Praxis (5236) - Biology > 4B2 Organ Structure and Functions > Flashcards

4B2 Organ Structure and Functions Flashcards

Describe the structures and functions of major organ systems: cardiovascular, respiratory, digestive, excretory, immune, musculoskeletal, nervous, endocrine, and reproductive. (171 cards)

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1
Q

What is the primary function of the cardiovascular system?

A

To pump blood throughout the body.

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2
Q

What are the three main parts of the cardiovascular system?

A
  • Heart
  • Blood vessels
  • Blood
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3
Q

What are the two main circuits of the cardiovascular system?

A
  • Pulmonary circuit
  • Systemic circuit

Pulmonary circuit: Moves blood between the heart and the lungs.

Systemic circuit: Moves blood throughout the body.

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4
Q

What are the three layers of muscle tissue in the heart?

A
  • Endocardium
  • Myocardium
  • Pericardium

Endocardium - lines the inside of the heart.

Myocardium - thick muscular layer of the heart.

Pericardium - surrounds the heart.

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5
Q

What are the three main types of blood vessels in the body?

A
  • Arteries
  • Veins
  • Capillaries
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6
Q

What is the major artery that carries oxygenated blood to the body?

A

Aorta

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7
Q

What do coronary arteries supply blood to?

A

They supply oxygenated blood to the heart muscle itself.

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8
Q

What is the function of veins in the cardiovascular system?

A

Carry blood from the body back to the heart.

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9
Q

What type of blood do most veins carry?

A

Deoxygenated blood

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10
Q

What is the major vein that delivers blood from the lower body back to the right atrium of the heart?

A

Inferior vena cava

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11
Q

What are capillaries and where are they located?

A

They are much smaller blood vessels that connect arteries and veins and are located throughout the body’s tissues, where they serve as the site of gas exchange.

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12
Q

What is the main function of arteries in the cardiovascular system?

A

Carry blood throughout the body from the heart.

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13
Q

What are the main components of blood?

A
  • Red blood cells
  • White blood cells
  • Platelets
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14
Q

What are red blood cells designed to carry?

A

Oxygen

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15
Q

What is the role of white blood cells in the body?

A

Cells of the immune system that help prevent infection.

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16
Q

What is the function of platelets in the blood?

A

It help form blood clots to stop bleeding when a blood vessel is injured.

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17
Q

What is the main organ in the cardiovascular system?

A

The heart.

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18
Q

What is the function of the tricuspid valve in the heart?

A

Allows deoxygenated blood to flow from the right atrium to the right ventricle.

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19
Q

What is the function of the mitral valve (bicuspid valve) in the heart?

A

Allows oxygenated blood to flow from the left atrium to the left ventricle.

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20
Q

What is the function of the pulmonary artery?

A

Carries deoxygenated blood to the lungs.

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21
Q

What is the function of the pulmonary vein?

A

Carries oxygenated blood back to the heart from the lungs.

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22
Q

What is the function of the spleen in the cardiovascular system?

A

Filters blood and removes damaged or old red blood cells.

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23
Q

What is the overall function of the respiratory system?

A

The respiratory system:

  • brings air into the body.
  • transfers oxygen into the bloodstream.
  • removes carbon dioxide and wastes from the blood.
  • expels air from the body.
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24
Q

What are the structures that carry out the majority of the function of the pulmonary system by bringing oxygen into the blood?

