2025 Anatomy Exam 2 Flashcards
Lectures 5-8: Vascular Anatomy, Blood, Lymphatics, GI, Endocrine, Reproductive
What are the primary substances transported by the cardiovascular system?
- Nutrients
- Oxygen and carbon dioxide
- Enzymes and hormones
- Ions
- Metabolic wastes
- Leukocytes
List some functions of the cardiovascular system.
- Stabilization of body temperature
- Prevention of loss of body fluids
- Stabilization of pH
- Electrolyte balance
What are the two main components of blood?
- Plasma
- Formed elements
Define erythrocytes.
Red blood cells that transport oxygen and carbon dioxide.
What is the function of leukocytes?
To function in the immune system.
What role do platelets play in the blood?
Involved in blood clotting.
Formerly called thrombocytes.
What percentage of plasma is made up of water?
92%
What are the major plasma proteins and their percentages?
- Albumins (60%)
- Globulins (35%)
- Fibrinogen (4%)
- Regulatory proteins (< 1%)
What is the primary function of albumins?
Contribute to osmotic pressure and transport lipids and steroid hormones.
What is the primary function of globulins?
Transport ions, hormones, lipids, and function in immune response.
What is the role of fibrinogen in the blood?
Essential component of clotting system; converts to insoluble fibrin.
What is the normal pH range of blood?
7.35–7.45
Whole Blood Part
Plasma
Packed Cells
Mostly erythrocytes (>99.9%) with fewer leukocytes (<0.1%)
Platelets
What is the hematocrit reading?
Percentage of whole blood occupied by formed elements.
What is the average volume of blood in males and females?
- Males: 4–6 liters
- Females: 4–5 liters
What is the life span of red blood cells (RBCs)?
About 120 days.
What is the significance of RBCs lacking a nucleus?
- Allows flexibility in circulation
- More room for hemoglobin
What is hemoglobin and its primary function?
A protein responsible for transporting oxygen and carbon dioxide.
What are the major blood types based on surface antigens?
- Agglutinogen A
- Agglutinogen B
- Agglutinogen D
People with type A blood have which agglutinogen and agglutinin?
- Agglutinogen A
- Agglutinin B
Fill in the blank: Blood with clotting proteins removed is called _______.
serum
True or False: Carbon dioxide concentration is higher in plasma than in interstitial fluid.
False
What type of agglutinogen do people with type A blood have?
A agglutinogen
People with type A blood also have anti-B agglutinin in their plasma.
What type of agglutinogen do people with type B blood have?
B agglutinogen
People with type B blood also have anti-A agglutinin in their plasma.
What agglutinogens are present in type AB blood?
Agglutinogen A and agglutinogen B
People with type AB blood have no agglutinin in their plasma.
What agglutinogens are present in type O blood?
Neither agglutinogen A nor B
People with type O blood have both types of agglutinins (anti-A and anti-B) in their plasma.
What antigen do people with Rh positive blood have?
Rh factor (Rh antigen)
People with Rh negative blood do not have the Rh factor.
What happens during agglutination?
Clumping of red blood cells occurs
This can lead to hemolysis if incompatible blood types are mixed.
What is the normal range of neutrophils in white blood cells?
50–70 percent
Granular Leukocytes
Neutrophils are typically the first white blood cells to respond to bacterial infections.
What is the function of eosinophils?
Reduce inflammation and attack foreign substances
2-4%
Granular Leukocytes
Eosinophils are particularly involved in allergic reactions and parasitic infections.
What do basophils release?
Histamine and heparin
<1%
Granular Leukocytes
Histamine dilates blood vessels, and heparin prevents abnormal blood clotting.
What is the primary function of monocytes?
Phagocytosis and attracting other phagocytic cells
2-8%
Agranular Leukocytes
Monocytes can differentiate into macrophages and dendritic cells.
What is the normal range of lymphocytes in white blood cells?
20–30 percent
Agranular Leukocytes
Lymphocytes are responsible for specific immunity.
What are the three types of lymphocytes?
T cells, B cells, NK cells
Each type of lymphocyte has a specific role in the immune response.
What is the process of blood formation called?
Hemopoiesis
Hemopoiesis begins with hematopoietic stem cells.
What do myeloid stem cells differentiate into?
Erythrocytes, platelets, basophils, eosinophils, neutrophils, monocytes
This process is known as leukopoiesis.
What do lymphatic stem cells differentiate into?
Lymphocytes, B lymphocytes, T lymphocytes, NK cells
This process is known as lymphopoiesis.
What is thrombocytopenia?
Lower than normal number of platelets
Thrombocytosis refers to a higher than normal number of platelets.
What is the role of platelets in hemostasis?
Involved in blood clotting and forming a platelet plug
Platelets release chemicals to initiate the clotting process.
Blood Donor Matrix
True or False: Type A blood can receive type B blood safely.
False
Type A blood has anti-B antibodies that will react with type B agglutinogens.
Fill in the blank: Type O (packed cells) donor can donate to type _____ patient.
O- = all blood types
O+ = all blood types that are +
Type O does not have any agglutinogens to activate the patient’s agglutinins.
What is the typical lifespan of white blood cells?
Usually a few days
White blood cells multiply when the body is compromised.
What is the function of leukocytes in response to infection?
They multiply and follow chemicals released by body cells
This process is known as chemotaxis.
What is the primary site of hematopoiesis in adults?
Red bone marrow
Hematopoiesis is the process of blood cell formation.
What type of tissue is blood classified as?
Connective tissue
What is the role of erythropoietin (EPO)?
Stimulates erythropoiesis
EPO is produced by the kidneys and liver during hypoxia.
What are the stages of erythrocyte development?
- Proerythroblast
- Erythroblast
- Reticulocyte
- Erythrocyte
True or False: Yellow marrow can be converted to red marrow under some conditions.
True
What are the types of granulocytes?
- Neutrophils
- Eosinophils
- Basophils
What is the significance of reticulocytes in erythropoiesis?
They are immature erythrocytes released into the bloodstream.
What differentiates into plasma cells?
B cells
What types of cells do lymphoid stem cells differentiate into?
- B cells
- T cells
- NK cells
What are the two key types of stem cells involved in hemopoiesis?
- Hematopoietic stem cells
- Lymphoid stem cells
True or False: CSFs (Colony Stimulating Factors) are involved in the regulation of blood cell production.
True
What are the two groups of blood vessels?
Pulmonary circuit and systemic circuit
What does the pulmonary circuit do?
Blood goes to and from the lungs
What does the systemic circuit do?
Blood goes to the rest of the body and back to the heart
How do blood vessels work during each heartbeat?
Blood goes to both circuits at the same time
What are the three layers of blood vessel walls?
Adventitia, media, intima
Walls of Biggest Blood Vessels Have
vasa vasorum
What is the intima layer also called?
Tunica intima
Inner most
Composed of endothelium
Internal Elastic Membrane
What is the media layer also called?
Tunica media
Middle Layer
Smooth Muscle
Vasoconstriction and Vasodilation
External Elastic Membrane
What is the adventitia layer also called?
Tunica adventitia
Outermost
Anchor the blood vessel
How do the walls of arteries compare to those of veins?
Walls of arteries are thicker than veins
What shape do arteries maintain when cut?
