BY 124L: Fetal Pig Dissection Part 1

Fetal Pig is meant to be a ________ comparison with anatomy. Different aspects will be __________ to humans.

direct, different

What are Homologous Structures? Some examples?

similar structures in different species; our palm structure, bat wings, seal flipper

What are the four planes of the pig we are required to know?

cranial to caudal (head to tail), dorsal to ventral (back to stomach)

What order are pigs in?

Artiodactyla

What are the three main body divisions of the pig?

head, trunk, tail

What does the head of the pig contain? (4 things)

Eyes (not open), Ears (pinnae), external nares (nostrils), and vibrissae (whiskers)

What are vibrissae?

used for tactile sensation

What are the two parts of the trunk?

thorax and abdomen

What separates the thorax from the abdomen?

diaphragm

What does the thorax hold?

heart and lungs

What does the abdomen hold?

digestive, excretory, and reproductive tacts

Forefeet and Hind feet are equipped with what?

split hooves

What are split hooves made up of?

keratinized epidermal layers (protection for toes, or digits)

The foot of a pig is compressed or elongated?

elongated

Wrist and ankle are carried ___ the ground. What are these not?

off, not the elbow and knee

What is digitigrade?

Orientation of forelimbs and hind limbs indicating a form of locomotion where the heel and each foot is elevated during each step

What are two examples of plantigrades?

humans and primates

What is plantigrade?

Heel and digits make contact with the ground with each step

Where is the umbilical cord located?

ventral side of abdomen

What are the two things the umbilical cord does?

Caries Nutrient and Oxygen Rich Blood to the fetus; Removes metabolic waste products and CO2 from the fetal system

Males and Females both have an ______?

anus

What is excretion? urine

Elimination of metabolic waste products (Urine)

What is egestion?

Elimination of digestive contents that can NOT break down (Fecal)

What structure is on the abdominal region that serves a purpose in females and no purpose in males?

Mammary Papillae

What is the purpose of mammary papillae in female pigs?

contain the mammary glands

Where is the urogenital opening located? in female pigs

Ventral to anus, near tail base

What is the urogenital opening? in female pigs

Opening for reproductive pathway and release of urine from the body

In female pigs what structure might obscure seeing the urogenital opening?

Genital papilla

What is genital papilla?

Short projection that develops into the clitoris

The genital papilla is a _______ homologue to the male penis, sends stimulation to the brain

direct

Where is the Urogenital Opening located on male pigs?

Ventral side, caudal to the umbilical cord

The Urogenital Opening in male pigs is the opening to what that releases what two things?

urethra, sperm and urine

In a male pig, the _____ is embedded in the tissues of the abdomen

penis

Where is the scrotum located in a male pig?

near the anus

________ form deep from the cavity (near kidneys) and migrate caudally into the scrotum (they drop)

Testes

Sperm production sensitive to temperature, what degree difference to testes stay at compared to the rest of the body?

2°C

The digestive system responsible for?

food break down

The digestive system breaks down ____________ and ____________ for the body to absorb smaller, more usable compounds. What type of digestion is this?

mechanically and chemically, enzymatic

_____________ balance so that we do not constantly have to eat

Endothermic

3 pairs of salivary glands are located along the __________ surfaces of the head beneath connective tissue and skin

lateral

What are the three types of salivary glands?

parotid, mandibular, sublingual

What is the parotid gland?

largest, ventral to the ear;

parotid duct carries digestive enzymes rostral from the gland to the oral cavity to mix with food

What is the Mandibular gland?

oval shape

What is the sublingual gland?

Ventral surface of the jaw, near tongue

All 3 pairs of glands ___________ secretions that combine in the mouth to produce Saliva

produce

What does saliva do?

Lubricates the food and starts digestive chemical reactions

What is Amylase?

