal vesicleSeminal vesicle: secrete thick liquid to transport sperms.

Coagulating glandCoagulating gland: is to secrete fluids to form the copulatory plug to help ensure fertilization.

Prostate glandProstate gland: secrets thin alkaline solution. Vas deferensVas deferens: transportation, ejaculation. EpididymisEpididymis: transportation, maturation, ejac.

Cowper’s gland: Cowper’s gland: secretions may lubricate, flush out urine or form gelatinous plug.

The preputial glandsThe preputial glands: produce pheromones. The preputial glands of female animals are

sometimes called clitoral glands.clitoral glands. TestisTestis: sperm production. PenisPenis: Copulation. ScrotumScrotum: protection.

Rat Dissection

Circulatory System

Lesson Three

Rat Dissection HEART

1. Blue is deoxygenated blood (from the body, going to the lungs)

2. Red is oxygenated blood (from the lungs, going to the body)

3. Arteries are thick walled

4. Veins are thin walled

To LUNGS

To LUNGS

From LUNGSFrom LUNGS

From BODY

From BODY

To BODY

Rat Dissection

1. Trachea2. Heart3. Lung4. Diaphragm

THORACIC CAVITY

Rat DissectionRESPIRATORY

ORGANS

Carotid

Jugular

Esophagus

Rat Dissection HEART + LUNGS

Arterial System

Rat DissectionRat Thoracic

Arteries

Venous System

Venous System

Rat Dissection THORACIC

CAVITY

 

  

Rat DissectionRat Abdominal

Cavity

Rat Dissection

1. Abdominal Aorta2. Renal Artery (left)3. Renal Vein (left)4. Inferior Vena Cava5. Hepatic Portal

Vein

ABDOMINAL CIRCULATION

Rat Dissection

Endocrine System

Lesson Four

Rat Dissection

Nervous System

Lesson Five

Organizational Levels of the Nervous System

Central Nervous System (CNS): Brain and Spinal Cord Control and Integration Center

Peripheral Nervous System (PNS): Nerves from brain and spinal cord Communication lines between CNS and rest of body

Sensory (afferent) Division Body Receptors Sends stimulus from receptors to CNS

Motor (efferent) Division Motor Neurons Sends stimulus from CNS to muscles (and glands)

Autonomic Nervous System Involuntary Control Conducts impulses from the CNS to involuntary muscles

Somatic Nervous System Voluntary Control Sends stimulus from CNS to skeletal muscles

Sympathetic Division Fight or Flight Mobilizes involuntary systems during emergencies

Parasympathetic Division Resting and Digesting Promotes non-emergency involuntary functioning

medulla oblongata

Nervous System

Rat Dissection

Skeletal System

Lesson Six