Chapter 10: Human Organ Systems

Question 1

What is a bone?

Answer 1

A rigid, mineralized connective tissue that forms the skeleton of vertebrates, including humans.

Question 2

What are the roles of the musculoskeletal system?

Answer 2

1. support for the body.
2. protecting essential organs, such as the brain, spinal cord, heart, and lungs.
3. production of blood cells and storage of minerals, such as calcium and phosphate.

Question 3

What is the structure of the musculoskeletal system?

Answer 3

• The skeleton provides a structure for muscles to attach to, enabling us to move.
• We have muscles in our blood vessels, lining the walls of our stomach and intestines, and the heart.
• Muscles assist the bones in protecting internal organs and stabilizing joints.
• Muscles help us maintain a constant body temperature.

Question 4

How do bones maintain blood calcium levels?

Answer 4

Hormones play a crucial role in regulating bone formation and breakdown.
- Two key hormones, calcitonin, and parathyroid hormone, control blood calcium levels.
When blood calcium is elevated, it signals the thyroid gland to release calcitonin. This hormone boosts osteoblast activity to promote bone formation and inhibits osteoclasts, reducing calcium in the blood.
- Conversely, parathyroid glands secrete parathyroid hormone when calcium levels drop.

Question 5

How does bone formation occur at birth and throughout life?

Answer 5

• Bone growth begins several months before birth and continues into early adulthood (23–25 years of age).
• At birth, most of a baby’s bones are still made of cartilage. The osteoblasts on the cartilage frame lay down new bone tissue. - Spongy bone forms first, followed by the formation of compact bone.
• As a child grows, new bone tissue is laid down at a region called the epiphyseal plate, or growth plate.

Question 6

What does a skeletal muscle look like at the microscopic level?

Answer 6

striped pattern

Question 7

List and describe the three types of muscle.

Answer 7

• Skeletal muscle is attached to bones, allowing for movement.
• Smooth muscle is found in the intestines and helps with involuntary movements like digestion.
• The cardiac muscle is located in the heart and is essential for pumping blood and supporting circulation.

Question 8

How does muscle contraction occur?

Answer 8

• Z lines move closer together, shortening the sarcomere and triggering a neural impulse that stimulates the muscle cell.
• Chemicals are released, resulting in the release of calcium ions.
• Calcium binds to troponin, causing it to shift and pull, which exposes the myosin binding sites.
• Myosin attaches to actin, forming a cross-bridge.
• The removal of calcium causes tropomyosin to block the binding sites.
• If ATP is depleted, myosin heads lock onto actin, halting further power strokes, a condition known as rigor mortis.

Question 9

What is the basic structure and function of the nervous system?

Answer 9

The nervous system’s structure is a complex network of nerves and nerve cells (neurons) that carry out messages and signals from the brain and spinal cord to the rest of the body, enabling us to react. The function of the nervous system is to help us coordinate our movements and for us to have reflexes.

Question 10

What is the basic structure and function of the respiratory system?

Question 11

What is the basic structure and function of the digestive system?

Question 12

What is the basic structure and function of the urinary system?

Question 13

What is the basic structure and funciton of the reproductive system?

Question 14

How is a nerve impulse transmitted?

Question 15

What is the path of blood through the heart and lungs?

Answer 15

Essentially, the circulatory system forms a double-loop system. Deoxygenated blood enters the heart through the superior and
inferior vena cava veins, passes through the right atrium and right ventricle, exits the heart through the pulmonary artery, and heads toward the lungs. After oxygenation in the alveoli in the lungs, the blood returns to the heart and enters through the pulmonary vein. It passes through the left atrium and left ventricle, exits the heart through the aorta, travels to various parts of the body. It then returns to the heart.

Question 16

What is the digestive process of food, staring in the mouth until it exits the anus?

Question 17

How is urine formed?

Question 18

What are the early stages of human development?

Answer 18

HAVE TO

Question 19

List and describe the different types of neurons.

Answer 19

Motor neurons send messages to a muscle cells. Motor neurons effect some type of change in the body, such as causing a muscle to contract or a gland to release a hormone. Motor neurons receive their information from interneurons.
Interneurons act as bridges between the sensory neurons and the motor neurons. Interneurons are similar in appearance to
motor neurons, but they are much shorter. This is because they are generally located in the brain and spinal cord.
Sensory neurons specialize in receiving information from sensory organs such as our eyes, nose, ears, and skin. They have
the same basic components as motor neurons but are somewhat different in shape. The location of the cell body in sensory neurons is more central and they have fewer dendrites. The sensory neurons send the information they receive to interneurons.
The dendrites of sensory neurons are specialized to detect specific kinds of sensory information. For example, you have sensory neurons on your skin that are specialized to respond to touch, heat, or pressure. Some sensory nerves are wrapped
around the roots of small hairs. These send a signal when the hair is moved. Sensory receptors in the tongue and nose respond
to chemicals. Photoreceptor cells found on the back of the eye respond to changes in light.
All these neurons may be myelinated.

