Quiz #5- Senses and Endocrine system

Question 1

what is The somatosensory system

Answer 1

The somatosensory system is responsible for our sense of touch, pressure, temperature, and body position.

Question 2

what does the somatosensory system consist of

Answer 2

It includes receptors in the skin, muscles, joints, and other tissues that detect various stimuli and send signals to the brain.

Question 3

what are the nerve endings in somatosensory system

Answer 3

It includes free nerve endings that detect pain, temperature, and some touch sensations, as well as encapsulated nerve endings that detect pressure, vibration, and other touch sensations.

Question 4

different types of receptors in the somatosensory system

Answer 4

There are different types of receptors, like

mechanoreceptors that detect mechanical stimuli,

thermoreceptors that detect temperature changes, and

nociceptors that detect painful stimuli.

Question 5

Mechanoreceptors

Answer 5

Mechanoreceptors are sensory receptors that detect mechanical stimuli, such as touch, pressure, vibration, and movement. They are found in the skin, muscles, joints, and other tissues throughout the body.

Question 6

different types of mechanoreceptors

Answer 6

Meissner’s corpuscles - Detect light touch and flutter

Pacinian corpuscles - Detect deep pressure and vibration

Ruffini endings - Detect skin stretch and joint position

Merkel’s discs - Detect sustained pressure and texture

Question 7

Meissner’s corpuscles

Answer 7

• Detect light touch and flutter

Question 8

Pacinian corpuscles

Answer 8

Detect deep pressure and vibration

Question 9

Ruffini endings

Answer 9

Ruffini endings - Detect skin stretch and joint position

Question 10

Merkel’s discs

Answer 10

Detect sustained pressure and texture

Question 11

example of somatosensory system

Answer 11

For example, when you lightly touch a smooth surface, the Meissner’s corpuscles in your fingertips detect the gentle pressure and send signals to your brain, allowing you to perceive the softness of the material. Pretty cool, right?

Question 12

Thermoreceptors

Answer 12

Thermoreceptors are a type of sensory receptor that detect changes in temperature. They are found in the skin and other tissues throughout the body.

Question 13

two main types of Thermoreceptors

Answer 13

Cold receptors - These are larger, myelinated nerve fibers that are located in the upper layers of the skin. They respond to decreases in temperature and send signals to the brain that we interpret as a “cold” sensation.

Warm receptors - These are smaller, unmyelinated nerve fibers that are located deeper in the dermis layer of the skin. They respond to increases in temperature and send signals that we perceive as “warmth.”

Question 14

how do thermoreceptors work?

Answer 14

The thermoreceptors work by converting the thermal energy (heat or cold) into electrical signals that travel along the somatosensory pathways to the brain. In the brain, these signals are processed and interpreted, allowing us to feel and distinguish between hot, cold, and neutral temperatures.

Question 15

Cold receptors

Answer 15

These are larger, myelinated nerve fibers that are located in the upper layers of the skin. They respond to decreases in temperature and send signals to the brain that we interpret as a “cold” sensation.

Question 16

Warm receptors

Answer 16

These are smaller, unmyelinated nerve fibers that are located deeper in the dermis layer of the skin. They respond to increases in temperature and send signals that we perceive as “warmth.”

Question 17

main types of proprioceptors:

Answer 17

Muscle spindles - Located within the muscle fibers, these detect changes in muscle length and tension, allowing us to sense the position and movement of our limbs.

Golgi tendon organs - Found at the junction of muscles and tendons, these detect changes in muscle force and tension, providing information about the amount of effort being exerted.

Joint receptors - Located in the joint capsules and ligaments, these detect the position and movement of our joints.

Question 18

Muscle spindles

Answer 18

Located within the muscle fibers, these detect changes in muscle length and tension, allowing us to sense the position and movement of our limbs

Question 19

Golgi tendon organs

Answer 19

Found at the junction of muscles and tendons, these detect changes in muscle force and tension, providing information about the amount of effort being exerted.

Question 20

Proprioceptors

Answer 20

Proprioceptors are sensory receptors that detect the position and movement of our body parts. They are found in our muscles, tendons, joints, and other tissues.

Question 21

Joint receptors

Answer 21

Joint receptors - Located in the joint capsules and ligaments, these detect the position and movement of our joints.

Question 22

how do proprioceptors work?

Answer 22

These proprioceptors convert mechanical stimuli, like muscle stretch or joint rotation, into electrical signals that travel through the somatosensory pathways to the brain. In the brain, these signals are processed and integrated, allowing us to have a constant awareness of our body’s position and movements.

Question 23

main types of nociceptors:

Answer 23

Mechanical nociceptors - These detect intense mechanical forces, like a sharp object piercing the skin.

Thermal nociceptors - These detect extreme temperatures, both hot and cold, that could potentially damage tissue.

These can respond to multiple types of stimuli, including mechanical, thermal, and chemical.

Question 24

Nociceptors

Answer 24

Nociceptors are a type of sensory receptor that respond to potentially damaging or painful stimuli. They are found in the skin, muscles, joints, and internal organs throughout the body.

Question 25

Mechanical nociceptors

Answer 25

These detect intense mechanical forces, like a sharp object piercing the skin.

Question 26

Thermal nociceptors

Answer 26

These detect extreme temperatures, both hot and cold, that could potentially damage tissue.

Question 27

Polymodal nociceptors

Answer 27

These can respond to multiple types of stimuli, including mechanical, thermal, and chemical.

Question 27

how do nociceptors work?

Answer 27

When these nociceptors are activated by a harmful or potentially harmful stimulus, they generate electrical signals that travel through the somatosensory pathways to the spinal cord and brain. In the brain, these signals are interpreted as the sensation of pain.

