fetal pig dissection

Fetal Pig Dissection

Blood vessels in pigs were injected with a latex dye Arteries: Thicker, lead away from the heart

Veins: Thinner with valves, lead to the heart.

Pigs are mammals Mammary glands

Hair

Two distinct sexes

Similarities to humansPlacental

Tetrapods

Dissection Directional Terms

Anterior: towards the head end

Posterior: towards the hind end

Ventral: towards the belly

Dorsal: towards the back

External Anatomy

Compare forelimb to upper arm

Compare hindlimb to legs

Find umbilical cord

Both males and females have nipples

Look for hair

Identify as male or female

Oral Cavity and Pharynx

Oral cavity: tongue, teeth, and hard and soft palate

Pharynx: epiglottis, glottis, esophagus The jaw is opened wide enough so that the glottis and epiglottis are exposed. The epiglottis projects up through the soft palate into a region called nasopharynx. The hard palate and soft palate separate the nasal and oral cavities. When breathing, air passes through the nasal passages to the pharynx. The pharynx is the space in the posterior portion of the mouth that both food and air pass through. From the pharynx, it passes through the glottis to the trachea.

Neck region

Thymus, larynx, trachea, thyroid gland

A blunt probe is used to separate the two lobes of the thymus gland and to further separate the musculature over the trachea. The thyroid gland is darker and lies between the posterior ends of the two lobes of the thymus gland.

Thoracic Cavity

Identify heart in pleural cavity

Lungs and bronchi

Diaphragm separates from abdominal cavity

Abdominal Cavity

Identify heart, liver, lungs, small intestine, large intestine, diaphragm, urinary bladder, spleen, stomach

Food passes through the esophagus to the stomach, small intestine, and large intestine. The first part of the small intestine is the duodenum. Secretions released from the pancreas and gall bladder empty into the duodenum.

Excretory System

Identify bladder and kidney

The ureter carries urine from the kidney to the urinary bladder.

Male Pig Reproductive System

Female Pig Reproductive SystemThe urethra (carries urine from the bladder) merges with the vagina to form a common duct called the urogenital sinus.

Observe human model and compare to pig Cardiovascular

Respiratory

Digestive

Reproductive

Excretory

Respiratory System

Trachea: tube that brings air from mouth and nose

Bronchi: airways that branch going to each lung

Branch into bronchioles

Lungs: elastic breathing organs

Alveoli: thin, cup shaped membrane surrounded by capillaries

Location of gas exchange with the blood

Digestive SystemEsophagus: transports food to stomach

Stomach: muscular sac Mechanical and chemical digestion

Two sphincters control food entry and exit

Small intestine: digestionThree sections: duodenum, jejunum, and ileum

Large intestine: absorbs water, concentrates undigested materials

Liver: produces bile with digestive enzymes

Gallbladder: stores bile and releases into small intestines

Pancreas: secretes digestive enzymes

Digestive System