A

Lungs

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25
What is the **large passageway for air** into and out of the lungs?
Trachea ## Footnote Also known as the windpipe.
26
What are the main passageways from the **trachea to the lungs**?
Bronchi
27
What are the smaller branches that **come off the bronchi and lead to the air sacs**?
Bronchioles
28
What **structures**, commonly called air sacs, serve as the **primary site of gas exchange** in the lungs?
Alveoli
29
What is the opening through which **air, food, and drink enter the body**?
Mouth
30
What is the large, relatively thin muscle that sits at the base of the lungs and functions in inhaling and exhaling?
Diaphragm ## Footnote The diaphragm contracts and flattens during inhalation, increasing thoracic cavity volume and drawing air into the lungs.
31
What are the muscles located between the ribs that **help to move the chest cavity** during inhalation and exhalation?
Intercostal muscles
32
What are some conditions that may interfere with the proper functioning of the **respiratory system**?
* Asthma * Cystic fibrosis * Emphysema * COPD
33
What is the function of **amylase** in the digestive process?
Breaks large polysaccharides into smaller ones.
34
Which enzyme breaks **proteins** down into smaller peptides in the stomach?
Pepsin
35
How do **epithelial cells** of the stomach protect themselves from HCl and pepsin?
Secrete large amounts of **mucus** to form a barrier.
36
What is the function of the **epiglottis** during swallowing?
Directs food down the esophagus. ## Footnote The epiglottis is a flap of tissue that prevents food from entering the trachea and instead directs it down the esophagus during swallowing.
37
Describe the **process** of food moving from the mouth to the stomach.
1. Chewing breaks down food physically. 2. Saliva containing amylase breaks down complex carbohydrates. 3. Food enters the pharynx and then the esophagus. 4. Muscle contractions push food into the stomach.
38
What is the function of the **pyloric sphincter**?
Controls the flow of partially digested food into the small intestine. ## Footnote The pyloric sphincter is a muscular valve that regulates the passage of chyme from the stomach to the small intestine.
39
What happens when a person sees, smells, or anticipates eating food?
The brain sends a signal to the stomach to start **preparing for a meal**. Saliva builds up in the mouth. ## Footnote This signal triggers the stomach to secrete a small amount of hydrochloric acid and activate the smooth muscles in preparation for food intake.
40
What is the role of the **smooth muscles of the stomach** during digestion?
* Churning the stomach at a low rate. * Thoroughly mixing food and gastric juice. ## Footnote The smooth muscles of the stomach churn the food and gastric juice until it is liquefied and ready for release into the small intestine.
41
What happens to the stomach **between meals**?
It is empty and pretty much inactive. ## Footnote It takes about 2-6 hours for the stomach to empty its contents into the small intestine.
42
What is the **lower gastrointestinal tract** composed of?
* most of the small intestine * the large intestine * the anus
43
What is the primary role of the **digestive system**?
To break down food and absorb nutrients.
44
What is the primary role of the **duodenum** in the digestive process?
Chemical digestion of food and preparation for nutrient absorption in the lower GI tract.
45
What is the role of the **liver** in the digestive system?
To release bile salts to help digest fats.
46
What enzyme is responsible for the **breakdown of fats** in the stomach and pancreas?
Lipase
47
Where does **most nutrient absorption** in the lower GI tract occur?
Small intestine
48
What are the **finger-like projections** covering the moist inner lining of the small intestine called?
Villi
49
What is the process responsible for **food and liquid movement** in the gastrointestinal tract?
Peristalsis
50
What is the primary function of the **colon** in the large intestine?
To **absorb water from digested food** and compact waste into feces.
51
What is the role of **good bacteria** in the colon?
* Break down undigested polysaccharides. * Produce gases like nitrogen, carbon dioxide, and methane. * Synthesize vitamins like thiamine, riboflavin, and biotin.
52
What is the function of the **appendix** in the large intestine?
Considered vestigial, may store good bacteria.
53
What is the purpose of the **external and internal sphincter** muscles in the anus?
Control bowel movements.
54
What is the primary role of the **upper gastrointestinal tract**?
Transporting and digesting food.
55
What is the primary function of the **jejunum** in the small intestine?
It absorbs nutrients such as sugars, amino acids, and fatty acids from digested food.
56
What is the primary function of the **ileum** in the small intestine?
Absorbs bile salts and Vitamin B12, and it also secretes digestive enzymes.
57
What is the primary function of the **large intestine**?
Absorbs water and electrolytes, and turns liquid waste into stool.
58
What is the function of the **anus** in the digestive system?
Where stool leaves the body.
59
What is the **difference** between the upper GI and lower GI?
* The **upper GI** consists of the mouth, esophagus, stomach, and the first section of the small intestine (duodenum). * The **lower GI** consists of the rest of the small intestine (jejunum and ileum), the large intestine, and the anus. ## Footnote The upper GI transports and digests food, preparing it for nutrient absorption, while the lower GI aids digestion, absorbs nutrients, and eliminates waste.