Circular shape
What feature helps veins prevent backflow of blood?
One-way valves
What are the characteristics of large veins?
Average luminal diameter is about 2 cm, wall thickness is about 2 mm
What are elastic arteries known for?
Being very resilient and containing elastic membranes
What is the average luminal diameter of elastic arteries?
About 1.5 cm
What do muscular arteries control?
Vessel diameter under control of autonomic nervous system
What is the average luminal diameter of muscular arteries?
About 4 mm
What are arterioles?
Smallest arteries, around 30 microns in diameter
What is the primary function of capillaries?
Nutrient/waste exchange between blood and tissues
What are the three types of capillaries?
- Continuous
Endothelial lining is complete
Most Common - Fenestrated
Endothelial lining is not complete
Have Pores - Sinusoids
aka Discontinuous Capillaries
Endothelial lining is not Complete
Have Pores
What is a capillary bed?
An interconnected network of capillaries
What are collateral arteries?
Arteries that fuse to supply a specific area
What is an arteriovenous anastomosis?
A direct connection between arterioles and venules
What is the structure of medium-sized veins?
Adventitia is the largest layer, contains elastic fibers, and has one-way valves
What assists blood in veins returning to the heart from the lower extremities?
Skeletal muscles and venous valves
True or False: Large veins have valves.
False
Flow of Blood
Large Vein
Medium Sized Vein
Venule
Fenestrated Capillary
Elastic Artery
Muscular Artery
Arteriole
Continuous Capillary
What aids blood flow through the venae cavae back to the heart?
Changes in thoracic pressure
What helps propel blood back to the heart from the lower extremities?
Skeletal muscles of the legs
Skeletal muscles contract and create pressure to move blood upward against gravity.
What is the function of venous valves?
Aids in the one-way flow of blood
Venous valves prevent backflow and ensure blood returns to the heart.
What percentage of total blood volume do veins contain?
65–70 percent
Veins are known to have a larger capacity than arteries.
What are veins referred to as due to their capacity?
Capacitance vessels
Veins can expand significantly to accommodate varying blood volumes.
What is venoconstriction?
Shifts blood toward the arterial side of circulation
This mechanism helps regulate blood distribution in the body.
What is the primary difference in blood pressure between the pulmonary and systemic circuits?
Blood pressure is lower in the pulmonary circuit
This difference affects the structure of the vessel walls.
What is the pathway of oxygen-poor blood in the pulmonary circuit?
Right ventricle → pulmonary valve → pulmonary trunk → pulmonary arteries → lungs
Blood drops off carbon dioxide and picks up oxygen in the lungs.
Where does oxygenated blood return to the heart from the lungs?
Via the pulmonary veins
This blood enters the left atrium of the heart.
What does the left side of the heart supply?
Systemic circulation
This side pumps oxygenated blood to the rest of the body.
What are the branches of the aortic arch?
- Brachiocephalic trunk
- Left common carotid artery
- Left subclavian artery
These branches supply blood to the arms and head.
What do the common carotid arteries divide into?
- Internal carotids
- External carotids
These arteries supply blood to the brain and face, respectively.
What is the function of the carotid sinus?
Contains baroreceptors and chemoreceptors
The carotid sinus helps regulate blood pressure and chemistry.
What arteries supply the brain?
- Internal carotid arteries
- Vertebral arteries
These arteries ensure adequate blood supply to brain structures.
True or False: Blood pressure in the systemic circuit is higher than in the pulmonary circuit.
True
This higher pressure is necessary for blood to travel longer distances.
Fill in the blank: The _______ arteries supply blood to the eyes.
Ophthalmic artery
The ophthalmic artery is a branch of the internal carotid artery.
What is the main artery supplying blood to the brain?
The Aorta
The Aorta branches into the carotid and vertebral arteries which supply the brain.
What two branches does the thoracic aorta divide into?
Visceral branches and parietal branches
Name one type of visceral branch of the thoracic aorta.
Bronchial arteries
Other visceral branches include pericardial, mediastinal, and esophageal arteries.
True or False: The inferior vena cava returns blood from the upper extremities to the heart.
False
The superior vena cava returns blood from the upper extremities.
What is the main function of systemic veins?
Collect blood from body tissues and return it to the heart
Where does blood from the lower extremities return to the heart?
Inferior vena cava to the right atrium
What is unique about venous drainage in the neck and limbs?
They have both deep and superficial veins
What does the superior vena cava receive blood from?
Head, neck, chest, shoulders, upper limbs
What vein drains the superficial veins of the head and neck?
External jugular vein
The external jugular vein receives blood from the temporal and maxillary veins.
List the sequence of veins that blood from the hands returns to the heart.
- Digital veins
- Superficial palmar veins
- Palmar venous arches
- Cephalic vein
- Subclavian vein
- Brachiocephalic vein
- Superior vena cava
What sequence of veins returns blood from the feet to the heart?
- Plantar veins
- Ventral plantar arches
- Anterior tibial vein
- Posterior tibial vein
- Fibular vein
- Popliteal vein
- Femoral vein
- External iliac vein
- Common iliac vein
- Inferior vena cava
True or False: The fetal cardiovascular system has functional lungs.
False
The fetal lungs are nonfunctional, and all nutritional and respiratory needs are met via the placenta.
What are the two ‘short circuits’ used in fetal heart circulation to bypass the lungs?
- Foramen ovale
- Ductus arteriosus
Fill in the blank: The _______ is a shunt that allows blood to bypass the fetal liver.
ductus venosus
What happens to the ductus arteriosus upon birth?
It contracts and forms the ligamentum arteriosum.
What structure closes due to increased pressure in the left atrium after birth?
Foramen ovale
This eventually forms the fossa ovalis in the adult heart.
What do the internal iliac arteries supply?
Pelvic organs and gluteal region
The internal iliac arteries are crucial for supplying blood to various structures in the pelvis.
What type of blood is carried by the arteries in the human body?
Oxygen-rich blood
Most arteries carry oxygen-rich blood, except for the pulmonary arteries which carry oxygen-poor blood.
What type of blood is carried by the veins in the human body?
Oxygen-poor blood
Veins generally return deoxygenated blood to the heart, except for the pulmonary veins which carry oxygen-rich blood.
What is the primary change in the cardiovascular system at birth?
Smooth muscles of the ductus arteriosus contract
This contraction leads to the formation of the ligamentum arteriosum in adults.
What happens to the foramen ovale at birth?
Closes due to increased pressure in the left atrium
The closure of the foramen ovale forms the fossa ovalis in the adult heart.
True or False: Atherosclerosis affects only the arteries.
True
Atherosclerosis primarily refers to the buildup of plaques in the arterial walls.
Fill in the blank: The ductus arteriosus becomes the _______ after birth.
ligamentum arteriosum
This transformation is a key event in the transition from fetal to postnatal circulation.