Question 20

Describe the anatomy of the heart

Answer 20

The heart is divided into four chambers. Two of these chambers, the atria, receive blood returning to the heart. The right
atrium receives blood back from the body through a large blood vessel called the vena cava. Blood coming from the head and upper extremities returns through the superior vena cava; blood from the lower extremities returns through the inferior venacava. The left atrium receives blood back from the lungs through the pulmonary veins.
The other two chambers are the ventricles. Blood from the two atria passes through a set of atrioventricular valves into the ventricles. When the heart contracts, the blood is squeezed out of both the ventricles at the same time. Blood exits the right ventricle through the pulmonary artery and travels to the lungs. The left ventricle pumps blood through the aorta and then out to the rest of the body.

Question 21

Describe the effects of Osteoporosis.

Answer 21

The weakening of bones and the fracturing of other bones in the wrist and hand.

Question 22

Describe the basic structure and function of the Cardiovascular system.

Answer 22

The cardiovascular system, consisting of the heart, blood vessels (arteries, veins, and capillaries), and blood, transports oxygen and nutrients to tissues and removes waste products, maintaining homeostasis.

Question 23

Explain the role of active transport in restoring a nerve to its resting place.

Answer 23

Active transport, specifically the sodium-potassium pump, plays a crucial role in restoring a nerve cell to its resting state by actively moving sodium ions out of the cell and potassium ions into it, maintaining the electrochemical gradient essential for nerve signaling.

Question 24

Describe the process by which neurotransmitters transmit a nerve impulse across the synapse.

Answer 24

A nerve impulse triggers the release of neurotransmitters from the presynaptic neuron into the synaptic cleft, where they diffuse and bind to receptors on the postsynaptic neuron, initiating a new impulse or altering its activity.

Question 25

List and describe the different types of neurons.

Answer 25

Sensory neurons that carry information from the body to the central nervous system, motor neurons that transmit signals from the CNS to muscles and glands, and interneurons that connect neurons within the CNS.

Question 26

Explain how the nervous system helps regulate body temperature.

Question 27

Explain the role of active transport in restoring a nerve to its resting place.

Answer 27

Active transport, specifically the sodium-potassium pump, plays a crucial role in restoring a nerve cell to its resting state after an action potential by actively pumping sodium ions out and potassium ions in, re-establishing the ion gradients necessary for the resting potential.

Question 28

Describe the respiratory system and explain how it transports oxygen through the body.

Answer 28

The respiratory system facilitates oxygen intake and carbon dioxide removal. Oxygen enters the body through the nose or mouth, travels through the airways to the lungs, and then diffuses into the bloodstream via tiny air sacs (alveoli) for transport throughout the body.

Question 29

Explain how the blood vessels play a role in regulating blood pressure.

Answer 29

Blood vessels play a crucial role in blood pressure regulation by changing their diameter, which alters resistance to blood flow and thus affects blood pressure.

Question 30

Describe the anatomy of the digestive system.

Answer 30

The digestive system begins at the mouth. There are two types of digestion: mechanical digestion and chemical digestion. In mechanical digestion, food is first chewed by the teeth and then broken down by the tongue, which pushes it to the back of the throat (pharynx). The swallowing reflex takes over and directs the food down into the esophagus, the tube that connects the throat to the stomach. When you swallow, your larynx rises, forcing the epiglottis to cover the opening of the trachea. As a result, food is directed to the esophagus and away from the trachea. When food enters the wrong pipe, it occurs due to mistimed swallowing, causing the epiglottis to misalign. Repeated muscle contractions help move food down the esophagus into the stomach through a process called peristalsis. Once food is fully digested in the stomach, it is gradually released into the small intestine. The small intestine receives the chyme from the stomach. It then transitions into the large intestine. The large intestine consists of the ascending colon, the transverse colon, and the descending colon. Once the large intestine has processed the food through its entirety, it exits the body through the anus.

Question 31

Identify the five different digestive enzymes and the roles they play in chemical digestion.

Answer 31

HAVE TO

Question 32

Explain the process of swallowing.

Answer 32

The act of swallowing is when

Question 33

Describe the the path food takes through the digestive tractd.