Question 28

Baroreceptors

Answer 28

Baroreceptors are a type of mechanoreceptor that detect changes in blood pressure and blood volume. They are found in the walls of blood vessels, particularly in the carotid arteries and aorta.

Question 29

signals and triggers a response to help regulate blood pressure.

Answer 29

Decreasing the activity of the sympathetic nervous system, which lowers heart rate and blood vessel constriction

Increasing the activity of the parasympathetic nervous system, which further slows the heart rate

Stimulating the kidneys to excrete more water and sodium, reducing blood volume

Question 30

what does the baroreceptor reflex help with

Answer 30

This baroreceptor reflex helps maintain a stable blood pressure and prevent dangerous spikes or drops in blood pressure.

Question 31

Photoreceptors

Answer 31

Photoreceptors are specialized sensory cells found in the retina of the eye. They are responsible for converting light energy into electrical signals that the brain can interpret as vision.

Question 32

two main types of photoreceptors:

Answer 32

Rods - These are more numerous and highly sensitive to light, allowing us to see in low-light conditions. Rods are responsible for our black-and-white, peripheral vision.

Cones - These are less numerous but more specialized for color vision. There are three types of cones, each sensitive to different wavelengths of light (red, green, or blue). Cones allow us to perceive a wide range of colors.

Question 33

Rods

Answer 33

These are more numerous and highly sensitive to light, allowing us to see in low-light conditions. Rods are responsible for our black-and-white, peripheral vision.

Question 34

Cones

Answer 34

These are less numerous but more specialized for color vision. There are three types of cones, each sensitive to different wavelengths of light (red, green, or blue). Cones allow us to perceive a wide range of colors.

Question 35

how do photoreceptors work?

Answer 35

When light enters the eye and reaches the retina, it strikes the photoreceptors. This causes changes in the photoreceptor cells, generating electrical signals that are then transmitted through the optic nerve to the brain.

Question 36

perception

Answer 36

Perception is the conscious awareness and interpretation of the sensations we experience through our senses. It’s not just about detecting the stimulus, but about how our brain organizes and gives meaning to that information.

Question 37

process of perception

Answer 37

Sensation - Our sensory receptors (like photoreceptors, mechanoreceptors, etc.) detect various stimuli in the environment and convert them into electrical signals.

Transduction - These electrical signals are then transmitted through the nervous system to the brain.

Organization - In the brain, the signals are organized and integrated with our past experiences and knowledge.

Interpretation - Finally, the brain interprets the organized sensory information, allowing us to consciously perceive and make sense of the world around us.

Question 38

Adaptation

Answer 38

is a decrease in the sensitivity of a sensory receptor to a constant or repeated stimulus. This allows our senses to adjust and prevent us from being overwhelmed by unchanging sensations.

Question 39

different types of adaption

Answer 39

Sensory adaptation - This is when a sensory receptor, like a photoreceptor or mechanoreceptor, becomes less responsive to a constant stimulus over time. For example, you stop noticing the feeling of your clothes on your skin after a while.

Neural adaptation - This is when the neurons in the sensory pathways become less responsive to a repeated stimulus. This helps prevent sensory overload in the brain.

Perceptual adaptation - This is when our brain adjusts its interpretation of a sensory input over time. For example, when you get a new pair of glasses, it takes a little while for your brain to adapt to the new visual input.

Question 40

Projection

Answer 40

Projection is the process by which our brain determines the location of a sensory stimulus in the external world. It allows us to know where a sensation is originating from, even if we can’t see the source directly.

Question 41

projection examples

Answer 41

Touch - When you touch something, the somatosensory receptors in your skin send signals to your brain. Your brain can then project the sensation to the exact location on your body where the touch occurred.

Hearing - The way sound waves reach your two ears at slightly different times and volumes allows your brain to project the location of the sound source in space.

Vision - The inverted image that is focused on your retina is “flipped” by your brain, allowing you to perceive the world in its proper orientation.

Question 42

Referred pain

Answer 42

Referred pain occurs when we feel pain in an area of the body that is not the actual site of the injury or problem. This happens because of the way our sensory nerves are organized and connected in the body.

Question 43

how does referred pain work

Answer 43

Certain internal organs, like the heart or gallbladder, share nerve connections with the skin and muscles of the body wall.

When there is a problem with an internal organ, the pain signals can get “referred” or projected to the related area of the body wall.

For example, pain from a heart attack is often felt in the left arm or shoulder, even though the heart is the source of the problem.

Question 44

why referred pain happens

Answer 44

This happens because the brain has difficulty precisely localizing the origin of the pain signals when they are coming from internal organs. Instead, the brain interprets the pain as coming from the area of the body wall that shares the same nerve connections.

Question 44

Cornea

Answer 44

Cornea - The clear, curved front part of the eye that refracts (bends) light as it enters the eye.

Question 45

Pupil

Answer 45

The opening in the center of the iris that controls the amount of light entering the eye.

Question 46

Iris

Answer 46

The colored part of the eye that contains muscles that dilate and constrict the pupil.

Question 47

Lens

Answer 47

The transparent, flexible structure behind the iris that further focuses light onto the retina.

Question 48

Retina

Answer 48

Retina - The light-sensitive layer at the back of the eye that contains photoreceptors (rods and cones) to convert light into electrical signals.

Question 49

Optic Nerve

Answer 49

Transmits the electrical signals from the retina to the brain, where they are interpreted as vision.

Question 49

Sclera

Answer 49

The white, protective outer layer of the eye

Question 50

Vitreous Humor

Answer 50

The clear, jelly-like substance that fills the space between the lens and the retina, helping to maintain the shape of the eye.

Question 51

Choroid

Answer 51

The layer between the sclera and retina that provides blood supply to the eye.

Question 52

Eyelids

Answer 52

These protect the eye and help distribute tears across the surface of the eye.