Major enzyme in starch breakdown

_________ capture and hold food, enhancing food absorption and possible injury

Teeth

What does the hard palate separate?

the oral and nasal cavity

What is the soft palate? What does it allow for us to do?

extension of the hard palate; Allows for us to breathe and eat SIMULTANEOUSLY

What is the nasopharynx?

is caudal to the soft palate, Leads to external nares

What is the esophagus?

narrow tube that pushes food into the stomach

What is the glottis?

Opening to larynx

What is the epiglottis?

a thin cartilage layer, protects the glottis

What is the tongue?

muscular organ

What are the papillae on the tongue?

Bumps near the tip and base

The mouth begins the __________ process. What does the mouth do to food?

digestion; is broken down, softened, and enters esophagus

What is the shape of a stomach?

J-shaped

Where is the stomach located on a pig?

left side, under the liver

What is rugae?

Small folds of smooth muscle lined with epithelium that help churn food and mix the chemicals

The stomach will empty in the what?

duodenum

What is the duodenum?

First portion of the small intestine

Several accessory organs empty digestive fluids here

What is the largest organ in the abdominal cavity?

liver

What does the liver produce? What does bile contain? Is it enzymatic?

bile, no digestive enzymes but has bile salts, not enzymatic

Where is bile stored? Where is this organ located?

gallbladder, underside of the liver

Bile is released into the ______ Duct, then the _________ Bile Duct, and finally the _________

Cystic, Common, Duodenum

What supports the stomach?

the Pancreas

What does the pancreas produce?

several digestive enzymes and hormones

What are the three parts of the small intestine?

duodenum, jejunum, ileum

The Duodenum receives the food digestion and enzyme mix, what is this now called?

chyme

Food leaves the Duodenum and enters the __________, second portion of small intestine

Jejunum

What is mesentery? What portion of the small intestine is it used in?

connective membrane that suspends and binds, Used within the Jejunum

Mixture (chyme) goes through the ________ into the colon

cecum

What major thing occurs in the colon?

water reabsorption

What are the three regions of the colon?

ascending, transverse, descending

What does the descending colon lead to?

the rectum

What is the rectum?

Final site of water reabsorption and feces dehydration; Feces is the food particles not digested; THEY ARE EGESTED, and eventually defecated

What type of heart do mammals have?

4 chambered

What are the 2 major circulatory paths that deliver blood?

pulmonary and systemic circuit

What is the flow of blood for the pulmonary circuit?

heart, lungs, heart

What is the flow of blood for the systemic circuit?

heart, body, heart

What are the 4 chambers of the heart?

right and left ventricle (on bottom) and right and left auricle (on top)

Ventricles are ______ walled, and pump blood OUT of the heart

thick

Auricles receive blood, and pass it to the __________

ventricles

The respiration system brings fresh oxygen to the bloodstream and carrying off _________ ________

carbon dioxide

(respiration) Simple _________ by spongy, moist membranes within the lungs

diffusion (simple squamous cells are leaky)

Air is inhaled and warmed where?

in the lungs

The lungs filter out what two things?

particles and germs

Nose hairs help to capture what?

particles

Air enters the nasopharynx with the _________ permitting it to enter to glottis. (leads to the larynx and trachea)

epiglottis

What is the trachea?

Long tube reinforces the inhalation of air through the nasopharynx and mouth

What prevents the trachea from collapsing?

cartilaginous rings

The trachea allows for slight __________ for food to pass through the esophagus

compression

What is the larynx?

Voice box within the trachea

The trachea will split into the left and right ___________. What will this lead to?

bronchus, left and right lungs

In the fetal pig, the right lung is ___ lobes and the left lung is ___ lobes.

4, 2

In humans, the right lung is ___ lobes and the left lung is ___ lobes.

3, 2

What is the diaphragm?

Thin, muscular tissue underneath the lungs

Inside the lungs, the two primary bronchi are subdivided into secondary branches called what?

bronchioles

Continued branching of the bronchioles leads to the _____

Alveoli