Endocrine System

Which of the following best describes hormones?

A) Proteins that digest nutrients in the bloodstream
B) Neurotransmitters released at synaptic clefts
C) Signaling molecules secreted into the bloodstream to affect distant or nearby targets
D) Enzymes that act only on neighboring cells through the extracellular matrix

C) Signaling molecules secreted into the bloodstream to affect distant or nearby targets

How do hormones reach their target cells?

A) They are transported by nerve impulses
B) They diffuse only through local interstitial fluid
C) They travel through the bloodstream to both nearby and distant cells
D) They travel through lymphatic vessels to specific tissues

C) They travel through the bloodstream to both nearby and distant cells

Which body system is primarily responsible for secreting hormones?

A) Lymphatic system
B) Integumentary system
C) Endocrine system
D) Nervous system

C) Endocrine system

Which of the following distinguishes hormones from paracrine factors and neurotransmitters?

A) Hormones act only on adjacent cells
B) Hormones are secreted through ducts to the exterior
C) Hormones travel through the bloodstream, while paracrine factors and neurotransmitters act locally through extracellular fluid
D) Hormones and neurotransmitters are identical in both structure and function

C) Hormones travel through the bloodstream, while paracrine factors and neurotransmitters act locally through extracellular fluid

What is the primary function of the endocrine system?

A) Transport oxygen throughout the body
B) Secrete enzymes for digestion
C) Produce and release hormones to regulate body functions
D) Filter waste from the bloodstream

C) Produce and release hormones to regulate body functions

Define Endocrine System

glands, tissues, and cells that secrete hormones

What are endocrine glands?

organs that produce hormones

What are the classic endocrine glands

• Hypothalamus

• Pituitary gland

• Pineal gland

• Thyroid gland

• Parathyroid glands

• Thymus

• Adrenal gland

• Pancreas

• Gonads- Ovaries, Testes

Which of the following best describes the nervous system’s response to a stimulus?

A) It responds slowly over several hours
B) It responds in milliseconds and stops quickly
C) It acts only through hormone secretion
D) It causes long-lasting effects

B) It responds in milliseconds and stops quickly

Compared to the nervous system, how does the endocrine system typically respond to stimuli?

A) It responds faster than the nervous system
B) It acts immediately and then fades within seconds
C) It responds more slowly, often taking seconds to days
D) It only works during sleep

C) It responds more slowly, often taking seconds to days

Once the nervous system is no longer stimulated, how quickly do its effects typically cease?

A) They persist for days
B) They gradually decrease over several hours
C) They stop almost immediately
D) They increase in intensity over time

C) They stop almost immediately

Which characteristic is typical of endocrine signaling?

A) Rapid, short-term control
B) Continuous electrical impulses
C) Long-lasting effects even after hormone release stops
D) No effect without direct neuron contact

C) Long-lasting effects even after hormone release stops

How does the nervous system typically respond to long term stimulation?

A) It maintains a constant response over time
B) It gradually builds up a stronger response
C) It adapts quickly and may stop responding to the same stimulus
D) It has no ability to adapt

C) It adapts quickly and may stop responding to the same stimulus

How does the endocrine system respond to long-term stimulation?

A) It immediately shuts off hormone production
B) It rapidly changes hormone type
C) It adapts slowly, maintaining hormone release over time
D) It loses function with prolonged stimulation

C) It adapts slowly, maintaining hormone release over time

Which of the following correctly compares nervous and endocrine system adaptation to prolonged stimulation?

A) Both systems adapt quickly to maintain balance
B) The nervous system adapts slowly, while the endocrine system adapts quickly
C) The nervous system adapts quickly; the endocrine system adapts slowly
D) Neither system shows any adaptation

C) The nervous system adapts quickly; the endocrine system adapts slowly

What is a characteristic of the nervous system’s area of effect?