Question 53

Eyelashes

Answer 53

These act as a first line of defense, trapping dust and debris before it can enter the eye.

Question 54

Eyebrows -

Answer 54

These help shield the eyes from sweat and direct light.

Question 55

Lacrimal System

Answer 55

This includes the tear glands, tear ducts, and tear drainage system. It produces, distributes, and drains the tears that lubricate and protect the eye.

Question 56

Extrinsic Eye Muscles -

Answer 56

These six muscles (superior, inferior, lateral, and medial rectus; superior and inferior oblique) control the movement and positioning of the eyeball.

Question 57

Conjunctiva

Answer 57

This is the thin, transparent membrane that lines the inner eyelids and covers the front of the sclera.

Question 58

the pathway for light as it enters the eye and reaches the optic nerve

Answer 58

1. Cornea - Light waves first enter the eye through the clear, curved cornea. The cornea refracts (bends) the light, helping to focus it.
2. Pupil - The light then passes through the pupil, the opening in the center of the iris. The size of the pupil can change to control the amount of light entering the eye.
3. Lens - Next, the light travels through the flexible lens, which further focuses the light rays.
4. Vitreous Humor - The light then passes through the vitreous humor, the clear, jelly-like substance that fills the space between the lens and the retina.
5. Retina - The focused light finally reaches the retina, the light-sensitive layer at the back of the eye. The retina contains photoreceptor cells (rods and cones) that convert the light energy into electrical signals.
6. Optic Nerve - These electrical signals are then transmitted through the optic nerve to the brain, where they are interpreted as visual images.

Question 59

cranial nerve associated with vision

Answer 59

Optic Nerve (Cranial Nerve II) - Transmits visual information from the retina to the brain.

Question 60

cranial nerve associated with hearing and equilibrium

Answer 60

Vestibulocochlear Nerve (Cranial Nerve VIII) - Carries sensory information from the inner ear, including the cochlea (hearing) and vestibular apparatus (balance and equilibrium).

Question 61

cranial nerve associated with Gustatory (Taste) Pathway:

Answer 61

Facial Nerve (Cranial Nerve VII) - Innervates taste buds on the anterior two-thirds of the tongue.

Glossopharyngeal Nerve (Cranial Nerve IX) - Innervates taste buds on the posterior one-third of the tongue.

Vagus Nerve (Cranial Nerve X) - Innervates taste buds on the palate, pharynx, and epiglottis.

Question 62

parts of the outer ear

Answer 62

Auricle (Pinna) - The visible, outer part of the ear that collects sound waves and channels them into the ear canal.

External Auditory Canal - The tube-like structure that directs the sound waves toward the eardrum.

Tympanic Membrane (Eardrum) - Vibrates when sound waves strike it, transmitting the vibrations to the middle ear.

Question 63

Auricle (Pinna)

Answer 63

The visible, outer part of the ear that collects sound waves and channels them into the ear canal. (part of the outer ear)

Question 64

External Auditory Canal

Answer 64

The tube-like structure that directs the sound waves toward the eardrum.
(part of the outer ear)

Question 65

Tympanic Membrane (Eardrum)

Answer 65

Vibrates when sound waves strike it, transmitting the vibrations to the middle ear. (part of pouter ear)

Question 66

parts of the middle ear

Answer 66

Auditory Ossicles - The three tiny bones (malleus, incus, and stapes) that transmit the vibrations from the eardrum to the oval window of the inner ear.

Eustachian Tube - Connects the middle ear to the back of the throat, allowing air pressure to be equalized on both sides of the eardrum.

Question 67

Eustachian Tube

Answer 67

Connects the middle ear to the back of the throat, allowing air pressure to be equalized on both sides of the eardrum. (part of the middle ear)

Question 68

Eustachian Tube

Answer 68

Connects the middle ear to the back of the throat, allowing air pressure to be equalized on both sides of the eardrum.

Question 69

parts of the inner ear

Answer 69

Cochlea - Contains the organ of Corti, which has hair cells that convert the vibrations into electrical signals for the brain to interpret as sound.

Vestibular System - Includes the utricle, saccule, and semicircular canals, which detect head and body movements and help maintain balance and equilibrium.

Vestibulocochlear Nerve (Cranial Nerve VIII) - Transmits the electrical signals from the inner ear to the brain.

Question 70

pathway for sound vibrations including all relevant structures

Answer 70

1. Auricle (Pinna) - Sound waves are collected and funneled into the external auditory canal by the outer ear.
2. External Auditory Canal - The sound waves travel through the canal and strike the tympanic membrane (eardrum).
3. Tympanic Membrane - The vibrations of the eardrum are then transmitted to the auditory ossicles (malleus, incus, and stapes) in the middle ear.
4. Auditory Ossicles - The vibrations of the ossicles are amplified and passed on to the oval window, which is the entrance to the inner ear.
5. Oval Window - The vibrations of the oval window create pressure waves in the fluid-filled cochlea of the inner ear.
6. Cochlea - Inside the cochlea, the pressure waves bend the hair cells of the organ of Corti, which converts the mechanical vibrations into electrical signals.
7. Vestibulocochlear Nerve (Cranial Nerve VIII) - These electrical signals are then transmitted through the vestibulocochlear nerve to the brain, where they are interpreted as sound.

Question 70

Vestibulocochlear Nerve (Cranial Nerve VIII)

Answer 70

Transmits the electrical signals from the inner ear to the brain. (part of the inner ear)

Question 70

Cochlea

Answer 70

Contains the organ of Corti, which has hair cells that convert the vibrations into electrical signals for the brain to interpret as sound.
(part of inner ear)

Question 71

Static Equilibrium:

Answer 71

Static equilibrium is the sense of body orientation relative to the pull of gravity when the head and body are still.