Question 34

Provide examples of where mechanical and chemical digestion occurs in the digestive system.

Answer 34

1. Mouth: - Mechanical Digestion: Chewing food with teeth breaks it down into smaller pieces, increasing the surface area for enzymes. - Chemical Digestion: Saliva contains enzymes like amylase, which begins the breakdown of carbohydrates. 2. Stomach: - Mechanical Digestion: The stomach muscles churn the food, mixing it with gastric juices. - Chemical Digestion: Gastric acid (HCl) and enzymes like pepsin start the breakdown of proteins. 3. Small Intestine: - Mechanical Digestion: Segmentation, a rhythmic contraction of the intestinal muscles, mixes food with digestive enzymes. - Chemical Digestion: Pancreatic enzymes (such as lipase, amylase, and proteases) and bile (from the liver) work together to further digest fats, carbohydrates, and proteins. 4. Large Intestine: - Mechanical Digestion: Muscle contractions help move waste through the colon. - Chemical Digestion: Bacteria in the large intestine assist in breaking down any remaining nutrients and fiber. These processes work together to ensure that food is efficiently broken down and the body absorbs nutrients.

Question 35

Explain how the body absorbs nutrients.

Answer 35

The small intestine absorbs most of the nutrients in your food, and your circulatory system passes them on to other parts of your body to store or use. Special cells help absorbed nutrients cross the intestinal lining into your bloodstream.

Question 36

Explain the roles of the three accessory organs in the digestive system.

Answer 36

Liver: The liver plays a vital role in producing bile, which is essential for breaking down fats in the small intestine. It also processes nutrients absorbed from the intestines, detoxifies harmful substances, and stores vitamins and minerals. Additionally, the liver helps regulate blood sugar levels by converting excess glucose into glycogen for storage. 2. Pancreas: The pancreas produces digestive enzymes that are released into the small intestine. These enzymes assist in breaking down carbohydrates, proteins, and fats. The pancreas also produces insulin and glucagon, hormones that regulate blood sugar levels, thus playing a crucial role in metabolic processes. 3. Gallbladder: The gallbladder stores and concentrates bile produced by the liver. When fat enters the small intestine, the gallbladder releases bile into the digestive tract, aiding in the emulsification and absorption of dietary fats.

Question 37

Identify the specific system malfunctions related to diabetes.

Answer 37

Diabetes can cause malfunctions in several systems, including the cardiovascular, kidney, nervous, and eye systems, leading to complications like heart disease, kidney failure, nerve damage, and blindness.

Question 38

Describe the anatomy of the urinary system in the main structure of the kidney.

Answer 38

The urinary system centers around the kidneys, essential organs that filter blood and produce urine. Each kidney contains several vital structures: 1. Renal Cortex: The outer layer with glomeruli, where blood filtration starts, rich in blood vessels and nephrons. 2. Renal Medulla: Beneath the cortex, consisting of renal pyramids that house the loop of Henle and collecting ducts, crucial for urine concentration and water regulation. 3. **Renal Pelvis: The funnel-shaped innermost part that collects urine from collecting ducts and directs it into the ureters, transporting it to the bladder. 4. Calices: Small ducts that channel urine from renal pyramids into the renal pelvis, with minor calyces collecting from individual pyramids and major calyces formed by converging minor calyces. 5. Nephrons: Each kidney has around a million nephrons, consisting of a renal corpuscle (including the glomerulus) and a renal tubule. They filter blood, reabsorb nutrients, and excrete waste. 6. Ureters: Muscular tubes that carry urine from the kidneys to the bladder, although not part of the kidneys themselves. 7. Renal Artery and Vein: The renal arteries supply blood from the abdominal aorta, while the renal veins return deoxygenated blood to the heart. Knowledge of the urinary system's anatomy is vital for understanding fluid balance, waste excretion, and homeostasis.

Question 39

Describe the anatomy of a nephron and explain the process of urine production.

Answer 39

HAVE TO

Question 40

Describe the role the kidneys play in homeostasis.

Answer 40

The kidneys help maintain the proper balance of water and salt, a constant pH, and extracellular fluids.

Question 41

Summarize some disease indicators that can be identified using urinalysis.

Question 42

Describe the anatomy of the male and female reproductive system.

Answer 42

The male reproductive system

Question 43

Explain the context of semen and where each component is produced.

Question 44

Summarize the sex hormones and the rules they play in the reproductive system.

Question 45

I describe how and where fertilization occurs.