A) It affects all cells in the bloodstream equally
B) It has a broad and long-lasting effect
C) It is highly targeted, with specific neurons affecting specific cells
D) It releases hormones that travel through the body

C) It is highly targeted, with specific neurons affecting specific cells

For the nervous system to affect a cell, what must happen?

A) Hormones must bind to receptors in the blood
B) The neuron must send a hormone through the endocrine system
C) The neuron must directly connect to (innervate) the target cell
D) The neuron must activate a distant tissue through osmosis

C) The neuron must directly connect to (innervate) the target cell

Which of the following best describes the endocrine system’s area of effect?

A) All hormones act only on one cell type
B) Hormones travel short distances and require neuron contact
C) Hormones can have general or more specific targeted effects depending on the receptor distribution
D) Hormones must directly bind to nerves

C) Hormones can have general or more specific targeted effects depending on the receptor distribution

Which of the following is not a function of exocrine glands?

A) Delivering secretions to body surfaces or cavities
B) Producing effects in the extracellular environment
C) Direct hormonal communication between distant cells
D) Secreting substances like sweat and digestive enzymes

C) Direct hormonal communication between distant cells

How do exocrine glands release their products?

A) Directly into the bloodstream
B) Through ducts to epithelial surfaces or mucosa of digestive tract
C) Into the cerebrospinal fluid
D) By diffusing hormones across cell membranes

B) Through ducts to epithelial surfaces or mucosa of digestive tract

Where do ducts from exocrine glands typically deliver their secretions?

A) Only into the blood vessels
B) Into the lymphatic system
C) Onto an epithelial surface or into the mucosa of digestive mucosa
D) Into neuron synapses

C) Onto an epithelial surface or into the mucosa of digestive mucosa

What is a common feature of exocrine gland secretions?

A) They regulate gene expression inside cells
B) They act over long distances in the bloodstream
C) They produce extracellular effects, such as lubrication or digestion
D) They bind intracellular receptors in the nucleus

C) They produce extracellular effects, such as lubrication or digestion

Which of the following is an example of an exocrine secretion?

A) Insulin
B) Cortisol
C) Mucus
D) Thyroxine

C) Mucus

What are examples of secretion from exocrine glands

• Sweat

• Saliva

• Digestive Enzymes

• Mucus

Which of the following best describes the pancreas?

A) Only an endocrine organ
B) Only an exocrine organ
C) Both an endocrine and exocrine organ
D) A muscular and exocrine organ

C) Both an endocrine and exocrine organ

What is the primary function of the majority of pancreatic tissue?

A) Secreting insulin into the bloodstream
B) Producing melatonin
C) Releasing digestive enzymes into ducts
D) Filtering blood plasma

C) Releasing digestive enzymes into ducts

Which pancreatic structures are responsible for endocrine function?

A) Acinar cells
B) Islets of Langerhans
C) Duct cells
D) Alveoli

B) Islets of Langerhans

What is the primary role of endocrine glands?

A) Stimulating skeletal muscles
B) Facilitating nerve conduction
C) Communicating between cells by secreting hormones
D) Transporting oxygen to cells

C) Communicating between cells by secreting hormones

Hormones secreted by endocrine glands typically affect their target cells by:

A) Changing the cell’s DNA
B) Causing intracellular changes
C) Coating the cell membrane
D) Digesting extracellular matrix proteins

B) Causing intracellular changes

Which of the following distinguishes endocrine glands from exocrine glands?

A) They contain digestive enzymes
B) They use ducts to secrete their products
C) They release hormones directly into the bloodstream without ducts
D) They act only on the skin surface

C) They release hormones directly into the bloodstream without ducts

Why are endocrine glands richly supplied with capillaries?

A) To supply oxygen for digestion
B) To remove waste products
C) To allow direct hormone secretion into the blood
D) To cool glandular tissues

C) To allow direct hormone secretion into the blood

T/F: Endocrine glands are penetrated by capillaries

T

Which of the following best characterizes the endocrine system?