60
What is the main function of the **excretory system**?
**Removing wastes** in the body to regulate the body's chemical composition.
61
What are the major functions of the **kidneys**?
* Filter waste products out of the blood. * Help regulate blood composition and pressure.
62
What is a major **byproduct** of human metabolism that the liver converts into urea?
Ammonia
63
How is **urea** eliminated from the body?
Filtered out of the bloodstream by the kidneys and concentrated in the urine.
64
What filters urea?
Glomeruli ## Footnote Clusters of capillaries in nephrons that filter blood to form urine.
65
What is the **basic unit** of the kidney?
Nephron
66
What are the **tubes that carry urine from the kidneys** to the bladder called?
Ureters
67
What **organ** stretches to create a larger holding capacity as it fills with urine?
Bladder
68
What signals the sensation of the need to urinate when the bladder is full?
Nerves of the bladder
69
How do people normally control when they **empty their bladder**?
By controlling a muscular valve at the exit point of the bladder.
70
What is the function of the **liver** in the detoxification process?
Detoxifying and modifying dangerous substances so they can be removed from the body.
71
What happens in the **renal tubules** of the kidneys?
They collect filtrate from the blood, concentrate it into urine, and reabsorb nutrients, water, and sodium chloride.
72
What is the **immune system**?
Includes organs, cells, and tissue that protect the body from infections and diseases. ## Footnote Immune system can fight off bacterial infections, viral infections, parasites, haptens and fungal infections.
73
What are the **organs** of the immune system?
* Tonsils * Thymus * Spleen * Lymph nodes * Bone marrow * Skin
74
What is the role of **thymus** in the immune system?
Produces important immune cells. ## Footnote These immune cells are called T cells.
75
What is the main role of **bone marrow** in the immune system?
The synthesis of red blood cells, white blood cells, and platelets.
76
What are the types of **white blood cells** produced in the bone marrow?
* Neutrophils * Eosinophils * Basophils * Monocytes * Lymphocytes ## Footnote **Neutrophils**: Kill bacteria and fungi. **Eosinophils**: Kill parasites and invade cancerous cells. **Basophils**: Involved in an allergic response. **Monocytes**: Get rid of damaged cells. **Lymphocytes**: Attack viruses and produce antibodies.
77
What is the function of **lymph nodes** in the immune system?
Filter lymph from foreign bodies and produce lymphocytes to attack them.
78
What is the role of **tonsils** in the immune system?
Prevent foreign bodies from entering the lungs.
79
What is the function of the **skin** in the immune system?
Acts as the **first barrier** and defender of the body.
80
What are the **two divisions** of the immune system?
* Innate immunity * Adaptive (specific) immunity
81
What is the primary function of **innate immunity**?
To act as the body's initial line of defense against infections and illnesses. ## Footnote Also known as Non-specific immunity. Examples: * Tears containing lysosomes * Acids in the stomach * Mucus in different body regions * Skin
82
What is the main role of **cytokines** in innate immunity?
Manage the immune cell's reactions.
83
How does the **adaptive immune system** protect the body from re-infection?
By developing immunological memory against diseases and pathogens. ## Footnote After the body is exposed to an antigen, antibodies are created that will recognize the antigen in the future so that a faster immune response can be activated.
84
What are the **two types** of adaptive immunity?
* Humoral immune response * Cell-mediated immune response ## Footnote **Humoral immune response** - produces antigen specific antibodies. **Cell-mediated immune response** - Does not produce antigen specific antibodies.
85
What is the function of **plasma cells** in the immune system?
Produce antibodies that attack foreign antigens.
86
What is the primary role of **T-cells** in the immune system?
Destroy cells directly.
87
What is the primary role of **mast cells**?
They **release histamine** and other chemicals during allergic reactions and inflammation. ## Footnote They help defend against pathogens, but do not “invade.”
88
What is the purpose of **immune tolerance**?
It is the immune system’s ability to **recognize and not attack** the body’s own cells and tissues.
89
What is a **vaccine**?
A substance intended to **stimulate antibody formation** and provide protection against a disease.
90
**How many bones** does an adult human have in its skeletal system?
206
91
What are the **five main categories** of bones in the skeletal system?
* Long bones * Short bones * Flat bones * Sesamoid bones * Irregular bones ## Footnote Bone are classified by their shape.
92
What is the function of **long bones** in the skeletal system?
Long bones **produce blood cells in red marrow** and lengthen through growth at the epiphyseal (growth) plate.
93
Where can **short bones** be found in the body?
Places like the wrists and ankles.
94
Give an example of a **flat bone** in the skeletal system.
* scapula (shoulder blade) * pelvis ## Footnote Flat bones provide a large flat surface for muscle attachment or the protection of organs.