The lymphatic system consists of
Lymph
Consists of:
Interstitial fluid
Lymphocytes
Macrophages
Lymphatic vessels
Consists of:
Pass through lymphatic tissue and organs
Deliver lymph to venous circulation
Lymphatic tissues and organs
Consists of:
Primary lymphatic structures
Thymus
Red bone marrow
Secondary lymphatic structures
Tonsils
Lymph nodes
Axillary, lumbar, pelvic, inguinal
Spleen
Mucosa-associated lymphoid tissue
Functions of Lymphatic System
Produce, maintain, and distribute lymphocytes
Maintain normal blood volume and the normal composition of the interstitial fluid
Provide an alternative route for the transport of
Hormones
Nutrients
Waste
Primary lymphatic structures
Cause differentiation of lymphocytes resulting in:
T cells, B cells, and NK cells
Secondary lymphatic structures
Considered to be the “front line” of defense
Consist of lymphocytes and more B cells to battle infectious agents
How Lymphatic System Helps Maintain BP
The maintenance of normal blood volume and chemical composition of the interstitial fluid
The blood pressure in capillaries is about 35 mm Hg
This pressure forces solutes and waste out of the plasma into the interstitial fluid area
Some interstitial fluid enters the lymphatic system
The lymphatic system eventually returns fluid to the venous system
Lymph
Consists of:
Interstitial Fluid
Lymphocytes
Macrophages
Fluid is similar to plasma, but lack proteins
Found only in the CLOSED Lymphatic vessels
Transparent, colorless or slightly yellow, watery
Lymphocytes increase in number after the passage of the lymph through lymphoid tissue (lymph glands)
Lymphocytes
Lymphocytes are the primary cells of the lymphatic system
They respond to:
Invading bacteria and viruses
Abnormal body cells such as cancer cells
Foreign proteins such as toxins released by some bacteria
Travel throughout body
Exit bloodstream to enter interstitial spaces
Re-enter bloodstream via lymphatic vessels
Types of Lymphocytes: T Cells
T Cells
Originate in the bone marrow but travel to the thymus gland and become activated (immunocompetent) by thymosin
Mature T cells leave thymus and migrate to red bone marrow, spleen, and other lymphatic tissues
Different types of T cells
Cytotoxic T cells
Attack foreign cells and viruses
Helper T cells
Stimulate both T and B cells
Enhance antibody production
Regulatory T cells
Moderate immune response
Memory T cells
Become activated if the same antigen appears in the body at a later date
Types of Lymphocytes: B Cells
B Cells
Originate and become immunocompetent in the bone marrow
Mature B cells enter bloodstream and migrate to peripheral tissues
Can differentiate to form:
Plasma cells
Produce antibodies that react with antigens
Antibodies are also called immunoglobulins
Memory B cells
Become activated if the same antigen appears at a later date
Types of Lymphocytes: NK Cells
NK Cells
Attack foreign cells
Attack normal cells that are infected with viruses
Attack cancer cells
Immune Response
There are two response mechanisms
Cell-mediated immunity
T cells directly attach to the pathogen
Antibody-mediated immunity
Pathogen is attacked by antibodies produced by B cells
Antigens attacked by macrophages
Presented to T Cells to differentiate
We are Immunocompetence = ability to recognize antigens (non-self)
Lymphocytes produced in Bone Marrow and Thymus and peripheral lymph tissue
Lymphatic Capillaries
Comparisons to vascular capillaries
Lymphatic capillaries are larger in diameter
Lymphatic capillaries have thinner walls
Lymphatic capillaries have an irregular outline
Lymphatic capillaries have anchoring filaments that connect to the surrounding connective tissue to keep the capillaries open
Lymphatic capillaries have greater permeability
Have 1-way valves in them to accept interstitial fluid, preventing back flow
Larger Lymphatic Vessels
Called Lymphatic Ducts
Comparing larger lymphatics to veins
Lymphatic vessels have thinner walls
Lymphatic vessels have larger lumens
Lymphatic vessels do not have easily identifiable tunics
Larger lymphatic vessels have valves just like most veins have
Pressure in the lymphatic vessels is lower than the pressure in the veins
Valves prevent the backflow of lymph
Skeletal muscles contract to help propel lymph
Inhalation decreases thoracic pressure, which helps to move lymph toward the venous system (subclavians)
Empty into the Thoric Duct and Right Lymphatic Duct
Structure of Lymphatic Vessels
Lacteals - Lymphatic Capillaries
Found in GI Tract
Pick up dietary lipids and lipid-soluble vitamins in addition to interstitial fluid
This fluid is milky-colored and called Chyle
Interrupted at intervals by constrictions, which give them a knotted appearance
Found nearly throughout the whole body
Structure of the Lymphatic Vessel
Internal Coat
Slightly Elastic
Elongated endothelial cells
Middle Coat
Smooth muscle
Fine Elastic Fibers
External Coat
Connective tissue
Some smooth muscle fibers
Protective
Valves of Lymphatics
Pressure is lower than that of veins
Intraluminal valves prevent the back flow of lymph
Skeletal muscle contraction helps movement
Inhalation decreases thoracic pressure, helping move lymph toward venous system (subclavian)
The flow of the subclavian veins draws lymph into it, exercise helps with lymphatic return
Major Lymph Collecting Vessels
Two Kinds:
Superficial Lymphatics
Found in Subcutaneous layer
Mucous lining of the digestive, respiratory, urinary and reproductive tracts
Serous lining of the various cavities
Deep Lymphatics
Collect from the skeletal muscle and tissue of the lymphatic trunks
5 Major
Lumbar
Intestinal
Subclavian
Bronchomediastinal
Jugular
Flow of Lymph
Lymphatic Capillaries
Lymphatic Vessels
Lymphatic Nodes
Collecting Ducts (5 major)
jugular, subclavian, bronchomediastinal, lumbar, and intestinal… intercostal branches too
Thoracic Duct and Right Lymphatic Duct
Subclavian Vein/Bloodstream
Thoracic is left subclavian
Right Lymphatic is right subclavian
Thoracic Duct
Begins as a saclike structure called the cisterna chyli
Drains into left subclavian
Drains lymph inferior to the diaphragm
Drains lymph from left arm, left side of torso, left side of neck and left side of head
About 38 to 45 cm and extends from the second lumbar vertebra to the root of the neck
Begins in the abdomen by a triangular dilation (cisterna chyli), which is on front of the body of the 2nd lumbar vertebra, to the right side and behind the aorta, by the right cruss of the diaphragm
Right Lymphatic Duct
Does not have a swelling like Thoracic Duct (cisterna chyli)
Drains into right subclavian
Drains lymph from:
right arm, right side of the torso, right side of neck, right side of the head
Much Shorter in length
From the root of the neck to the ending in the right subclavian vein (runs along the scalenus anterior muscle)
Lymphoid Tissue vs Nodules
Lymphatic tissue characteristics
Tissue dominated by lymphocytes
Lymphocytes are loosely aggregated within connective tissue
Lymphatic nodule characteristics
Lymphocytes aggregated within a supporting framework of reticular fibers
Nodules have a germinal center, which contains the lymphocytes