A) Fast and localized response using neurotransmitters
B) Non-communicative secretions into ducts
C) Slow and long-lasting intercellular communication via hormones in the bloodstream
D) Rapid enzyme secretion to mucosal surfaces

C) Slow and long-lasting intercellular communication via hormones in the bloodstream

What is a key feature of exocrine glands?

A) Secretion of neurotransmitters across synapses
B) Hormonal regulation of gene expression
C) Production of extracellular secretions delivered via ducts or to the digestive mucosa
D) Transmission of long-distance chemical signals through blood

C) Production of extracellular secretions delivered via ducts or to the digestive mucosa

Which of the following best describes how the nervous system communicates?

A) It slowly alters target cells over long durations using bloodstream signaling
B) It causes extracellular effects through enzymatic secretions
C) It quickly communicates between cells using neurotransmitters in synaptic clefts
D) It delivers hormones to mucosal surfaces via ducts

C) It quickly communicates between cells using neurotransmitters in synaptic clefts

Which system is correctly matched with its function?

A) Endocrine – Fast, duct-based chemical communication
B) Exocrine – Hormone-based intercellular signaling
C) Nervous – Fast, intercellular communication with short-lived effects
D) Endocrine – Secretes neurotransmitters into synapses

C) Nervous – Fast, intercellular communication with short-lived effects

Which of the following best describes hormone secretion?

A) Hormones are released continuously at the same rate throughout the day
B) Hormone secretion is random and unpredictable
C) Hormone synthesis and release vary depending on body needs and stimuli
D) Hormones are only secreted in response to stress

C) Hormone synthesis and release vary depending on body needs and stimuli

What term describes the natural, timed pattern of hormone secretion?

A) Reflex secretion
B) Rhythmic secretion
C) Random pulsation
D) Constant release

B) Rhythmic secretion

Which type of hormonal rhythm follows a 24-hour cycle and is influenced by light and dark?

A) Ultradian rhythm
B) Monthly rhythm
C) Circadian rhythm
D) Seasonal rhythm

C) Circadian rhythm

Which of the following is an example of a monthly hormone cycle?

A) Insulin release after a meal
B) Melatonin secretion at night
C) The female menstrual cycle
D) Epinephrine release in stress

C) The female menstrual cycle

Which of the following is an example of neural control of hormone secretion?

A) High blood glucose triggering insulin release
B) Hypothalamus releasing CRH to stimulate ACTH
C) Sympathetic stimulation of the adrenal medulla to release epinephrine
D) Rising calcium levels causing parathyroid hormone release

C) Sympathetic stimulation of the adrenal medulla to release epinephrine

Which of the following is an example of hormonal stimulation?

A) Insulin release in response to glucose
B) Sympathetic activation of the adrenal gland
C) Hypothalamic hormones stimulating the anterior pituitary
D) Parathyroid hormone responding to low calcium

C) Hypothalamic hormones stimulating the anterior pituitary

Which type of stimulus involves hormone release in response to changing levels of substances in the blood, such as glucose or calcium?

A) Neural stimulus
B) Hormonal stimulus
C) Humoral stimulus
D) Reflex stimulus

B) Hormonal stimulus

Which hormone is secreted in response to elevated blood glucose?

A) Glucagon
B) Cortisol
C) Insulin
D) Epinephrine

C) Insulin

How many major chemical classes of hormones exist in the human body?

A) Two
B) Three
C) Four
D) Five

B) Three

Which of the following hormone types is derived from cholesterol?

A) Peptides
B) Monoamines
C) Steroids
D) Glycoproteins

C) Steroids

Monoamine hormones are primarily derived from which type of building block?

A) Fatty acids
B) Nucleotides
c
D) Monosaccharides

C) single Amino acid

Peptide hormones are composed of:

A) A single fatty acid chain
B) Multiple amino acids linked together
C) Repeating sugar units
D) Sterol rings

B) Multiple amino acids linked together

Which of the following hormone types are hydrophilic and dissolve easily in blood plasma?