95
What are examples of **irregular bones** in the skeletal system?
* mandible (lower jaw bone) * vertebrae * sacrum
96
What is the function of **sesamoid bones** in the skeletal system?
* Itreduce friction, improve muscle efficiency, and protect tendons. * They are embedded in tendons, often near joints. ## Footnote Example: the patella (kneecap).
97
What type of muscle is found in the **heart**?
Cardiac muscle ## Footnote This muscle contracts involuntarily.
98
What type of muscle is responsible for **peristalsis** in the digestive system?
Visceral muscle
99
What is the function of **skeletal muscles** in the muscular system?
**Facilitate movement** and stimulus response in conjunction with bones of the skeletal system. ## Footnote Skeletal muscle is able to be moved voluntarily.
100
What is the **composition** of skeletal muscle?
* Bundles of myofibrils. * Long and fibrous muscle cells. * Sarcomeres containing actin and myosin fibers.
101
What is the function of **muscle contraction** in movement?
Involves **myosin heads** forming cross-bridges with actin filaments, enabling shortening of muscle fibers and movement.
102
What important functions do muscles perform **besides movement and support**?
* Active in blood circulation. * Generate heat through metabolic processes and muscle contraction.
103
What is the **human musculoskeletal system** composed of?
* bones * skeletal muscles * connective tissue * ligaments * tendons
104
Where do muscles attach **proximally** to bones in the human musculoskeletal system? ## Footnote Proximally = closest point to the body.
At a point called the **origin**.
105
Where do muscles attach **distally** to bones in the human musculoskeletal system? ## Footnote Distally = farthest point from the body.
At the **insertion**, usually crossing a joint in the process.
106
What is the main function of the **skeletal system**?
* support * protection * blood cell manufacture * movement * Assistance in maintaining homeostasis within the body.
107
What is the main function of the **muscular system**?
Facilitates movement, maintains posture, produces heat, and supports circulation through venous return.
108
What is the **neuromuscular junction**?
The point where the motor neuron meets the skeletal muscle, containing a space called a synapse. ## Footnote Signals for muscle contraction are transmitted through acetylcholine at the neuromuscular junction.
109
What happens in a **reflex reaction**?
Instructions bypass the brain for quick, efficient movement in response to stimuli.
110
What is the function of **ligaments** in the musculoskeletal system?
Connect two bones together.
111
What is the function of **tendons** in the musculoskeletal system?
Connect muscles to bones at their origins and insertions.
112
How do muscles **work in teams**?
For every muscle that flexes, there is an opposing muscle that must lengthen or flex.
113
What is the role of **bones** in muscle movement?
Provide the **framework** for skeletal muscle attachment.
114
What is the purpose of **joints** in the musculoskeletal system?
Allow for movement of the joints by connecting involved muscles to both bones at their origin and insertion.
115
What is the significance of the **musculoskeletal system** in the human body?
* Moves the body. * Responds to stimuli. * Offers support and protection to vital organs. * Participates in circulation.
116
What is the **nervous system**?
The collection of cells, tissues, and organs in the body that facilitate electrochemical communication throughout the body.
117
What are the **three main organs** of the nervous system?
* Brain * Spinal cord * Nerves
118
What are **neurons**?
Specialized cells that can send electrochemical signals.
119
What are the **two main parts** of the nervous system?
* Central nervous system * Peripheral nervous system
120
What does the **central nervous system** include?
* Brain * Spinal cord
121
What are the **three main parts** of the **brain**?
* Cerebrum * Cerebellum * Brainstem
122
What is the **cerebrum** responsible for?
Main processing organ of the body.
123
What is the **cerebellum** involved in?
Fine motor coordination, motor learning, and more.
124
What is the **brainstem** responsible for?
Involuntary body processes such as breathing, heart rate, and sleep regulation.
125
What is the **spinal cord's** function?
Carries information from the body to the brain and from the brain to the body.
126
What can happen when there is damage to the **spinal cord**?
Issues with perceiving sensations and controlling motor function in the body.
127
What are some examples of diseases that can affect the **central nervous system**?
* Alzheimer's disease * Multiple sclerosis * Epilepsy * Cancer * Traumatic brain injury * Prion disease
128
What is the **peripheral nervous system**?
All of the nerves in the body outside of the central nervous system.
129
What are the **two parts** of the efferent nervous system?
* Somatic nervous system * Autonomic nervous system
130
What does the **somatic nervous system** control?
Processes that are under a person's **conscious control**.
131
What does the **autonomic nervous system** control?
Processes that are **not under a person's conscious control**.
132
What are the **two divisions** of the autonomic nervous system?
* Sympathetic nervous system * Parasympathetic nervous system
133
What does the **sympathetic nervous system** control?