Both lymphatic tissue and lymphatic nodules are diffuse lymphatic tissues with capsule
Types of Lymph Nodules
Types of nodules
Mucosa-associated lymphoid tissue (MALT)
Lymphatic nodules associated with the digestive tract
Tonsils
There are five sets of tonsils
One pharyngeal tonsil
Two palatine tonsils
Two lingual tonsils
Aggregated lymphoid nodules (Peyer’s patches and appendix)
Lymphatic nodules associated with the small intestine
Lymphoid Organs
Separated from surrounding tissue by a fibrous capsule
Lymphatic organs include:
Lymph nodes
Thymus gland
Spleen
Lymph Nodes
1–25 mm in diameter
Surrounded by fibrous connective tissue capsule
Situated along the lymphatic system and lacteal vessels
Widely distributed throughout the body, but concentrated in regions where body is more susceptible to injury or invasion
Cervical Region
Axillary
Breasts
Abdominal
Inguinal (one superficial and one deep)
Think of them as biological filters dispersed along the path of the lymphatic system
Only organs that filter lymph
Reticular tissue cells (like network of cotton fibers)
Respond to antigens
Structure of Lymph Nodes
Bean Shaped
Lymph nodes consist of:
Hilum, where blood vessels and nerves enter and exit
Capsule with afferent vessels
Subcapsular space
Many dendritic cells
Outer cortex
Includes germinal center
Contains B cells
Paracortex
Contains T cells
Medulla
Contains B cells and macrophages
Medullary cords
Hilum with efferent vessels, blood vessels, and nerves
Efferent Lymph Vessel = emerges from the gland, commence from the lymph sinus of the medullary portion
Afferent Lymph Vessel = enters the organ at different parts of the periphery
The Thymus
Refines T Cells… if a faulty T Cell fighting our tissue, gets rid of it
Lies posterior to the manubrium of the sternum
Reaches its greatest size relative to body size by age 1 or 2
Reaches maximum size by puberty
Diminishes in size after puberty
Consists of two thymic lobes (left and right)
Consists of numerous lobules (about 2 mm in width) separated by septa
Consists of a cortex and a medulla
The cortex consists of:
Stem cells that differentiate to form T cells
Mature T cells migrate to the medulla
The medulla consists of:
T cells that remain inactive until they enter circulation
Thymic corpuscles (function is unknown)
Epithelial reticular cells are scattered throughout the thymus
Produce thymic hormones such as thymosin
The Spleen
Largest lymphatic organ (12 cm in length)
Located on the left edge of the stomach
Attached to the stomach via the gastrosplenic ligament
Surfaces of the Spleen
Consists of the following areas or regions
Diaphragmatic surface
Visceral surface
The visceral surface contains the hilum
Exhibits indentations/impressions of organs
Gastric area
Renal area
Blood supply enters via splenic artery, venous blood drains to splenic vein
The spleen consists of:
Capsule
Red pulp
Contains large quantities of red blood cells and macrophages
Macrophages identify and engulf damaged or infected red blood cells
White pulp
Forms lymphoid nodules
Can respond to antigens or pathogens in the blood
Functions of Spleen
Initiates a immune response when antigens found in blood (white pulp)
Serves a reservoir for RBCs and Platelets (red pulp)
Phagocytizes old, defective RBCs and Platelets (red pulp) and bacteria
Aging of the Lymphatic System
As we age:
T cells become less responsive to antigens
Number of helper T cells declines
B cells then become less responsive as well
Age increases susceptibility to infections and cancer
Thymus gland diminishes in size
Digestive System Intro
The digestive system consists of:
The digestive tract
Accessory organs of digestion
Digestive tract
Mouth
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
Accessory organs of the digestive tract
Teeth
Tongue
Salivary glands
Pancreas
Liver (largest organ in the body)
Gallbladder
Functions of Digestive System
Functions of the digestive system
Ingestion
Mechanical processing
Digestion
Secretion
Absorption
Excretion
Compaction
Defecation
Histological Organization of the Digestive Tract
There are four major layers of the digestive tract:
The mucosa
The submucosa
The muscular layer
The serosa (the peritoneum, what covers small intestine is called mesentery)
The Mucosa
The inner lining of the digestive tract
This is a mucous membrane
The mucosal epithelium is either a stratified or simple epithelium
Oral cavity, pharynx, and esophagus are lined with nonkeratinized stratified squamous cells (resist stress and abrasion)
Stomach, small intestine, and large intestine are lined with simple columnar cells (for secretion and absorption)
The mucosa of the small intestine makes up circular folds, or plicae circulares
Plicae circulares increase the surface area for increased absorption
Lamina propria
Contains blood vessels, nerves, smooth muscle, and lymphatic vessels
Muscularis mucosae
Narrow band of smooth muscle at the border of the mucosa
Mucosa cells have microvilli arranged in/on villi within the structure of circular fold
The Submucosa
Deep to the mucosa
Areolar connective tissue
Large blood vessels and lymphatics are in this layer
Submucosal neural plexuses innervate the mucosa
Consists of sensory neurons
Consists of parasympathetic ganglia
Consists of sympathetic postganglionic fibers
The Muscular Layer
Also called the muscularis externa
Deep to the the submucosa
Dominated by smooth muscle fibers
In some locations forms sphincters or valves
Innervated by myenteric neural plexus
This is a network of parasympathetic ganglia and sympathetic postganglionic fibers
The Serosa
Outermost layer of the digestive system
Only within the peritoneal cavity
Not found in pharynx, esophagus, and rectum
These structures covered by fibrous adventitia
The Peritoneum
The serosa (visceral peritoneum) is continuous with the parietal peritoneum
Serous fluid lubricates the serosal surfaces
The abdominal organs lie within the peritoneal cavity or the abdominal cavity
Intraperitoneal organs
stomach, spleen, liver, and parts of the duodenum, jejunum, ileum, transverse colon, and sigmoid colon
Retroperitoneal organs
Suprarenal (adrenal) gland
Aorta and IVC
Duodenum
Pancreas
Ureter
Colon
Kidney
Esophagus
Rectum
*SAD PUCKER
Secondarily retroperitoneal organs
Intraperitoneal organs
Organs that lie within the peritoneal cavity
Organs are surrounded completely by the visceral peritoneum
Examples:
Stomach
Liver
Ileum
Retroperitoneal organs
Organs are covered by the visceral peritoneum on their anterior surface
These organs lie outside the visceral peritoneum
Examples:
Kidneys
Ureters
Abdominal aorta
Pancreas
Secondarily retroperitoneal organs
These organs form as intraperitoneal but soon become retroperitoneal
The change occurs during embryonic development as the associated visceral peritoneum fuses with the opposing parietal peritoneum
Examples are:
Pancreas
Duodenum
The Peritoneum: Mesenteries
Mesenteries
These are fused double sheets of peritoneal membrane
Function:
Stabilize the position of organs
Provide route for the passage of blood vessels, nerves, and lymphatics to and from the digestive tract
All of the small intestine but the duodenum is suspended in a sheet of mesentery called the mesentery proper