A) Steroid hormones
B) Peptide and monoamine hormones
C) Lipid hormones only
D) All hormones are hydrophobic

B) Peptide and monoamine hormones

How do monoamine and peptide hormones typically travel through the bloodstream?

A) Bound to carrier proteins
B) Inside red blood cells
C) Freely dissolved in blood plasma because they are hydrophilic
D) Through lymphatic vessels only

C) Freely dissolved in blood plasma because they are hydrophilic

Which hormone type is hydrophobic and does not dissolve easily in blood?

A) Peptides
B) Monoamines
C) Steroids
D) Glycoproteins

C) Steroids

Because they are hydrophobic, how do steroid hormones travel through the bloodstream?

A) Freely dissolved in plasma
B) Packaged in vesicles
C) Bound to transport proteins like albumin
D) Carried by red blood cells

C) Bound to transport proteins like albumin

How do hormones exert their effects on target cells?

A) By entering all cells and altering DNA directly
B) By binding to receptors on or inside specific target cells
C) By breaking down proteins in the bloodstream
D) By activating red blood cells to release enzymes

B) By binding to receptors on or inside specific target cells

What determines whether a hormone can affect a particular cell?

A) The distance from the hormone-secreting gland
B) The presence of transport proteins
C) The presence of a specific receptor for that hormone
D) The size of the cell

C) The presence of a specific receptor for that hormone

What is true about hormone-receptor binding?

A) One receptor can bind to many types of hormones
B) Each receptor usually binds only one specific hormone
C) All hormones bind to the same receptor
D) Receptors are not required for hormone action

B) Each receptor usually binds only one specific hormone

What contributes to a cell's sensitivity to a hormone?

A) Its size and shape
B) The number of mitochondria
C) The number of receptors for that hormone
D) The level of oxygen in the blood

C) The number of receptors for that hormone

What effect does increasing the number of hormone receptors on a target cell have?

A) It reduces hormone binding
B) It makes the cell immune to the hormone
C) It increases the cell’s sensitivity and response
D) It causes the hormone to degrade faster

C) It increases the cell’s sensitivity and response

What happens when a cell is exposed to high levels of a hormone for a long time?

A) It increases the number of receptors
B) It becomes more sensitive to the hormone
C) It expresses fewer receptors and becomes less sensitive
D) It stops producing enzymes

C) It expresses fewer receptors and becomes less sensitive

Where do peptide and monoamine hormones typically bind on target cells?

A) Mitochondria
B) Inside the nucleus
C) Cell membrane receptors
D) Ribosomes

C) Cell membrane receptors

Where do steroid hormones usually bind to exert their effects?

A) On the cell membrane
B) In the bloodstream
C) Inside the cell, often in the nucleus
D) In the digestive tract

C) Inside the cell, often in the nucleus

What is signal amplification in hormone action?

A) The release of multiple hormones from one gland
B) The breakdown of hormones in the liver
C) One hormone binding to a receptor activates many intracellular second messengers
D) A hormone being converted into glucose

C) One hormone binding to a receptor activates many intracellular second messengers

Why are hormones considered potent?

A) They have high atomic mass
B) They are produced in large quantities
C) Tiny amounts can produce large physiological effects
D) They can change into enzymes

C) Tiny amounts can produce large physiological effects

How do most peptide and monoamine hormones exert their effects?

A) By binding to intracellular receptors
B) By directly altering DNA
C) By activating second messengers after binding to membrane receptors
D) By entering mitochondria and altering energy production

C) By activating second messengers after binding to membrane receptors

Which of the following describes how steroid hormones act?

A) By activating second messengers
B) By dissolving in the cell membrane
C) Directly affect gene transcription- extremely powerful, don't need second messengers
D) By stimulating insulin release

C) Directly affect gene transcription- extremely powerful, don't need second messengers

Why can cells respond to different types of hormones?