Answer 45

Fertilization, where a sperm cell fuses with an egg cell to form a zygote, followed by rapid cell division called cleavage, which results in the formation of a blastula, a ball of cells; then, during gastrulation, the blastula undergoes significant cell movement to establish the three primary germ layers (ectoderm, mesoderm, and endoderm)

Question 46

Explain the initial steps in the three stages of early human development.

Answer 46

Early human development comprises three key stages: the germinal stage, the embryonic stage, and the fetal stage. This process begins with fertilization, an event where a sperm cell successfully penetrates an egg cell, combining genetic material from both parents. This marks the very beginning of a new life. After fertilization, the next step is cell division. As the fertilized egg divides into multiple cells, it travels down the fallopian tube and eventually reaches the uterus, where it will implant itself. This implantation is a critical point, as the developing embryo must securely attach to the uterine lining to ensure a steady supply of nutrients and support necessary for continued growth. Once implantation occurs, the embryo enters the embryonic stage, during which a significant process unfolds: the formation of vital organs and systems. This is when the foundation for the human body is laid. During this stage, the embryo experiences rapid growth and development, beginning to take on a more recognizable shape. As weeks pass, the embryo continues to mature, with organs such as the heart, brain, and lungs starting to develop, setting the stage for the subsequent fetal stage, where growth and refinement of these organs take center stage, preparing the embryo for life outside the womb.

Question 47

Explain how the pH scale works.

Answer 47

The pH scale evaluates the acidity or basicity of a solution, spanning from 0 to 14. A value of 7 represents neutrality, values below 7 indicate acidity, and values above 7 indicate basicity.

Question 48

Explain nerve impulses.

Answer 48

An electrical signal travels along a nerve fiber in response to a stimulus, transmitting a record of sensation from a receptor to an effector. This process involves the propagation of an action potential along the length of a neuron.

Question 49

Name some digestive enzymes.

Answer 49

Amylase (breaks down carbohydrates), lactase (converts lactose into glucose and galactose), sucrase (converts sucrose into glucose and fructose), and maltase (converts maltose into glucose).

Question 50

Explain the first stages of human development.

Answer 50

It begins with fertilization, where a sperm cell fuses with an egg cell to form a zygote. This is followed by rapid cell division called cleavage, which results in the formation of a blastula, a ball of cells. Then, during gastrulation, the blastula undergoes csignificant cell movement to establish the three primary germ layers (ectoderm, mesoderm, and endoderm).

Question 51

Describe the role of bones in maintaining blood calcium levels.

Answer 51

Bones serve as a crucial reservoir of calcium in the human body. When blood calcium levels fall below necessary thresholds, bones release stored calcium into the bloodstream to help maintain proper balance. However, when blood calcium levels are elevated, bones absorb and store excess calcium, ensuring calcium levels remain within a healthy range. This dynamic process highlights bones' important role in regulating calcium homeostasis, which is vital for various bodily functions, including muscle contraction and nerve transmission.

Question 52

Describe the anatomy of a nephron.

Answer 52

The functional unit of the kidneys is composed of a sequence of tubules.

Question 53

Describe the process of urine production.

Answer 53

The kidneys play a vital role in maintaining the body's internal balance by filtering unwanted substances from the blood and producing urine for their excretion. This essential process involves three main steps: glomerular filtration, reabsorption, and secretion. Each stage is crucial in ensuring that the body efficiently eliminates waste. During glomerular filtration, blood is filtered through tiny structures in the kidneys called glomeruli, where waste products and excess water begin to separate. The next step, reabsorption, enables the body to reclaim essential substances such as glucose and certain ions, thereby preventing their loss. Secretion helps to eliminate extra waste materials, ensuring that only waste and excess water are excreted, thereby maintaining homeostasis in the body.

Question 54

List and describe the three kinds of passive transport.

Answer 54

Passive transport refers to the movement that requires no energy input. This process can be understood through the concept of a concentration gradient, where molecules transition from areas of high concentration to areas of low concentration, which is known as moving down their concentration gradient. There are three primary types of passive transport: simple diffusion, facilitated diffusion, and osmosis. Simple diffusion involves the direct movement of small, nonpolar molecules through the plasma membrane. Conversely, larger and more polar molecules need a protected passage through the lipid bilayer; this method, which occurs without energy expenditure, is called facilitated diffusion. Ions and polar substances, such as glucose, use specific protein channels to aid their movement. Osmosis, however, refers to the net movement of water across the plasma membrane. This occurs when the membrane is impermeable to solutes, leading water to migrate toward areas of higher solute concentration in an effort to equalize concentrations on both sides of the membrane.