Large intestine suspended by three mesenteries:
Mesocolon
Mesentery attached to the large intestine
Transverse mesocolon
Mesentery attached to the transverse colon
Sigmoid mesocolon
Mesentery attached to the sigmoid colon
Fusion fascia
The ascending colon, descending colon, and rectum are attached to the posterior abdominal wall via this fused mesentery
Lesser omentum
Lies between the stomach and the liver
Greater omentum
Extends from the stomach and covers the rest of the abdominal organs on the anterior surface
Contains thick layer of adipose
Functions as an energy reserve and as insulation
Mesenteries Pic
Retroperitoneal organs after taking away peritoneum
Mesenteries Lateral Pic
The Oral Cavity
Structures within the oral cavity
Tongue
Uvula (close off path to nasopharynx so food doesn’t come out of nose)
Palatal arches
Salivary glands
Teeth
Anatomy of the Oral Cavity
Lined by oral mucosa
Consists of nonkeratinized stratified squamous cells
The oral mucosa is continuous with:
Lining of the cheeks
Lining of the lips
Lining of the gums, or gingivae
The space between cheeks, lips, and gums is called the oral vestibule
The roof of the oral cavity consists of:
Hard palate
This is the palatine process of the maxilla and the palatine bone
Separates the oral cavity from the nasal cavity
Soft palate
Separates the oral cavity from the nasopharynx
The soft palate makes up the palatoglossal arch, palatopharyngeal arch, and uvula
The floor of the oral cavity consists of:
The tongue
The oral cavity also houses the palatine tonsils
Lymphatic tissue
These lie between the palatoglossal and palatopharyngeal arches
They are lateral to the uvula
The space between the oral cavity and the pharynx is called the fauces
The Tongue
Has several functions
Mechanical digestion
Manipulation of food
Sensory analysis
Secretion of enzymes to aid in fat digestion
Movement for the formulation of words
Can be divided into different areas
Body
Anterior portion of the tongue
Root
Posterior portion of the tongue
Dorsum of the tongue
Superior portion of the tongue
Contains lingual papillae
Papillae contain the taste buds
Salivary Glands
There are three pairs of salivary glands
Parotid
Sublingual
Submandibular
Saliva consists of water, ions, buffers, and salivary amylase
All three pairs of glands produce salivary amylase
Partially digests carbohydrates
Regulation of the Salivary Glands
Secretions are controlled by the autonomic nervous system
Parasympathetic
Accelerates salivary secretions
Sympathetic
Unclear role
May reduce salivary secretions and change consistency of saliva
Salivary Glands (2)
Parotid salivary glands
The largest of the three salivary glands
Located on the lateral side of the face in the area of the ramus of the mandible
Parotid duct lies on the masseter muscle
Saliva drains to the mouth cavity via the parotid duct
Sublingual salivary glands
Covered by the mucous membrane of the floor of the mouth
Consist of numerous sublingual ducts that open along either side of the lingual frenulum
Submandibular salivary glands
Located on the floor of the mouth, deep into the mandible, inferior to the mylohyoid line
Submandibular ducts open on either side of the frenulum, posterior to the teeth
The Pharynx
Serves as a common passageway for food, liquid, and air
Pharyngeal muscles involved in swallowing:
Pharyngeal constrictors, push bolus towards esophagus (KNOW)
Palatopharyngeus
Stylopharyngeus
Palatal muscles
The Esophagus
This is a hollow muscular tube that extends from the pharynx region to the stomach
It is 25 cm long and 2 cm in diameter
Located posterior to the trachea
Enters the peritoneal cavity by passing through the esophageal hiatus of the diaphragm (T10)
Innervated by the vagus nerve (N X) from the esophageal plexus
Contains upper and lower esophageal sphincters
Top 1/3 you have straited muscle
Middle 1/3 is a mix
Lower 1/3 is smooth
The esophageal wall is made of:
Mucosa
Contains stratified, nonkeratinized squamous epithelium
Submucosa
Both mucosa and submucosa have large folds
Contains submucosal glands that produce mucus
Muscularis mucosae very thin or absent
Muscularis externa is mixed skeletal and smooth muscle
Both are under involuntary control
The esophagus does not have a serosa layer
Has fibrous adventitia (KNOW THIS)
The Stomach
The stomach performs three major functions:
Temporary storage of ingested food
Mechanical digestion of ingested food
Chemical digestion of ingested food
The end result is the production of chyme
Anatomy of the Stomach
The stomach is intraperitoneal and is located:
In the left hypochondriac, epigastric, and a portion of the umbilical and left lumbar regions
The stomach consists of:
Cardia
Fundus
Body
Pyloric part
Lesser curvature
Greater curvature
Omenta (greater and lesser)
Inside of Stomach
Gastric folds (gastric rugae)
Relaxed stomach: mucosa forms numerous muscular ridges
Folds permit expansion of the stomach
A stretched stomach exhibits less prominent folds
More as you get toward the Pyloric Part
Smooth muscle layers
Circular muscles
Longitudinal muscles
Oblique muscles
Mesenteries of the stomach
The mesenteries associated with the stomach are called the greater and lesser omentum
Greater omentum
Extends from the greater curvature of the stomach and drapes across the surface of the small intestine
Lesser omentum
Extending from the lesser curvature of the stomach to the liver is the hepatogastric ligament
Extending from the pylorus/duodenum region to the liver is the hepatoduodenal ligament
Blood Supply to the Stomach
There are three branches from the celiac trunk that supply the stomach
Left gastric artery
Supplies blood to the lesser curvature and cardia (KNOW THESE)
Splenic artery
Supplies blood to the fundus
Branches to form the left gastro-epiploic artery, which supplies the greater curvature
Common hepatic artery
Branches to form the right gastric, right gastro-epiploic, and gastroduodenal artery to supply the greater and lesser curvatures
KNOW
Superior Mesenteric Artery
Inferior Mesenteric Artery
Histology of the Stomach
Lined with simple columnar epithelium
Structures within the lining of the stomach
Gastric pits lead to gastric glands
Gastric pits and glands contain gastric secretory cells
Mucous surface cells
Mucous neck cells
Parietal cells
Chief cells
* In the stomach, parietal cells are responsible for secreting hydrochloric acid (HCl) and intrinsic factor, while chief cells secrete pepsinogen, the inactive form of the digestive enzyme pepsin; essentially, parietal cells create the acidic environment needed for digestion, while chief cells produce the digestive enzyme itself
Enteroendocrine cells
The Small Intestine
Regions of the small intestine
Approximately 6 meters (20 feet) in length and 2.5–4 cm (1–1.6 inches) in diameter
Consists of:
Duodenum
25 cm (10 inches) long; receives digestive enzymes from the pancreas, bile from the liver and gallbladder
Jejunum
2.5 m (8 feet) long; most of the digestion and absorption occurs in the jejunum
Ileum
3.5 m (12 feet) long
Histology of the Small Intestine
The lining contains:
Circular folds (plicae circulares)