A) They are exposed to only one hormone at a time
B) All cells have the same receptors
C) Most cells express receptors for multiple hormones
D) Hormones merge into a single signal

C) Most cells express receptors for multiple hormones

What is a synergistic effect of hormones?

A) One hormone reduces the effect of another
B) Two hormones act together to produce a greater effect than either alone
C) A hormone acts independently without needing receptors
D) Hormone action causes gene mutation

B) Two hormones act together to produce a greater effect than either alone

What is a permissive effect in hormone interaction?

A) A hormone inhibits another hormone
B) A hormone directly stimulates glucose breakdown
C) One hormone enhances a cell's response to another hormone
D) Two hormones cancel each other out

C) One hormone enhances a cell's response to another hormone

What is an antagonistic effect between hormones?

A) Two hormones stimulate the same pathway
B) One hormone prevents the action of another
C) A hormone increases the number of receptors
D) Hormones fuse to form one compound

B) One hormone prevents the action of another

Why must hormone effects eventually come to an end in the body?

A) Hormones become toxic if they remain too long
B) Hormone overproduction causes immune reactions
C) Continuous hormone action would disrupt homeostasis
D) Hormones only work during sleep

C) Continuous hormone action would disrupt homeostasis

Which two organs are primarily responsible for clearing hormones from the blood?

A) Heart and lungs
B) Liver and kidney
C) Brain and pancreas
D) Intestines and spleen

B) Liver and kidney

How does the liver help clear hormones from the body?

A) By filtering them into the lungs
B) By neutralizing them with hydrochloric acid
C) By breaking them down and excreting them into bile
D) By converting them into glycogen

C) By breaking them down and excreting them into bile

What is the kidney's role in hormone clearance?

A) It stores hormones for later use
B) It releases hormones into lymphatic fluid
C) It filters and excretes degraded hormones into urine
D) It converts hormones into glucose

C) It filters and excretes degraded hormones into urine

What does Metabolic Clearance Rate (MCR) measure?

A) How quickly a hormone is produced
B) How long a hormone binds to its receptor
C) The rate at which a hormone is removed from the blood
D) The number of receptors on a target cell

C) The rate at which a hormone is removed from the blood

What happens when a hormone has a high metabolic clearance rate (MCR)?

A) It remains active for a longer time
B) It is cleared from the blood more quickly
C) It accumulates in fat tissue
D) It travels slower through the bloodstream

B) It is cleared from the blood more quickly

T/F Lower MCR = hormone lingers longer and continues to influence cells.

T

What are the classic endocrine glands?

• Hypothalamus

• Pituitary gland

• Pineal gland

• Thyroid gland

• Parathyroid gland

• Thymus

• Adrenal gland

• Pancreas

• Gonads (Testes and ovaries)

Which description best fits the hypothalamus?

A) A flat cortical region in the brainstem
B) A funnel-shaped structure located inferior to thalamus
C) A large cerebellar lobe
D) A gland located in the adrenal cortex

B) A funnel-shaped structure located inferior to thalamus

Where is the hypothalamus located relative to the thalamus?

A) Superior
B) Posterior
C) Inferior
D) Lateral

C) Inferior

What role does the hypothalamus play in endocrine function?

A) It stores all hormones directly
B) It digests hormones from other glands
C) directs the pituitary gland and integrates nervous and endocrine responses
D) It functions only during sleep

C) directs the pituitary gland and integrates nervous and endocrine responses

What is another name for the pituitary gland?

A) Hippocampus
B) Infundibulum
C) Hypophysis
D) Thymus

C) Hypophysis

How is the pituitary gland connected to the hypothalamus?

A) By cranial nerves
B) Through the medulla
C) By the infundibulum, a stalk-like structure
D) By a duct system

C) By the infundibulum, a stalk-like structure

Why is the pituitary gland often called the “Master Gland”?

A) It stores calcium
B) It controls digestive enzymes
C) It controls many other endocrine glands
D) It filters toxins

C) It controls many other endocrine glands

What are the two major divisions of the pituitary gland?