The receptors for static equilibrium are located in the utricle and saccule of the inner ear.

These receptors contain hair cells that are stimulated by the movement of otoliths (calcium carbonate crystals) in response to gravity.

This allows us to sense the position of our head and body when we are not moving.

Question 71

Vestibular System

Answer 71

Includes the utricle, saccule, and semicircular canals, which detect head and body movements and help maintain balance and equilibrium. (part of inner ear)

Question 72

Dynamic equilibrium

Answer 72

Dynamic equilibrium is the sense of balance and movement in response to rotational acceleration and deceleration.

The receptors for dynamic equilibrium are located in the semicircular canals of the inner ear.

The semicircular canals contain hair cells that are stimulated by the movement of fluid within the canals as the head rotates.

This allows us to detect and respond to changes in the position and movement of our head and body.

Question 72

difference between dynamic and static equilibrium

Answer 72

Static equilibrium uses the utricle and saccule to detect orientation relative to gravity.

Dynamic equilibrium uses the semicircular canals to detect rotational movements and changes in acceleration.

Question 73

The Gustatory Pathway:

Answer 73

Taste receptors in the taste buds on the tongue, palate, pharynx, and epiglottis detect taste stimuli.

These receptors send signals through the facial (VII), glossopharyngeal (IX), and vagus (X) cranial nerves.

The signals travel to the medulla oblongata, then the thalamus, and finally reach the primary gustatory area in the parietal lobe of the cerebral cortex.

Question 74

The 5 Primary Tastes:

Answer 74

Sour

Sweet

Bitter

Salty

Umami (savory/meaty)

Question 75

Location of Taste Buds:

Answer 75

The majority of taste buds are located on the tongue, especially on the vallate and fungiform papillae.

There are also some taste buds on the roof of the mouth, the pharynx, and the epiglottis.

Question 76

Emotional Response to Food:

Answer 76

Emotional and behavioral responses to taste/food involve the limbic system.

areas of the brain associate taste and food with memories, emotions, and motivations, influencing our likes, dislikes, and cravings.

Question 76

parts of the brain responsible for conscious awareness of taste

Answer 76

Conscious taste perception occurs in the primary gustatory area of the parietal lobe.

Question 77

Appetite and Hunger Regulation:

Answer 77

Appetite and hunger regulation is primarily controlled by the hypothalamus.

Question 78

Lipid-Soluble Hormones:

Answer 78

Lipid -soluble hormones, like steroid hormones and thyroid hormones, are able to easily pass through the cell membrane.

Once inside the target cell, the hormone binds to a specific receptor protein in the cytoplasm or nucleus.

This hormone-receptor complex then binds to specific DNA sequences, called hormone response elements, and alters gene expression.

This changes the activity of the target cell by affecting the synthesis of specific proteins.

Question 79

examples of lipid soluble hormones

Answer 79

Examples include estrogen, testosterone, and thyroid hormones (T3 and T4).

Question 80

Water-Soluble Hormones:

Answer 80

Water-soluble hormones, like peptide hormones and modified amino acid hormones, cannot easily pass through the cell membrane.

Instead, they bind to receptors on the target cell’s surface, activating a second messenger system inside the cell.

This second messenger, like cyclic AMP (cAMP), then triggers a cascade of intracellular reactions that alter the cell’s activities.

Water-soluble hormones have a more rapid, short-term effect compared to lipid-soluble hormones.

Question 81

examples of water-soluble hormones

Answer 81

Examples include insulin, growth hormone, and antidiuretic hormone (ADH).

Question 82

key difference between lipid soluble and water soluble hormones

Answer 82

The key difference is that lipid-soluble hormones can directly enter the target cell and affect gene expression, while water-soluble hormones work through cell surface receptors and second messenger systems. Both mechanisms allow hormones to elicit specific responses in their target cell

Question 83

the difference between positive and negative feedback

Answer 83

negative feedback keeps things stable, while positive feedback allows certain processes to rapidly escalate

negative are more common

Question 84

Endocrine System Responses:

Answer 84

Uses chemical messengers called hormones released into the bloodstream

Effects are widespread and longer-term, acting over seconds to days

Hormones can target cells throughout the body, even distant from the gland

Question 85

Nervous System Responses:

Answer 85

Uses electrical impulses (neurotransmitters) to rapidly transmit signals

Effects are localized and short-term, acting within milliseconds

Targets specific muscle, gland, or other cells near the site of release

Question 86

key differences between nervous and endocrine responses

Answer 86

The nervous system is faster and more precise, while the endocrine system is slower but has broader, more global effects.

Nervous system signals are electrical, while endocrine system signals are chemical.

Nervous system acts locally, endocrine system acts systemically.

Question 87

the brain structure that controls the pituitary gland

Answer 87

the hypothalamus monitors various conditions in the body and sends signals to the pituitary gland to secrete the appropriate hormones in response. This allows the endocrine system to maintain homeostasis and regulate important bodily functions.