Each plica consists of numerous intestinal villi
The apical surface of the epithelial mucosa has tiny microvilli
The plicae circulares, villi, and microvilli function to increase surface area for digestion and absorption
The lamina propria within each villus has capillaries
Villi absorb the digested nutrients from the lumen of the small intestine into the capillaries
KNOW THIS PICTURE
Histology of the Small Intestine
The Lamina Propria
The Lamina Propria
Each villus also contains a lacteal
Located within the lamina propria of the villus
Lacteals absorb material that cannot be absorbed by the capillaries
Examples would be large lipid-protein complexes
Small Intestine: Duodenum
Regional Specializations
The Duodenum
Contains duodenal papilla
Houses duodenal ampulla
Bile duct from liver/gallbladder and pancreatic duct from pancreas combine to form ampulla
Bile from the liver and gallbladder
Buffers and digestive enzymes from the pancreas
Smooth muscle of the hepatopancreatic sphincter controls release of secretions
Duodenal papilla
Small Intestine: Jejunum and Ileum
Regional Specializations
The Jejunum and Ileum
Jejunum
Has prominent plicae and villi
Most nutrient absorption occurs here
Ileum
Contains prominent lymphoid centers called aggregated lymphoid nodules (Peyer’s patches)
Plicae and villi reduced
The Large Intestine
Features of the large intestine
Approximately 1.5 m (5 feet) in length
Approximately 7.5 cm (3 inches) in diameter
Consists of three regions
Cecum
Colon
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum
Functions of the large intestine
Reabsorption of water
Results in compaction of waste (forms feces)
Absorption of vitamins produced by the housed bacteria
Storage of fecal material prior to defecation
Large Intestine: Cecum and Appendix
The cecum is intraperitoneal
The ileum connects to the medial surface of the cecum
An ileocecal valve regulates the movement of material from the ileum to the cecum
The vermiform appendix attaches to the cecum
Appendix is lymphatic tissue
The meso-appendix (mesentery) helps anchor the appendix to the ileum and the cecum
The Colon
The regions of the colon are:
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Waste material leaves the ileum and enters the cecum
Waste material goes “up” the ascending colon
Around the right colic flexure (hepatic flexure)
“Across” the transverse colon
Around the left colic flexure (splenic flexure)
“Down” the descending colon
To the sigmoid colon
Into the rectum
The wall of the colon has pouches called haustra that allow for expansion
Muscular layer is reduced to longitudinal bands of smooth muscle called teniae coli that aid in peristalsis and define the haustra
The serosa of the large intestine has numerous sacs of fat attached to and extending from the intestine called omental appendices
The Rectum
Temporarily stores waste matter (feces)
The last portion of the rectum is the anal canal
The anal canal contains anal columns
The anal canal ends at the anus
Internal anal sphincter is smooth muscle and involuntary
External anal sphincter is skeletal muscle and voluntary
The Liver
Accessory Organ
Largest Visceral Organ
The liver has many functions, including:
Metabolic regulation
Hematological regulation
Bile production
Anatomy of the Liver
Four lobes
Right lobe
Left lobe
Caudate lobe
Quadrate lobe
Anterior surface
Posterior surface
Falciform ligament
Marks the boundary between the left and right lobes
The inferior portion of the falciform ligament becomes thick and round and is called the round ligament
The round ligament used to be the fetal umbilical vein
The falciform ligament spreads on the surface of the liver attaching to the inferior side of the diaphragm
This spreading ligament is called the coronary ligament
The Liver Blood Supply
Blood Supply to the Liver
Two blood vessels supply the liver
Hepatic artery proper
Hepatic portal vein
Blood returns to inferior vena cava via hepatic veins
KNOW HOW ALL THE VEINS DUMP INTO HEPATIC PORTAL VEIN
Lobules of the Liver
Portal Triad
NEED TO YOUTUBE THIS MORE
Sinusoids consist of:
Sinusoid capillaries that lead to the central vein
Stellate macrophages (Kupffer cells): phagocytic cells of the liver
The Gallbladder
Accessory Organ
The gallbladder is divided into three regions
Fundus
Body
Neck
The cystic duct leads from the neck of the gallbladder to the common hepatic duct
KNOW THESE DUCTS MORE THAN WHAT IS ON SLIDE
Overview of Endocrine System
The main endocrine organs are:
Pituitary gland
Hypothalamus
Thyroid gland
Thymus gland
Important in kids, important for maturation of T-Cells
Suprarenal glands
Aka Adrenal Glands
Pineal gland (melatonin)
Parathyroid glands
Pancreas
Reproductive glands
Pituitary Gland and Hypothalamus
The pituitary gland is called the hypophysis
Attached to the hypothalamus via the infundibulum
Sits in the hypophyseal fossa of the sella turcica
Consists of two lobes
Adenohypophysis: anterior lobe releases nine peptide hormones
Rathke’s pouch – roof of developing mouth
Neurohypophysis: posterior lobe releases two peptide hormones produced in the hypothalamus
Pituitary Gland Blood Flow
The anterior pituitary (adenohypophysis) receives portal blood.
The posterior pituitary (neurohypophysis) receives arterial blood.
Portal system is a capillary between two venules
** YOUTUBE THIS MORE
Pituitary Gland Lobes
Pituitary Gland Important Areas
Pituitary Gland Hypophyseal Portal System
The Hypophyseal Portal System
Within the infundibulum is a plexus of capillaries
Capillaries are fenestrated
Regulatory hormones leave the hypothalamus and pass through the portal vessels to the adenohypophysis
The Thyroid Gland
Lies in the lower part of the neck at the level of the 5th cervical to the 1st thoracic vertebrae.
It is formed of 2 lobes connected by an isthmus.
Each lobe pyramidal in shape with an apex, a base & 3 surfaces (medial, lateral & posterior).
Each lobe is about 5 x 3 x 2 cm (length x width x thickness).
The apex is at the level of oblique line of thyroid cartilage of the larynx.
The base is at the level of the 4th or 5th tracheal ring.
The Thyroid Gland (Cadaver)
Autonomic innervation via
a. Cervical portion of sympathetic trunk
b. Parasympathetic fibers arise from Vagus X
The Thyroid Gland (Lateral)
Thyroid Gland (Cadaver 2)
Histology of Thyroid Gland (1)
Colloid is where the hormones are produced… which is within the follicular cells
Space between follicles is called medulla, within in there is C-cells (parafollicular cells) produce calcitonin
Histology of Thyroid Gland (2)
Blood Supply of Thyroid Gland
Blood Supply of Thyroid Gland (Venous System)
Thyroid Follicles
Thyroid Follicles (2)
Parathyroid Glands
Parathyroid Glands (2)
Parathyroid Glands (Cells)
Parathyroid Glands Histology
The Pancreas
The pancreas is highly vascularized
It has fenestrated capillaries
Has NO capsule
Head is supplied by the pancreaticoduodenal arteries
Tail is supplied by the pancreatic artery branches from the splenic artery
The pancreas is about 20–25 cm long
The head connects to the duodenum of the small intestine via the duodenal papilla. Pancreatic duct merges with the common bile duct.
