Final Exam Guide for ANATOMY & PHYSIOLOGY II

Sac of skin and superficial fascia

Scrotum

When it's cold, the testes are pulled closer to the warm body wall. The scrotal skin wrinkles, decreasing its surface area and increasing its thickness to reduce heat loss.

General Functions of the Scrotum.

Dartos Muscles

Cremaster Muscles

Midline septum divides scrotum into two compartments, one of each testis:

"Skinned"

A layer of smooth muscle in the superficial fascia, wrinkles the scrotal skin.

Define the Dartos Muscles and what it's made of?

"Suspender"

Bands of skeletal muscle that arise from the internal oblique muscle of the trunk, elevate the testes

Define the Cremaster Muscles and what it's made of?

Tunica Vaginalis

Tunica Albuginea

Each testis is surrounded by two tunics, which are?

The maintenance of stable internal conditions despite external changes.

What is homeostasis?

Negative reduces/shuts off the original stimulus. Positive enhances/amplifies the original stimulus.

What is negative the difference between positive and negative feedback mechanisms?

Regulation of blood glucose by insulin.

Examples of Negative Feedback:

Oxytocin release during childbirth (contractions increase oxytocin, which increases contractions)

Examples of Positive Feedback:

Quick, brief, and targeted cells are usually muscle fibers or glands.

Know the system involved with feedback mechanism: Nervous system.

Slow, long lasting, target cells are varied (all over the body).

Know the system involved with the feedback mechanism: Endocrine system.

In the endocrine system, what is the hormonal regulation?

Parathyroid Hormone

Insulin

Growth Hormone

Adrenocorticotropic Hormone

What is the function of Parathyroid Hormone (PTH)?

Raises blood calcium levels by stimulating calcium release from bones and increasing calcium absorption in the gastrointestinal tract.

When is insulin secreted, and what does it do?

Secreted in response to high blood glucose levels (e.g., after a meal) and promotes the uptake of glucose into cells to lower blood sugar.

What are the effects of Growth Hormone (GH)?

Has anabolic effects, promoting protein synthesis and stimulating growth in bones and muscles.

What is the function of Adrenocorticotropic Hormone (ACTH)?

Stimulates the adrenal cortex to release its hormones, such as cortisol.

How do regulatory systems communicate in feedback mechanisms?

Through neural messages (quick and targeted) and chemical messages (hormones, slower but longer-lasting)

How do protein hormones exert their influence on target cells?

They use second messenger systems to relay signals inside the target cell.

What determines a cell's ability to respond to a hormone?

The presence of specific hormone receptors on or in the target cell.

What is the difference between endocrine and exocrine glands?

Endocrine glands secrete hormones directly into the bloodstream.

Exocrine glands release substances through ducts to the outside of the body or into the digestive system.

Exocrine Glands

Glands release substances through ducts to the outside of the body or into the digestive system.

Endocrine Glands

Glands secrete hormones directly into the bloodstream.

What is a hormone?

A chemical messenger secreted by glands that travels through the blood to regulate the activities of distant cells or organs.

What are the two types of hormone receptors?

Membrane-bound receptors

Intracellular receptors

Membrane-bound receptors

bind amino acid-based (protein) hormones

Intracellular receptors

bind steroid (lipid-soluble) hormones

Where are insulin and glucagon secreted?

By the pancreas (specifically, the islets of Langerhans)

What causes the secretion of glucagon?

secreted when blood glucose is low.

What causes the secretion of insulin?

secreted when blood glucose is high.

What are the effects of insulin?

lowers blood glucose by promoting uptake and storage

What are the effects of glucagon?

raises blood glucose by stimulating glycogen breakdown and gluconeogenesis.

What structures in the small intestine increase surface area for absorption?

Villi and microvilli.

What is the function of the serosa layer in the GI tract?

Attaches organs to the body wall.

What is the function of the mucosa layer in the GI tract?

Responsible for secretion and absorption.

What is deglutition?

swallowing

What structures involve deglutition?

mouth, pharynx, and esophagus—not the pylorus

What is mastication?

The physical process of chewing food.

What is catabolism in digestion?

The chemical breakdown of large molecules into smaller ones.

What does glycolysis produce?

Pyruvic acid and 2 ATP molecules per glucose.

What is gluconeogenesis?

The process of making glucose from non-carbohydrate sources, raising blood sugar levels.

What is glycogenolysis?

The breakdown of glycogen into glucose.

What do enzymes do?

Speed up chemical reactions without being consumed or changed.

Where does most nutrient absorption occur?

small intestine

What produces bile?