Question 88

hGh

Answer 88

Human growth hormone

Source: The anterior pituitary gland

Target Cells: Liver, muscle, bone, and other tissues

Functions:
Stimulates the liver to synthesize and secrete insulin-like growth factors (IGFs)

IGFs then promote growth and reproduction of body cells

Increases protein synthesis

Enhances tissue repair

Speeds up the breakdown of triglycerides and increases blood glucose levels

Question 89

PRL

Answer 89

Name: Prolactin (PRL)

Source: Anterior pituitary gland

Target Cells: Mammary glands

Functions:
Initiates and maintains milk production (lactation) in the mammary glands following childbirth

Helps prepare the mammary glands for milk production during pregnancy

Its effects in males are less well understood, but it may play a role in sexual function

Question 90

TSH

Answer 90

Name: Thyroid-Stimulating Hormone (TSH)

Source: Anterior pituitary gland

Target Cells: Thyroid gland

Functions:
Stimulates the thyroid gland to synthesize and secrete the thyroid hormones thyroxine (T4) and triiodothyronine (T3)

Helps regulate metabolism, growth, and development in the body

Secretion of TSH is controlled by thyroid-releasing hormone (TRH) from the hypothalamus

As blood levels of T3 and T4 increase, secretion of TSH decreases (negative feedback)

Question 91

FSH

Answer 91

Name: Follicle-Stimulating Hormone (FSH)

Source: Anterior pituitary gland

Target Cells:

In females: Ovaries

In males: Testes

Functions:

In females, FSH initiates the development of ovarian follicles and stimulates the secretion of estrogens by the ovaries

In males, FSH stimulates the testes to produce sperm

FSH, along with luteinizing hormone (LH), are known as the “gonadotropins” as they affect the male and female gonads (testes and ovaries)

Question 92

LH

Answer 92

Name: Luteinizing Hormone (LH)

Source: Anterior pituitary gland

Target Cells:
In females: Ovaries
In males: Testes

Functions:
In females, LH stimulates the secretion of estrogens and progesterone, triggers ovulation, and helps form the corpus luteum

In males, LH stimulates the testes to produce testosterone

Along with FSH, LH is one of the two “gonadotropins” that regulate the function of the male and female gonads (testes and ovaries).

Question 93

ACTH

Answer 93

Name: Adrenocorticotropic Hormone (ACTH)

Source: Anterior pituitary gland

Target Cells: Adrenal cortex

Functions:

Stimulates the adrenal cortex to secrete glucocorticoids, primarily cortisol

Cortisol helps regulate metabolism, immune function, and the body’s stress response

ACTH secretion is increased in response to stress, which then leads to increased cortisol production

Question 94

MSH

Answer 94

Name: Melanocyte-Stimulating Hormone (MSH)

Source: Anterior pituitary gland

Target Cells: Melanocytes (pigment-producing cells)

Functions:

The exact role of MSH in humans is not fully understood

It may influence brain activity and mood

When present in excess, MSH can cause darkening of the skin (hyperpigmentation)

Question 95

Oxytocin

Answer 95

Source: Hypothalamus (produced) and Posterior Pituitary (stored and released)

Target Cells:

Uterus

Mammary glands

Functions:

Stimulates contraction of the smooth muscle cells in the uterus during childbirth, helping to facilitate labor and delivery

Stimulates the milk ejection reflex, causing the release of milk from the mammary glands during breastfeeding

Plays a role in social bonding and trust

Question 96

ADH

Answer 96

Name: Antidiuretic Hormone (ADH) or Vasopressin

Source: Hypothalamus (produced) and Posterior Pituitary (stored and released)

Target Cells: Kidneys

Functions:
Increases water reabsorption by the kidneys, leading to decreased urine output

Helps maintain proper fluid balance and blood pressure in the body

Secretion of ADH is controlled by the hypothalamus based on factors like blood osmolarity and blood volume

Question 97

T4/T3

Answer 97

Names:
Thyroxine (T4)
Triiodothyronine (T3)

Source: Thyroid gland

Target Cells: Most cells in the body

Functions:

Regulate metabolism, growth, and development

Increase the rate at which cells release energy from carbohydrates and fats

Enhance protein synthesis

Stimulate the breakdown and mobilization of lipids

T4 and T3 are the two main hormones produced by the thyroid gland. T4 is the more abundant form, while T3 is the more potent and active form.

Question 97

PTH

Answer 97

Name: Parathyroid Hormone (PTH)

Source: Parathyroid glands

Target Cells: Bone, kidneys, intestines

Functions:

Increases blood calcium levels

Stimulates bone resorption, releasing calcium from bone into the bloodstream

Increases calcium reabsorption in the kidneys, preventing its excretion

Increases calcium absorption from the intestines

PTH is the main regulator of blood calcium levels in the body. It works to counteract decreases in blood calcium by mobilizing calcium from the bones, kidneys, and intestines.

PTH secretion is controlled by a negative feedback loop involving blood calcium concentrations. When calcium levels drop, PTH is released to restore normal levels.

Question 97

calcitonin

Answer 97

Name: Calcitonin

Source: Parafollicular (C) cells of the thyroid gland

Target Cells: Bone, kidneys, intestines

Functions:
Helps lower blood calcium levels

Stimulates the storage of calcium in bones

Increases the rate of calcium excretion in the urine

Opposes the effects of parathyroid hormone (PTH), which increases blood calcium

Question 98

glucagon

Answer 98

Name: Glucagon

Source: Alpha cells of the pancreatic islets

Target Cells: Liver

Functions:

Increases blood glucose levels

Stimulates the liver to break down glycogen into glucose (glycogenolysis)

Stimulates the liver to convert non-carbohydrates (like amino acids and fats) into glucose (gluconeogenesis)

Glucagon is the counterpart to insulin, which decreases blood glucose levels. Together, insulin and glucagon work to maintain a relatively stable blood glucose concentration.

The release of glucagon is controlled by a negative feedback mechanism involving low blood glucose levels (hypoglycemia). When blood glucose drops, glucagon is secreted to raise it back up.

Question 99

insulin

Answer 99

Name: Insulin

Source: Beta cells of the pancreatic islets

Target Cells: Most cells in the body

Functions:

Decreases blood glucose levels

Stimulates the transport of glucose into cells, especially muscle and adipose (fat) cells

Promotes the storage of glucose as glycogen in the liver and muscles

Enhances protein synthesis

Stimulates the storage of fat in adipose tissue

Insulin is the counterpart to glucagon, working to lower blood glucose levels. Together, insulin and glucagon maintain a relatively stable blood glucose concentration.