The pointed tail extends toward the spleen
The pancreas is an exocrine and endocrine organ
The Pancreas Histology
Pancreatic islets (islet of Langerhans) are isolated cells within pancreas
A Cells - Glucagon
B Cells - Insulin
D Cells - Somatostatin
Pancreas with Histology
Located in epigastric & left hypochondriac regions
Dimensions:
1. 5 - 6” length x
2. 1-1/2” width x
3. 1/2 - 1” thick
Lies retroperitoneally at ~T-12/L-1 to L-3
Head fills concavity of duodenum
Body crosses left kidney
Tail reaches hilus of the spleen
Related anteriorly to transverse colon
Aorta, IVC lie posterior
Uncinate process:
Lies posterior to SMA and SMV
Lies anterior to aorta
Neck lies anterior to SMV, with pylorus just above
Regions of Pancreas
Venous Drainage of the Pancreas
Know the Celiac Artery and its branches…
GOOGLE THIS MORE
Hepatic Portal System, Need more GOOGLE THIS MORE
Arteries of Pancreas
Know the Celiac Artery and its branches…
GOOGLE THIS MORE
Hepatic Portal System, Need more GOOGLE THIS MORE
Head of Pancreas
The Adrenal Glands
Outer Section = Cortex (produce steroids)
Inside Section = Medulla
The Suprarenal (Adrenal) Glands
The suprarenal glands (adrenal glands) are located attached to the superior border of the kidneys
These glands are highly vascularized
Superior suprarenal arteries from the inferior phrenic arteries
Middle suprarenal arteries branch directly off of the aorta
Inferior suprarenal arteries from the renal arteries
Venous Drainage of Adrenal Glands
Left Adrenal Gland
Left suprarenal vein drains into the left renal vein
Right Adrenal Gland
Right suprarenal vein drains directly into the superior vena cava
Suprarenal Glands Cortex (Outer) and Medulla (Inner)
The suprarenal glands are made of two parts
Suprarenal medulla – catecholamines
Suprarenal cortex
The suprarenal cortex is made of three distinct zones
Zona glomerulosa - Mineralocorticoids
Zona fasciculate - Corticosteroids
Zona reticularis – Androgens
Main source for women
Histology of Adrenal Glands
Adrenal Glands (Cadaver)
Adrenal Medulla
Reproductive System
The reproductive system is designed to perpetuate the species
The reproductive system produces, stores, nourishes, and transports gametes
The male produces gametes called sperm
The female produces gametes called oocytes
The joining of a sperm cell and an oocyte is fertilization
Fertilization results in the formation of a zygote
Reproductive System Includes
Gonads
Testes/Ovaries that produce gametes and hormones
Reproductive tract
Ducts that receive, store, and transport gametes
Accessory glands
Secrete fluids
External genitalia
Perineal structures
Structures of Male Reproductive System
Principal structures of the male reproductive system are
Scrotum
Testis
Epididymis
Ductus deferens
Urethra
Glands
Seminal gland
Prostate gland
Bulbo-urethral gland
Penis
The Testes
Testes hang inside a pouch of skin called the scrotum, which is on the outside of the body
Testicle size
5 cm long
3 cm wide
2.5 cm thick
10–15 g
Descent of the Testes
During development, the testes form inside the abdominal cavity near the kidneys
Gubernaculum testis holds testes in place
As body growth proceeds, gubernaculum testis doesn’t elongate
Gubernaculum testis pulls testes inferiorly
Testes descend toward the scrotum by passing through the inguinal canals
The ductus deferens, blood vessels, lymphatics, and nerves remain bundled to the testes in the spermatic cords
Descent of the Testes
Testicle development requires a temperature of approximately 98.6ºF
Hence the development of the testicles within the abdominal cavity
Sperm development requires a temperature of approximately 96.6ºF
Hence the development of sperm cells outside the abdominal cavity
Teste Descent
The Spermatic Cords
The Spermatic Cords
Consist of:
Ductus deferens
Blood vessels
Deferential artery
Testicular artery
Pampiniform plexus of the testicular vein
Nerves
Ilioinguinal nerve
Genitofemoral nerve
Pass through narrow inguinal canals that connect scrotal chambers to peritoneal cavity
Know Cremaster and Dartos Muscle
The Scrotum
The Scrotum and the Position of the Testes
Divided into two chambers (scrotal cavities)
Chambers are separated by the raphe of the scrotum
Can be seen as thickened tissue that extends from the anus, across the scrotum, and along the anterior surface of the penis
Tunica vaginalis lines each cavity
A serous membrane that lines the cavity and reduces friction between opposing outer and inner serous layers
Muscles of the scrotum
Dartos muscle
Superficial smooth muscle
Contraction causes the wrinkling of the scrotal surface
Cremaster muscle
Contraction tenses the scrotal sac and pulls it closer to the body
The temperature for sperm development is 2ºF cooler than body temperature
Therefore, if the temperature is cold outside, the testes move closer to the abdomen to maintain the proper temperature
The Scrotum is Highly Vascularized and Sensory
The scrotum is highly vascularized by the:
Internal pudendal arteries
A branch from the internal iliac artery
External pudendal arteries
A branch from the femoral artery
Inferior epigastric arteries
A branch from the external iliac artery
The scrotum supplied with sensory and motor nerves from the:
Hypogastric plexus
Ilioinguinal nerves
Genitofemoral nerves
Pudendal nerves
Teste Histology Samples
Teste Structure
Tunica albuginea
A fibrous, connective tissue lining of the testes
Extends deep into the testes and forms septa
Septa converge toward the mediastinum of the testis
Mediastinum supports ducts that move material toward the epididymis
Tunica vaginalis
Serous tissue that surrounds the tunica albuginea and is continuous with the surrounding tissue of the epididymis
Purpose to limit friction during movement
Histology of the Testes
Histology of the Testes
The septa testes separate the testes into lobules
Each lobule contains tightly coiled seminiferous tubules
Each seminiferous tubule is approx. 80 cm long
Seminiferous tubules begin to uncoil leading to the straight tubules in the mediastinum area
The straight tubules interconnect with each other forming the rete testis within the mediastinum
Rete testis connects to the efferent ductules
Efferent ductules lead to the epididymis
There is a space between the coils of the seminiferous tubules
The cells within this space are the interstitial endocrine cells (Leydig cells)
Interstitial endocrine cells produce and release testosterone
Spermatogenesis and Meiosis
Spermatogenesis
Formation of sperm cells
Begins in the outer layer of the seminiferous tubules
Spermatogonia
Stem cells that will give rise to sperm cells
Formed during embryonic development but dormant until puberty
Meiosis
Cell division that produces haploid gametes
Spermiogenesis
Spermatids mature to form physically mature sperm cells
This maturation process is called spermiogenesis
During spermiogenesis, the spermatids are embedded in nurse cells (Sertoli cells)
Upon maturation, the spermatids (now sperm cells) enter into the lumen of the seminiferous tubules
Anatomy of a Sperm
Each spermatozoon has three areas
Head
Contains chromosomes
Contains acrosome consisting of enzymes
Enzyme, hyaluronidase, is necessary for fertilization of the egg
Middle piece (with the neck)
Contains mitochondria and centrioles
Tail
Only flagellum found in human body
Enables mobility of the sperm cell
Transportation of Sperm
Involved in the functional maturation, nourishment, storage, and transport of sperm
Consists of:
Epididymis
Ductus deferens
Urethra
Epididymis
The Epididymis
Fluid currents in the straight tubules move sperm cells to the epididymis
Sperm cells are physically but not functionally mature (can’t move independently yet)
The epididymis consists of three parts