Hepatocytes in the liver.

Which stages of glucose catabolism require oxygen?

Krebs cycle and the electron transport chain.

What does the pineal gland do?

Produces melatonin to regulate sleep cycles.

What does thymosin do?

Helps in T-cell and immune system development.

What is the role of epinephrine?

Triggers the fight-or-flight response.

What is peristalsis?

Rhythmic contractions that move food through the esophagus and GI tract.

Where are pancreatic enzymes and bicarbonate secreted?

Into the duodenum of the small intestine.

What is the difference between anabolic and catabolic reactions?

Anabolic builds molecules; catabolic breaks them down.

What are the general functions of the digestive system?

Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation.

What are the six essential digestive processes?

Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation.

Define the peritoneum.

A double-layered serous membrane that lines the abdominal cavity and covers abdominal organs.

Secretes and absorbs

Mucosa

What are the four layers of the GI tract?

Mucosa

Submucosa

Muscularis externa

Serosa

Contains blood vessels, nerves

Submucosa

Responsible for peristalsis

Muscularis externa

Connects GI tract to surrounding structures

Serosa

Muscular contractions that move food

Peristalsis

Chewing

Mastication

Swallowing

Deglutition

What is anabolism?

Building complex molecules from simpler ones.

What is catabolism?

Breaking down molecules to release energy.

What is an enzyme and why is it important?

A biological catalyst that speeds up reactions without being used up.

What is ATP?

Adenosine triphosphate, the main energy currency of the cell.

How many ATP are produced in glycolysis per glucose molecule?

2 ATP.

How many total ATP are produced from glycolysis, Krebs cycle, and ETC per glucose molecule?

Approximately 36-38 ATP.

Why do we breathe in oxygen?

For the electron transport chain to produce ATP.

Where does the CO₂ we exhale come from?

From the Krebs cycle during cellular respiration.

What is the difference between the absorptive and post-absorptive state?

Absorptive: Nutrients are being absorbed and stored.

Post-absorptive: Stored nutrients are being used.

Nutrients are being absorbed and stored.

Absorptive

Stored nutrients are being used.

Post-absorptive

What muscles are involved in breathing?

The diaphragm and intercostal muscles.

What is the difference between intrapulmonary and atmospheric pressure?

Intrapulmonary pressure is the pressure within the lungs; breathing occurs when this pressure differs from atmospheric pressure.

Tthe pressure within the lungs

Intrapulmonary pressure

Breathing occurs when this pressure differs

Atmospheric pressure.

Where does gas exchange occur in the lungs?

Alveoli

What is external respiration?

Gas exchange between the lungs and blood.

What is internal respiration?

Gas exchange between the blood and body tissues.

What factors affect gas exchange?

Partial pressure gradients and gas solubility.

What is the role of CO₂ in regulating breathing?

CO₂ levels influence the pH of blood; high CO₂ increases breathing rate to expel excess

What is the role of O₂ in regulating breathing?

Low O₂ levels stimulate breathing, but CO₂ is the primary driver.

Where are the respiratory centers located in the brain?

In the medulla oblongata and pons.

What happens when the diaphragm contracts?

The diaphragm moves downward, increasing thoracic volume and causing inspiration

Describe the process of external respiration.

Gas exchange between alveoli and pulmonary capillaries—O₂ enters blood, CO₂ leaves.

How does CO₂ affect the urge to breathe?

(hypercapnia) strongly stimulate the respiratory centers to increase ventilation.

What is the major function of the respiratory system?

To supply the body with oxygen and remove carbon dioxide.

What are the four processes involved in respiration?

Pulmonary ventilation, external respiration, transport of gases, internal respiration.

How is oxygen transported in the blood?

Mainly bound to hemoglobin (98.5%), and a small amount dissolved in plasma.

Where is the partial pressure of oxygen high and low?

High in the alveoli and arteries; low in body tissues and veins.

How is carbon dioxide transported in the blood?

As bicarbonate ions (70%), bound to hemoglobin (20%), dissolved in plasma (10%).

Where is the partial pressure of CO₂ high and low?

High in tissues and veins; low in alveoli and arteries.

How does exercise affect respiratory rate and gas exchange?

Increases respiratory rate and efficiency of O₂/CO₂ exchange to meet metabolic demand.

What are the four chambers of the heart?

Right atrium

Right ventricle

Left atrium

Left ventricle

receives deoxygenated blood

Right atrium

pumps to lungs

Right ventricle

receives oxygenated blood

Left atrium

pumps to body

Left ventricle