The release of insulin is controlled by a negative feedback mechanism involving high blood glucose levels (hyperglycemia). When blood glucose rises, insulin is secreted to bring it back down.

Question 100

aldosterone

Answer 100

Name: Aldosterone

Source: Adrenal cortex (zona glomerulosa)

Target Cells: Kidneys

Functions:
Increases reabsorption of sodium and water in the kidneys

Decreases excretion of potassium in the kidneys

Helps regulate blood volume and blood pressure

Aldosterone is a mineralocorticoid hormone produced by the adrenal cortex. It plays a key role in maintaining fluid and electrolyte balance in the body.

The secretion of aldosterone is controlled by the renin-angiotensin-aldosterone system. When blood volume or pressure drops, this system is activated, leading to increased aldosterone release.

Question 101

glucocorticoid (cortisol)

Answer 101

Name: Glucocorticoids (primarily Cortisol)

Source: Adrenal cortex (zona fasciculata)

Functions:
Regulate metabolism, helping to increase blood glucose levels

Suppress immune system function and inflammatory responses

Facilitate the body’s stress response

Influence growth, development, and behavior

Cortisol is the primary glucocorticoid hormone produced by the adrenal cortex. It has wide-ranging effects throughout the body, playing a crucial role in the body’s stress response.

Cortisol secretion is controlled by a negative feedback loop involving the hypothalamus, pituitary gland, and adrenal cortex. Stress triggers the release of cortisol to help the body cope.

Question 102

estrogen

Answer 102

Source: Ovaries

Target: Many body cells

Function: Regulates female reproductive function

Question 103

Testosterone

Answer 103

Source: Testes

Target: Many body cells

Function: Regulates male secondary sex characteristics and sperm production

Question 104

Epinephrine

Answer 104

Source: Adrenal Medulla

Target: Many body cells

Function: Fight or flight response

Increases Heart Rate: Epinephrine makes the heart beat faster and stronger, which boosts blood flow to muscles and vital organs.

Expands Airways: It relaxes the muscles around the airways in the lungs, allowing you to breathe easier and take in more oxygen.

Raises Blood Sugar Levels: Epinephrine triggers the release of glucose (sugar) from the liver, providing quick energy for muscles.

Boosts Blood Pressure: It constricts blood vessels, especially in areas like the skin, which raises blood pressure to ensure essential organs are well-supplied.

Enhances Alertness: It makes you more mentally alert and sharp, helping you respond quickly to danger or challenges.

Question 105

Norepinephrine

Answer 105

Source: Adrenal Medulla

Target: Many body cells

Function: Causes vasoconstriction in skin, viscera, and skeletal muscles

Question 106

progesterone

Answer 106

Source: Ovaries

Target: Many body cells

Function: Promotes the storage of glycogen and further growth of blood vessels in the endometrium, which in pregnancy becomes the placenta. Also helps maintain pregnancy.

Question 107

Androgens

Answer 107

Definition: A class of hormones that are important for male sexual development and function

Source: Primarily produced in the testes, but also in smaller amounts by the adrenal glands

Functions:

Regulate production of sperm

Stimulate development of male secondary sex characteristics (e.g. facial/body hair, deepening of voice)

Contribute to libido (sex drive)

Question 108

Inhibin

Answer 108

source: Testes and Ovaries

Target: Anterior Pituitary
Function: Inhibits secretion of Follicle-Stimulating Hormone (FSH)

Inhibin is a hormone produced by the gonads (testes in males, ovaries in females). Its main function is to provide negative feedback to the anterior pituitary gland, inhibiting the release of Follicle-Stimulating Hormone (FSH).

By reducing FSH levels, inhibin helps regulate sperm production in males and the menstrual cycle in females. This is an important part of the endocrine system’s feedback mechanisms to maintain hormonal balance.

Question 109

melatonin

Answer 109

Source: Pineal Gland

Target: Many body cells

Function: Helps regulate circadian rhythms and the sleep-wake cycle

Melatonin is a hormone produced by the pineal gland in the brain. Its main function is to help regulate the body’s internal clock and sleep-wake cycles. increases as it gets dark outside

Question 110

Prostaglandins

Answer 110

Source: Prostaglandins are produced from arachidonic acid in cell membranes throughout the body.

Target: Prostaglandins have local effects on the cells near where they are produced.

Functions: Prostaglandins regulate inflammation, blood flow, smooth muscle contraction, sleep-wake cycles, and kidney/electrolyte balance.

Question 111

Leukotrienes

Answer 111

Source: Leukotrienes are produced from arachidonic acid in activated immune cells, particularly white blood cells.

Target: Leukotrienes target nearby cells involved in the inflammatory response, such as other immune cells.

Functions: The main roles of leukotrienes are to promote inflammation, constrict smooth muscle, increase vascular permeability, and attract more immune cells to sites of inflammation.

Question 112

thymosin

Answer 112

Source: Thymosin is produced and released by the thymus gland, a lymphoid organ located in the upper chest.

Target: The target cells for thymosin are T lymphocytes, a type of white blood cell important for immune function.

Functions: The main roles of thymosin are to promote the production and maturation of T cells, enhance the activity of mature T cells, help the immune system fight infections and diseases, and potentially slow the aging process.

Question 113

Gastrin

Answer 113

Source: Gastrin is produced by G cells located in the lining of the stomach and duodenum (first part of the small intestine).

Target: The target cells for gastrin are the parietal cells in the stomach lining.

Functions: The main roles of gastrin are to stimulate the secretion of gastric acid by parietal cells, promote growth and development of the stomach lining, increase stomach motility, and help regulate the overall digestive process.