**"Fight or flight"** response and is activated during times of stress.
134
What does the **parasympathetic nervous system** control?
**"Rest and digest"** part of the nervous system.
135
What is the body's response to being **presented with a threat**?
* Dilation of pupils. * Increase in heart rate. * Increase in breathing.
136
What is the function of the **afferent division** of the peripheral nervous system?
Sends sensory information **from the body to the brain**.
137
What is the function of the **efferent division** of the peripheral nervous system?
Sends motor information **from the brain to the glands and muscles**.
138
What is the **endocrine system**?
A network consisting of glands that produce and secrete hormones internally.
139
What is the main **function** of the endocrine system?
To regulate and monitor the levels of hormones circulating in the blood. ## Footnote Endocrine system plays a large role in homeostasis.
140
What are **hormones**?
Chemicals that travel to organs, skin, other tissues, and muscles in the body. ## Footnote Processes affected by hormones include: * Metabolism * Sleep * Sexual development and function * Blood pressure * Temperature * Development and growth
141
What are the **major glands** that make up the endocrine system?
* Hypothalamus * Pituitary * Thyroid * Parathyroid * Thymus * Adrenal * Pancreas
142
What is the role of the **hypothalamus** in the endocrine system?
Regulating and controlling the endocrine system by combining information from the nervous system and other glands.
143
What is the function of the **pituitary gland**?
To produce hormones that control other glands and bodily functions like blood pressure and water balance.
144
Where is the **thyroid gland** located and what is its primary responsibility?
Located at the front of the neck, responsible for metabolism by producing the thyroid hormone.
145
What is the role of the **pancreas** in the endocrine system?
**Produces insulin**, an important hormone that regulates the level of sugar in the blood.
146
How do hormones **travel** to their target organ or cell?
Through the blood, where they attach and bind to specific receptors on the target cell.
147
What is the key function of the **parathyroid gland** in the endocrine system?
Regulation of calcium in the blood.
148
What is the key function of the **adrenal gland** in the endocrine system?
Essential for the body's fight-or-flight response by releasing adrenaline.
149
How does the endocrine system achieve **metabolic balance** in the body?
* By regulating the body's cellular metabolism. * By balancing the levels of sugar and other nutrients. * By regulating blood pressure and heart rate. * By influencing sleep patterns. * By controlling digestion.
150
What is the **reproductive system**?
The system responsible for the **creation of offspring** from gametes in sexually reproducing organisms.
151
What is a **gamete**?
A cell that contains one set of genetic material. ## Footnote Example: Egg and Sperm.
152
What is the function of the **female reproductive system**?
To produce eggs via the menstrual cycle.
153
What organs are involved in the **female reproductive system**?
* Uterus * Ovaries * Vagina * Breasts
154
What is the function of the **uterus**?
Houses a developing fetus until birth.
155
What is the function of the **ovaries**?
To house premature eggs and release mature eggs during each menstrual cycle.
156
What is the function of the **vagina**?
To connect the female reproductive system to the external environment and serve as the birth canal.
157
What is the function of the **breasts** in the female reproductive system?
To produce milk for infants.
158
What are the **four phases** of the menstrual cycle?
1. Menses phase 2. Follicular phase 3. Ovulation 4. Luteal phase
159
What happens during the **menses phase** of the menstrual cycle?
Old uterine tissue is shed from the body, resulting in bleeding.
160
What occurs during the **follicular phase**?
Ovaries are stimulated to produce follicles that contain eggs.
161
What **hormone** leads to the thickening of uterine tissue during the follicular phase?
**Estrogen**, stimulated by follicle-stimulating hormone. | (FSH)
162
When does **ovulation typically occur** in the menstrual cycle?
Around day 14. ## Footnote At this time an egg is released for potential fertilization.
163
What hormone **triggers the release of an egg** during ovulation?
Luteinizing hormone.
164
What is the **final phase** of the menstrual cycle?
Luteal phase ## Footnote The egg is released from the follicle and travels through the fallopian tube, where it may be fertilized before reaching the uterus.
165
What are the **three layers** of the uterus?
* Endometrium * Myometrium * Serosa
166
What are some **common conditions** that can affect the female reproductive system?
* Polycystic ovarian syndrome (PCOS) * Uterine fibroids * Endometriosis
167
What is the function of the **male reproductive system**?
To produce sperm.
168
What are the **major structures** of the male reproductive system?
* Penis * Testes
169
Where are **sperm produced** in the male reproductive system?
**Seminiferous tubules** of the testes.
170
What is the external structure that **carries sperm out** of the male body during ejaculation?
Urethra ## Footnote It runs through the penis and serves as the final passageway for sperm to exit the body.
171
What **structures** are housed in the scrotum in males?
Testes
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