Lecture Review – Nervous, Endocrine, Blood, Cardiovascular & Immunity

Question-and-Answer flashcards covering neuroglia, nervous signaling, autonomic functions, endocrine concepts, blood composition, cardiovascular anatomy, immunity, and related clinical correlations from the lecture transcript.

Which neuroglial cell is the most abundant and helps form the blood-brain barrier?

The astrocyte.

What neuroglial cells line brain ventricles and produce cerebrospinal fluid (CSF)?

Ependymal cells.

Which neuroglial cells make the myelin sheath in the central nervous system and are targeted in multiple sclerosis?

Oligodendrocytes.

Name the phagocytic "macrophages of the brain."

Microglial cells.

Which cells myelinate axons in the peripheral nervous system?

Schwann cells.

How many pairs of spinal nerves are there?

31 pairs.

How many pairs of cranial nerves exist, and which is number 10?

12 pairs; cranial nerve 10 is the vagus nerve.

Define afferent neurons.

Neurons that carry information toward the CNS.

Define efferent neurons.

Neurons that carry information away from the CNS to effectors.

Give two common types of effectors for efferent neurons.

Muscles and glands (including smooth muscle, cardiac muscle, and glands).

In the CNS, what color matter contains myelinated axons that conduct impulses rapidly?

White matter.

Where do most synapses occur in the spinal cord?

Gray matter.

What vitamin deficiency is strongly linked to spina bifida?

Folic acid (a B-vitamin) deficiency.

Which branch of the autonomic nervous system is nicknamed "fight or flight"?

The sympathetic nervous system.

Which branch of the autonomic nervous system is nicknamed "rest and digest"?

The parasympathetic nervous system.

During an excitatory postsynaptic potential, which ion channels typically open?

Sodium (Na⁺) channels.

Opening of which ion channels usually produces an inhibitory postsynaptic potential?

Chloride (Cl⁻) channels.

What makes a cell a target for a particular hormone?

Possession of the specific receptor for that hormone.

How do endocrine glands release their secretions?

Directly into the bloodstream.

What is paracrine signaling?

Local chemical communication between neighboring cells without entering the blood.

Define an exocrine gland.

A gland that releases its product into a duct that ultimately exits the body (e.g., pancreatic digestive enzymes).

Why can steroid hormones cross the plasma membrane freely?

They are hydrophobic lipids and dissolve in the membrane’s lipid bilayer.

Where are receptors for steroid hormones generally located?

Inside the target cell (often in the cytoplasm or nucleus).

Why do non-steroid (peptide) hormones need a second messenger?

They are hydrophilic and cannot cross the cell membrane, so their surface receptor activates an intracellular second-messenger system (e.g., cAMP).

List five major steroid hormones mentioned in class.

Estrogen, testosterone, progesterone, aldosterone, and cortisol (vitamin D is steroid-like).

Which component forms a little over 50 % of whole blood volume?

Plasma.

Name two broad cellular components of blood.

Red blood cells (erythrocytes) and white blood cells (leukocytes).

What kidney-secreted hormone stimulates erythrocyte production in bone marrow during hypoxia?

Erythropoietin (EPO).

Which formed element is primarily responsible for blood clotting?

Platelets (thrombocytes).

Which plasma protein, produced by the liver, is the most abundant and important for osmotic pressure?

Albumin.

Which leukocyte type rises with bacterial infection and is the body’s main bacteria killer?

Neutrophils.

Which leukocyte combats parasitic worms and mediates allergic responses?

Eosinophils.

What do monocytes become after leaving the bloodstream?

Macrophages.

Which leukocytes provide adaptive immunity featuring specificity and memory?

Lymphocytes (B and T cells).

Define thrombus.

A stationary blood clot attached to a vessel wall.

Define embolus.

A clot or fragment that breaks free and travels in the bloodstream.

Trace the normal pathway of blood flow starting at the venae cavae.

Venae cavae → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary artery → lungs → pulmonary veins → left atrium → bicuspid (mitral) valve → left ventricle → aortic valve → aorta.

Which vessels carry oxygenated blood from lungs to the heart?

Pulmonary veins.

What single cell layer lines all blood vessels and heart chambers?

Endothelium (endothelial cells).

How many oxygen molecules can one hemoglobin carry?

Four oxygen molecules.

Where are old red blood cells primarily removed from the circulation?

The spleen.

Which pigment derived from heme breakdown is processed by the liver to form bile?

Bilirubin.

What anemia results from vitamin B₁₂ malabsorption due to lack of intrinsic factor?

Pernicious anemia.

Intrinsic factor is produced by which organ?

The stomach.

Which blood type lacks both A and B antigens on erythrocytes?

Type O blood.

Why is Rh incompatibility a concern when an Rh-negative mother carries an Rh-positive fetus?

The mother can produce anti-D antibodies that attack fetal red blood cells.

What metabolic cycle in the liver converts toxic amino groups to urea?

The urea cycle.

Why should patients with kidney failure limit excessive dietary protein?

Protein catabolism generates urea and other nitrogenous wastes that diseased kidneys cannot adequately excrete.

Which B-vitamin deficiency is associated with spina bifida during fetal development?

Folic acid deficiency.