Question 114

GIP

Answer 114

Name: GIP stands for Glucose-Dependent Insulinotropic Peptide

Source: GIP is produced by K cells located in the duodenum and jejunum (parts of the small intestine)

Target: The target cells for GIP are the pancreatic beta cells

Function: The main role of GIP is to help regulate blood glucose levels by stimulating the release of insulin from pancreatic beta cells in response to the presence of glucose. GIP also slows gastric emptying to further control blood glucose.

Question 115

Secretin

Answer 115

Source: Secretin is produced by S cells located in the duodenum (first part of the small intestine)

Target: The target cells for secretin are the pancreatic acinar cells and cells lining the bile ducts and gallbladder

Functions: The main roles of secretin are to stimulate the pancreas to secrete bicarbonate-rich juice, stimulate the liver to secrete bile, help regulate the pH of the small intestine by neutralizing stomach acid, and slow the rate of gastric emptying to allow more time for digestion.

Question 116

CCK

Answer 116

Name: CCK stands for Cholecystokinin

Source: CCK is produced by I cells located in the duodenum and jejunum (first and second parts of the small intestine)

Target: The target cells for CCK include the gallbladder, pancreas, and stomach

Functions: The main roles of CCK are to stimulate the gallbladder to release stored bile, stimulate the pancreas to secrete digestive enzymes, slow the rate of gastric emptying to allow more time for digestion, and promote a feeling of fullness and satiety after eating.

Question 117

Erythropoietin (EPO)

Answer 117

Source: Erythropoietin (EPO) is produced by the kidneys.

Target: EPO travels through the bloodstream and targets the bone marrow.

Function: In the bone marrow, EPO stimulates the production of new red blood cells. This helps maintain normal oxygen levels in the body, as red blood cells are responsible for carrying oxygen.

Question 118

ANP

Answer 118

Atrial Natriuretic Peptide (ANP) is produced by the heart.

Target: ANP travels through the bloodstream and targets the kidneys.

Function: In the kidneys, ANP helps decrease blood pressure by increasing the excretion of sodium and water. This helps lower the overall volume of fluid in the body, reducing blood pressure.

Question 118

Leptin

Answer 118

Source: Leptin is produced by adipose (fat) tissue.

Target: Leptin travels through the bloodstream and targets the brain, specifically the hypothalamus.

Function: In the hypothalamus, leptin helps suppress appetite. Leptin may also increase the activity of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are important for regulating reproductive function.

Question 119

hCG

Answer 119

Name: Human chorionic gonadotropin (hCG)

Source: hCG is produced by the placenta during pregnancy.

Target: hCG travels through the bloodstream and targets the ovaries.

Function: In the ovaries, hCG stimulates the continued production of the hormones estrogen and progesterone. These hormones are crucial for maintaining the pregnancy.

Question 120

renin-angiotensin-aldosterone pathway (RAAS)

Answer 120

The RAAS pathway is an important hormonal system for regulating blood pressure and fluid balance in the body.

1. Decreased blood pressure or blood volume triggers the kidneys to release the enzyme renin.
2. Renin converts angiotensinogen (from the liver) into angiotensin I.
3. Angiotensin converting enzyme (ACE) in the lungs converts angiotensin I into angiotensin II.
4. Angiotensin II stimulates the adrenal cortex to release the hormone aldosterone.
5. Aldosterone acts on the kidneys to increase sodium and water reabsorption, raising blood pressure and fluid levels.

This pathway helps the body respond to low blood pressure or low blood volume by increasing fluid retention and blood pressure through the actions of renin, angiotensin, and aldosterone.

Question 121

the steps and stages of a stress response

Answer 121

The initial fight-or-flight response is triggered by the sympathetic nervous system and adrenal medulla. This quickly mobilizes the body’s resources for immediate physical activity, like fleeing from a threat.

The slower resistance reaction helps the body continue fighting the stressor long after the initial fight-or-flight response. This involves the hypothalamus-pituitary-adrenal axis.

The eventual exhaustion stage occurs if the resistance stage fails to combat the stressor. Prolonged exposure to high stress hormone levels can have negative health consequences.

Question 122

two main types of stress:

Answer 122

Physical stress - This threatens the survival of tissues, like extreme cold, prolonged exercise, or infections.

Psychological stress - This results from real or perceived dangers, including emotions like anger, depression, fear, and grief. Even pleasant stimuli can cause psychological stress.

Question 123

The body’s response to stress involves:

Answer 123

The body’s response to stress involves:

The hypothalamus controlling the general stress syndrome

Increased sympathetic activity and secretion of hormones like cortisol, glucagon, growth hormone, and antidiuretic hormone

These responses are designed to maintain homeostasis and help the body adapt to the stressor

Question 124

the effects of aging on the endocrine system

Answer 124

Production of many hormones, like growth hormone, thyroid hormones, and sex hormones, decreases with age.

Blood levels of other hormones, such as PTH, TSH, LH, and FSH, tend to increase with aging.

The pancreas releases insulin more slowly and cells become less sensitive to glucose as we get older.

The thymus gland shrinks in size after puberty and is replaced by fat and connective tissue.

Question 125

the olfactory process from the nose to the brain

Answer 125

The olfactory epithelium is located in the upper part of the nasal cavity. It contains olfactory receptor cells that have cilia (tiny hair-like projections) that stick out into the nasal cavity.

When you smell something, chemicals in the air stimulate the olfactory receptor cells. This creates an electrical signal.

The olfactory receptor cell axons (nerve fibers) extend through the cribriform plate of the ethmoid bone and form the olfactory (cranial nerve I) nerves.

The olfactory nerves carry the electrical signals to the olfactory bulbs at the base of the brain.

From the olfactory bulbs, the signals travel through the olfactory tract to the olfactory cortex in the temporal lobe of the brain, where the sense of smell is perceived and interpreted. 🧠

Question 126

what do the olfactory receptors in the olfactory epithelium (upper nasal cavity) do

Answer 126

These receptors detect different odor molecules in the air.