A) Cortex and medulla
B) Superior and inferior lobes
C) Anterior pituitary and posterior pituitary
D) Exocrine and endocrine pituitary

C) Anterior pituitary and posterior pituitary

What is another name for the anterior pituitary?

A) Neurohypophysis
B) Hippocampus
C) Adenohypophysis
D) Epithalamus

C) Adenohypophysis

Approximately what fraction of the total pituitary gland is made up by the anterior pituitary?

A) ¼
B) ½
C) ¾
D) All

C) ¾

What type of tissue makes up the anterior pituitary?

A) Nervous tissue
B) Cartilage
C) Connective tissue
D) Glandular (epithelial) tissue

D) Glandular (epithelial) tissue

How does the anterior pituitary receive regulatory signals from the hypothalamus?

A) Through direct neural connections
B) Via the lymphatic system
C) Through the hypophyseal portal system (network of blood vessels)
D) Through cerebrospinal fluid

C) Through the hypophyseal portal system (network of blood vessels)

How do hormones from the hypothalamus reach the anterior pituitary to regulate its function?

A) Through axons of neurons
B) By diffusion through surrounding tissue
C) Via the hypophyseal portal blood vessels
D) Through ducts in the infundibulum

C) Via the hypophyseal portal blood vessels

What is another name for the posterior pituitary?

A) Adenohypophysis
B) Hypothalamus
C) Neurohypophysis
D) Thalamus

C) Neurohypophysis

What proportion of the total pituitary gland is made up by the posterior pituitary?

A) ½
B) ¼
C) ¾
D) All

B) ¼

What type of tissue makes up the posterior pituitary?

A) Glandular epithelium
B) Connective tissue
C) Nervous tissue
D) Cartilage

C) Nervous tissue

How are hormones delivered to and released from the posterior pituitary?

A) Via portal blood vessels from the hypothalamus
B) By exocytosis through ducts
C) Through axon tracts that travel from hypothalamus neurons to post pit., which release hormones into the bloodstream
D) From capillaries in the adrenal gland

C) Through axon tracts that travel from hypothalamus neurons to post pit., which release hormones into the bloodstream

What hormones are released from the Anterior Pituitary gland?

• Gonadotropin Hormones (FSH, LH)

• TSH

• ACTH

• PRL

• GH

Which of the following hormones are classified as gonadotropins?

A) TSH and ACTH
B) FSH and LH
C) ADH and oxytocin
D) Prolactin and insulin

B) FSH and LH

What is the primary target tissue of gonadotropin hormones?

A) Thyroid gland
B) Adrenal cortex
C) Gonads (ovaries and testes)
D) Liver

C) Gonads (ovaries and testes)

Why are gonadotropins named based on their effects on female gonads?

A) They were first studied in males
B) Their primary role is sperm production
C) named for the effects on the ovarian cycle
D) They do not affect male gonads

C) named for the effects on the ovarian cycle

In females, what is a primary role of FSH (follicle-stimulating hormone)?

A) Stimulating ovulation
B) Producing estrogen in the adrenal cortex
C) Stimulating ovarian follicle development
D) Increasing progesterone in the hypothalamus

C) Stimulating ovarian follicle development

What role does FSH play in the male reproductive system?

A) Stimulates testosterone secretion
B) Inhibits sperm production
C) Stimulates sperm production in the testes
D) Promotes egg development

C) Stimulates sperm production in the testes

Which of the following is a function of LH (luteinizing hormone) in females?

A) Inhibits follicle growth
B) Stimulates ovulation and corpus luteum formation
C) Promotes milk production
D) Enhances estrogen breakdown

B) Stimulates ovulation and corpus luteum formation

In males, what is the role of LH?

A) Inhibits sperm motility
B) Stimulates production of estrogen
C) Stimulates testosterone secretion from the testes
D) Promotes follicle formation

C) Stimulates testosterone secretion from the testes