Nerve Division and Autonomic Nervous System

Flashcards covering key concepts about the Nervous System, Endocrine System, and Blood Functions for exam preparation.

What does the Somatic Division of the PNS innervate?

Skeletal muscle (effectors).

What neurotransmitter is always used in the Somatic Division?

ACh (acetylcholine).

What type of neuron chain is found in the Autonomic Division?

A two-neuron chain consisting of a preganglionic neuron and a postganglionic neuron.

In the Autonomic Division, what neurotransmitters are used?

ACh or NE (norepinephrine).

What is the general role of the Sympathetic Nervous System?

'Fight or Flight' response.

What is the general role of the Parasympathetic Nervous System?

'Rest and Digest' response.

How do the preganglionic fibers differ between the Sympathetic and Parasympathetic functions?

Sympathetic preganglionic fibers are short and release ACh, while Parasympathetic fibers are long and also release ACh.

What happens to heart rate during the Sympathetic response?

It increases.

What happens to heart rate during the Parasympathetic response?

It decreases.

What type of receptors are primarily involved in the Sympathetic response?

Adrenergic receptors (α, β) for NE.

What type of receptors are primarily involved in the Parasympathetic response?

Cholinergic (muscarinic) receptors for ACh.

What type of receptors detect stretch/pressure?

Mechanoreceptors.

What receptors respond to light?

Photoreceptors.

What are Chemoreceptors responsible for?

Detecting chemical changes (taste, smell, blood chemistry).

What is the role of Nociceptors?

Detecting pain from tissue-damaging stimuli.

Where are Exteroceptors located?

Near body surface (e.g., skin).

Where are Interoceptors located?

In visceral organs and blood vessels.

Where are Proprioceptors located?

In muscles, tendons, and joints for sensing body position/movement.

What is the key process for sensory receptors transforming stimuli?

Transduction.

What is the mechanism of action for Muscle Spindles?

They detect muscle stretch and initiate contraction to resist stretch.

What do Tendon Organs detect?

Muscle tension (pull on the tendon).

What is the response mechanism of Tendon Organs when activated?

Inhibition of α-motor neurons to relax the muscle.

What are the five key components of a spinal reflex arc?

Receptor, sensory neuron, integration center, motor neuron, effector.

What does the Stretch Reflex involve?

Muscle spindle detection leading to muscle contraction.

What initiates the Withdrawal (Flexor) Reflex?

A painful stimulus.

What characterizes the Crossed-Extensor Reflex?

Contralateral side extends while ipsilateral side flexes.

What are the two main types of glands in the endocrine system?

Exocrine and Endocrine glands.

How do exocrine glands function?

They have ducts that secrete their products (e.g., sweat, salivary glands).

What is a characteristic feature of endocrine glands?

They are ductless and secrete hormones directly into the bloodstream.

What kind of stimuli can lead to hormone release?

Humoral, Neural, and Hormonal stimuli.

What is the mechanism of action for water-soluble hormones?

They bind surface receptors and initiate a signaling cascade via second messengers.

What is the mechanism of action for lipid-soluble hormones?

They diffuse through the plasma membrane, bind intracellular receptors and initiate gene transcription.

What is the role of ADH (Antidiuretic Hormone)?

To increase water reabsorption in the kidneys.

What is the main function of Insulin?

To lower blood glucose levels.

What is the main function of Glucagon?

To raise blood glucose levels.

What stimulates the secretion of Cortisol?

CRH from the hypothalamus stimulates ACTH release from the anterior pituitary.

What is the role of Aldosterone?

To regulate sodium and potassium balance, influencing blood pressure.

What initiates the Renin-Angiotensin-Aldosterone System?

Low blood pressure or low sodium levels.

What hormones are synthesized in the posterior pituitary?

Oxytocin and Antidiuretic Hormone (ADH).

What is the primary role of Oxytocin?

To facilitate uterine contractions and milk ejection.

Which hormones are secreted by the anterior pituitary?

TSH, ACTH, FSH, LH, GH, and PRL.

What does GH stimulate?

Growth of bones and muscles as well as metabolism.

What does the blood plasma primarily consist of?

Water, proteins (such as albumin), nutrients, wastes, and hormones.

What is erythropoiesis?

The formation of red blood cells (RBCs).

What triggers the release of EPO (erythropoietin)?

Low oxygen levels (hypoxia).

What is the average lifespan of a red blood cell?

Approximately 120 days.

What do elevated or lowered WBC counts indicate?

Possible infections or allergies.

What are the steps of hemostasis?

Vascular spasm, platelet plug formation, and coagulation.

What is the role of fibrin in clotting?

To form a mesh that traps RBCs and platelets, creating a stable clot.

What is the function of plamin in fibrinolysis?

To digest the fibrin mesh once healing is complete.

What determines blood type in the ABO system?

The presence or absence of A and B antigens on the RBC surface.

What blood group is considered the universal donor?

Type O blood.

What blood group is considered the universal recipient?

Type AB blood.

What occurs during a mismatch reaction in blood transfusion?

Agglutination and possible hemolysis of donor RBCs.

What is a complete blood count (CBC)?

A test that measures RBC count, WBC count, platelets, and hemoglobin.

What does the hematocrit test detect?

The percentage of RBCs in blood; used to identify anemia or polycythemia.

How do antibodies function in blood typing?

They react against specific antigens present on RBCs.

What role do neurotransmitters play in the autonomic nervous system?

They facilitate communication between neurons and target organs.

What does reciprocal inhibition in reflex arcs ensure?

That antagonist muscles relax while the agonist muscles contract.

Which type of endocrine gland secretes insulin?

The pancreas.

What type of hormones are steroids classified as?

Lipid-soluble hormones.

What is the primary effect of cortisol in the body?

To regulate metabolism and manage stress responses.

What is the effect of sympathetic stimulation on blood vessels?

It generally causes vasoconstriction.

What actions would the parasympathetic division promote?

Digestive processes and energy conservation.

What kind of effect does ACh have on heart rate in the parasympathetic system?

It decreases heart rate.

What metabolic process does glucagon promote in the liver?

Glycogenolysis and gluconeogenesis.

What happens during muscle spindle activation?

Muscle contraction to resist being stretched.

What is indicated by a complete blood cell count showing elevated neutrophils?

An ongoing infection.

What are the consequences of clotting factor disorders?

Increased bleeding risk.

Which organ is primarily responsible for recycling old red blood cells?

The spleen.

What role do muscle spindles play in proprioception?

They sense changes in muscle length.

What is the significance of a negative feedback loop in hormone regulation?

It helps to maintain homeostasis by regulating hormone levels.

What component of blood is primarily responsible for transport?

Red blood cells (erythrocytes).

How does the body respond to increased blood osmolarity?

By secreting ADH to promote water retention.

What is the primary component of platelet plugs in hemostasis?

Aggregated platelets adhering to collagen.

Which part of the blood is involved in immune defense?

Leukocytes (white blood cells).

What triggers the coagulation cascade?

Intrinsic or extrinsic pathways activating clotting factors.

What is the role of albumin in blood?

To maintain osmotic pressure and transport substances.

What is a common cause of blood type incompatibility in transfusions?

Presence of donor RBC antigens that the recipient’s antibodies react against.

What is essential for the synthesis of all steroid hormones?

Cholesterol.

How do steroids exert their effects on target cells?

By binding to intracellular receptors and influencing gene expression.

What physiological changes are associated with cortisol release during stress?

Increased glucose levels and energy mobilization.