Question 127

The olfactory nerves (cranial nerve I)

Answer 127

These nerves carry the electrical signals from the olfactory receptors to the brain.

Question 128

The olfactory bulbs at the base of the brain

Answer 128

The olfactory nerves connect to the olfactory bulbs, where the signals are processed.

Question 129

olfactory glands

Answer 129

👃 The olfactory glands are located in the olfactory epithelium, which is the tissue that lines the upper part of the nasal cavity.

🧪 These glands secrete a thin layer of mucus over the olfactory receptors. This mucus helps to dissolve odor molecules so they can bind to the receptors.

💧 The olfactory glands also produce watery fluid that helps to keep the olfactory receptors moist and functioning properly.

🧠 The olfactory glands are important because they create the optimal environment for the olfactory receptors to detect and transmit smell information to the brain.

👨‍🔬 Without the olfactory glands, the olfactory receptors would dry out and not be able to do their job of sensing different smells.

Question 130

gustatory receptor cells

Answer 130

👅 The gustatory receptor cells are located in the taste buds on your tongue and other parts of your mouth.

🍔 When you eat food, the chemicals in that food dissolve in the saliva and come into contact with the gustatory receptor cells.

🧪 The receptor cells have specialized proteins on their surface that can bind to specific taste molecules, like sweet, sour, salty, bitter, and umami.

🧠 When the taste molecules bind to the receptors, it causes the gustatory receptor cells to generate electrical signals.

🧠 These electrical signals are then sent to the gustatory cortex in your brain, which allows you to perceive and identify different tastes.

👨‍🔬 The gustatory receptor cells are constantly being replaced, as they only live for about 10 days before being renewed.

Question 131

The olfactory epithelium contains 3 main types of cells:

Answer 131

Olfactory receptor cells - These are the cells that detect odors and send signals to the brain.

Supporting cells - These cells provide structure and support for the olfactory receptor cells.

Basal cells - These are stem cells that can replace the olfactory receptor cells when they die.

Question 132

what happens when looking at something close up

Answer 132

your eye lens changes shape, your pupils get smaller, and your eyes converge - all to help focus the image clearly on your retinas

Question 133

what happens when looking at something far away

Answer 133

when you look at something far away, your eye lens changes shape, your pupils get bigger, and your eyes diverge

Question 134

rhodopsin

Answer 134

Rods are very sensitive to light and allow you to see in dim lighting conditions, but only in shades of gray, not color.

Rhodopsin is the photopigment that allows rods to detect and respond to light.

When rhodopsin absorbs light, it undergoes a structural change that triggers a nerve impulse to be sent to your brain.

Rhodopsin is usually nonfunctional in bright daylight conditions. Your cones, which contain different photopigments, take over for color vision in bright light.

Question 135

two main parts of the inner ear

Answer 135

The outer bony labyrinth provides the structural framework and fluid-filled space for the inner membranous labyrinth.

The inner membranous labyrinth contains the specialized sensory receptors that detect sound waves and head/body movements for hearing and balance. 🧠👂

Question 136

otitis media

Answer 136

otitis media is a middle ear infection that can be common in young kids, but is treatable with the right medical care.

It occurs when the Eustachian tube, which connects the middle ear to the throat, becomes blocked or swollen

Question 137

Ménière’s disease

Answer 137

Ménière’s disease is a disorder that affects the inner ear and can cause debilitating episodes of vertigo, hearing problems, and a feeling of pressure or fullness in the affected ear

Question 138

barotrauma

Answer 138

Barotrauma refers to an injury caused by a difference in pressure between the inside and outside of the body.

When it comes to the ears, barotrauma can occur during activities like:

Flying in an airplane

Scuba diving

Going up or down in an elevator

Here’s what happens with ear barotrauma:

As the pressure changes, it can’t be equalized quickly enough between the middle ear and the outside environment.

This pressure difference causes the eardrum (tympanic membrane) to bulge inward or outward.

This can be painful and can even rupture the eardrum in severe cases.

Symptoms of ear barotrauma include:

Ear pain

Ringing in the ears

Hearing loss

Dizziness

Question 139

glaucoma

Answer 139

glaucoma is a serious eye condition caused by increased pressure inside the eye that can lead to vision loss if not properly managed.

Question 140

The pituitary gland

Answer 140

is a small, pea-sized endocrine gland located at the base of the brain. It’s often called the “master gland” because it produces hormones that regulate many important bodily functions.

Question 141

the pituitary glands tow main lobes

Answer 141

The anterior pituitary produces 7 major hormones, including:

Growth hormone (GH)

Thyroid-stimulating hormone (TSH)

Adrenocorticotropic hormone (ACTH)

The posterior pituitary stores and releases two hormones produced in the hypothalamus:

Oxytocin

Antidiuretic hormone (ADH)

Question 142

calcitriol

Answer 142

calcitriol is the active vitamin D hormone that regulates calcium and phosphate levels in the body

Increases the absorption of calcium and phosphate from the intestines 🍴

Increases the reabsorption of calcium in the kidneys 💦

Stimulates the release of calcium from the bones 🦴

Question 143

adrenal cortex

Answer 143

The adrenal cortex is the outer layer of the adrenal glands, which sit on top of the kidneys. 🏥

The adrenal cortex is divided into three main zones:

The outer zona glomerulosa - This zone secretes mineralocorticoids, like aldosterone, which help regulate sodium, water, and potassium balance in the body. 💧

The middle zona fasciculata - This zone secretes glucocorticoids, like cortisol, which help regulate metabolism, immune function, and the stress response. 🧠

The inner zona reticularis - This zone secretes androgens, which are male sex hormones that can be converted to estrogen in other tissues. 👨