Head
Receives spermatozoa via the efferent ducts
Body
Coiled tubes pass through the body
Tail
Tubes begin to uncoil to become a single tube called the ductus deferens
Ductus Deferens
Also called the vas deferens
Begins at the tail of the epididymis
Ascends into the abdominal cavity through the inguinal canal
Curves around the urinary bladder and the ureter then descends back toward and through the prostate gland
Before entering the prostate gland, the ductus deferens expands into the ampulla
The ampulla joins the excretory duct of the seminal gland to become the ejaculatory duct
The ejaculatory duct empties into the prostatic urethra
Posterior View of the Ductus Deferens
The Urethra
Divided to form three regions
Prostatic urethra
Extends from the urinary bladder through the prostate gland
Membranous urethra
Passes through muscular wall of pelvic cavity
Spongy urethra
Passes through the penis
Sometimes called the penile urethra
Accessory Glands
There are three glands associated with the male reproductive system
Seminal glands (or seminal vesicles)
Produce 60 percent of the semen volume
Seminal fluid consists of:
A high concentration of fructose
Prostaglandins
Clotting factors
Contents empty into the ductus deferens during ejaculation
Seminal fluids will enable sperm to become motile
Prostate
Prostatic fluid secreted into the prostatic urethra
Produces 20–30 percent of the semen volume
Weakly acidic
Secretions contain:
Enzymes that prevent sperm coagulation in vagina
Seminalplasmin
This is an antibiotic believed to prevent UTIs in males
Bulbo-urethral glands (or Cowper’s glands)
Paired glands located at the base of the penis
Produces 5 percent of the semen volume
Contents empty into the spongy urethra, immediately distal to body wall (end of membranous urethra)
Secretions
Consist of thick, sticky, alkaline mucus
Neutralize urinary acids that are remaining in the urethra
Provide lubrication for the tip of the penis
Semen
Semen
Each ejaculation releases 2 to 5 ml of semen
Ejaculate material consists of:
Sperm cells
Normal sperm count from 20–100 million per ml
Seminal fluid
60 percent from the seminal vesicles
30 percent from the prostate
5 percent from the bulbo-urethral glands
5 percent from the epididymis
Enzymes
Dissolves vaginal mucus and acts as an antibiotic
The Penis
Divided into three regions
Root
Attaches base of penis to the rami of the ischia
Body (shaft)
Consists of erectile tissue
Glans penis
The expanded distal end of the penis
Surrounds the external urethral orifice
Consists of three cylindrical columns of erectile tissue and blood vessels
Two posterior corpora cavernosa
One anterior corpus spongiosum
Cross Section of Penis
Female Reproductive System
Ovaries
Uterine tubes (Fallopian tubes)
Fimbriae
Uterus
Cervix
Vagina
External genitalia
Labia minora/majora
Breasts
The Vaginal Fornix, which there is two, are the little gaps between the vagina and cervix
Female Reproductive System (Cadaver)
Ligaments of the Female Reproductive System
Several ligaments support the ovaries, uterine tubes, and uterus
The broad ligament encloses ovaries, uterine tubes, and uterus
Mesosalpinx attaches to uterine tube
Mesovarium supports each ovary
Broad ligament is continuous with peritoneum and subdivides the pelvic cavity
Recto-uterine pouch
Vesico-uterine pouch
Ovarian, round, suspensory, and uterosacral ligaments also support the ovaries and uterus
Female Ligaments (Cadaver)
The Ovaries
Flattened oval measuring:
5 cm long
2.5 cm wide
8 mm thick
Stabilized by:
Mesovarium
Ovarian ligament
Suspensory ligament
Contains ovarian artery and vein
Connect to ovary at ovarian hilum
Consist of two stromal layers:
Cortex
Covered by germinal epithelium of simple cuboidal cells, which surrounds the fibrous tunica albuginea
Gamete production occurs in the cortex
Medulla
The Uterine Tubes
Hollow, muscular tube
Approximately 13 cm long
Consist of five regions
Fimbriae
Fingerlike projections that cover the ovary surface
Infundibulum
Expanded funnel near ovary
Inner lining of infundibulum contains cilia
Ampulla
Isthmus
Uterine part
Opens into the uterus
Histology of the Uterine Tubes
Consists of:
Ciliated and nonciliated columnar cells
Layers of smooth muscle
Combination of cilia and smooth muscle peristalsis moves oocyte/zygote
Successful fertilization:
Occurs 12–24 hours after ovulation
Occurs in the distal 2/3 of the uterine tube (ampulla region)
Creates a diploid zygote
The Uterus
Provides protection for the embryo
Provides nutritional support for the embryo
Provides a means to remove waste produced by the embryo
Overall size
Pear-shaped
7.5 cm long
5 cm diameter
30–40 g
Suspensory Ligaments of the Uterus
These are in addition to the various regions of the broad ligament
Uterosacral ligaments
Round ligaments
Cardinal ligaments
Anatomy of the Uterus
Gross Anatomy of the Uterus
Consists of:
Body
Fundus
Uterine cavity
Isthmus
Internal os
Cervix
Cervical canal
External os
The Vagina
An elastic, muscular tube
Extends from the cervix of the uterus to the external genitalia
Vagina is approximately 7.5–9 cm in length
Cervix projects from the uterus into the vaginal canal
The edges of the cervix form recesses called the vaginal fornix
The vagina is separated from the vestibule by an elastic epithelial fold called the hymen
Vaginal branches are the primary blood supply of the vagina
Serves three major functions
Passageway for elimination of menstrual fluids
Receives the penis and holds spermatozoa before they enter the uterus
Serves as a passageway for the fetus during vaginal birth
Contains a normal population of bacteria
Bacteria are provided nutrients found in the cervical mucus
The bacteria create an acid environment
This reduces the growth of many pathogenic organisms
This also reduces sperm mobility
Buffers found in seminal fluid counteract this acidity
Histology of the Vagina
Lined with stratified squamous epithelium
When relaxed, this tissue forms rugae
Lamina propria is thick and elastic
The muscular layer is continuous with the myometrium of the uterus
The External Genitalia
Vulva
Region enclosing external genitalia
Vestibule
The opening into the vagina surrounded by the labia minora
Moistened by greater and lesser vestibular glands
Clitoris
Contains erectile tissue and is covered by prepuce
Labia majora and mons pubis
Forms the lateral and superior edges of vestibule
The Breasts
Contain mammary glands
Mammary glands produce milk in a process called lactation
Mammary glands located within the pectoral fat pads of each breast
Each breast has a nipple surrounded by an areola
Areola contains large sebaceous glands
Remember a superficial and deep layer to breast. Most of the breast is adipose tissue
Mammary Glands
Mammary glands consist of:
Apocrine cells in lobules secrete milk into ducts
Lobular ducts combine and form a single lactiferous duct in each lobe
Lactiferous ducts expand to form lactiferous sinuses near nipple
15–20 lactiferous sinuses open onto the surface of each nipple
Suspensory ligaments support ducts, lobes, and lobules
High Missed Test Question - Vagina
Vestibule between labia minoria
Entrotuces opening to vaginal canal?
High Missed Test Question - Glans Penis
Glans penis is part of corpus spongiosum
High Missed Test Question - Mesenteric Arteries
Inferior Mesenteric Arteries - sigmoid colon
Superior Mesenteric Arteries - ?
High Missed Test Question - Esophagus Spinctors
Esophagus has upper and lower sphincter
Lower has no muscle band, acts as sphincter because of diaphragm
Upper is a True Spector, cricopharyngeal muscle
High Missed Test Question - Portal Vein made of
Actual Portal Vein is made by splenic and superior mesenteric vein
Inferior mesenteric vein Joins Splenic Vein
