Artlabeling Activity Internal Anatomy of the Heart 2 of 2 Quizlet

Learning Objectives

By the end of this section, you will be able to:

• Draw the external construction of the kidney, including its location, support structures, and covering
• Identify the major internal divisions and structures of the kidney
• Identify the major blood vessels associated with the kidney and trace the path of claret through the kidney
• Compare and contrast the cortical and juxtamedullary nephrons
• Proper noun structures found in the cortex and medulla
• Describe the physiological characteristics of the cortex and medulla

The kidneys lie on either side of the spine in the retroperitoneal space between the parietal peritoneum and the posterior abdominal wall, well protected by muscle, fat, and ribs. They are roughly the size of your fist, and the male kidney is typically a flake larger than the female person kidney. The kidneys are well vascularized, receiving about 25 percent of the cardiac output at balance.

Interactive Link

In that location have never been sufficient kidney donations to provide a kidney to each person needing i. Sentry this video to learn about the TED (Technology, Entertainment, Pattern) Conference held in March 2011. In this video, Dr. Anthony Atala discusses a cut-edge technique in which a new kidney is "printed." The successful utilization of this engineering science is nonetheless several years in the futurity, just imagine a time when you can print a replacement organ or tissue on demand.

External Anatomy

The left kidney is located at about the T12 to L3 vertebrae, whereas the right is lower due to slight displacement past the liver. Upper portions of the kidneys are somewhat protected past the eleventh and twelfth ribs (Figure 25.7). Each kidney weighs most 125–175 g in males and 115–155 k in females. They are near 11–14 cm in length, 6 cm broad, and 4 cm thick, and are directly covered past a gristly capsule composed of dense, irregular connective tissue that helps to hold their shape and protect them. This sheathing is covered past a shock-absorbing layer of adipose tissue called the renal fat pad, which in turn is encompassed by a tough renal fascia. The fascia and, to a lesser extent, the overlying peritoneum serve to firmly anchor the kidneys to the posterior abdominal wall in a retroperitoneal position.

Effigy 25.vii Kidneys The kidneys are slightly protected past the ribs and are surrounded by fat for protection (not shown).

On the superior attribute of each kidney is the adrenal gland. The adrenal cortex directly influences renal function through the production of the hormone aldosterone to stimulate sodium reabsorption.

Internal Anatomy

A frontal section through the kidney reveals an outer region chosen the renal cortex and an inner region chosen the medulla (Figure 25.8). The renal columns are connective tissue extensions that radiate downward from the cortex through the medulla to separate the most characteristic features of the medulla, the renal pyramids and renal papillae. The papillae are bundles of collecting ducts that transport urine made by nephrons to the calyces of the kidney for excretion. The renal columns besides serve to divide the kidney into 6–8 lobes and provide a supportive framework for vessels that enter and go out the cortex. The pyramids and renal columns taken together constitute the kidney lobes.

Figure 25.8 Left Kidney

Renal Hilum

The renal hilum is the entry and exit site for structures servicing the kidneys: vessels, nerves, lymphatics, and ureters. The medial-facing hila are tucked into the sweeping convex outline of the cortex. Emerging from the hilum is the renal pelvis, which is formed from the major and minor calyxes in the kidney. The smoothen muscle in the renal pelvis funnels urine via peristalsis into the ureter. The renal arteries grade directly from the descending aorta, whereas the renal veins render cleansed claret directly to the inferior vena cava. The avenue, vein, and renal pelvis are arranged in an anterior-to-posterior social club.

Nephrons and Vessels

The renal artery first divides into segmental arteries, followed by further branching to form interlobar arteries that pass through the renal columns to reach the cortex (Effigy 25.9). The interlobar arteries, in plow, branch into arcuate arteries, cortical radiate arteries, so into afferent arterioles. The afferent arterioles service most i.3 million nephrons in each kidney.

Figure 25.9 Blood Flow in the Kidney

Nephrons are the "functional units" of the kidney; they cleanse the blood and residual the constituents of the circulation. The afferent arterioles class a tuft of high-pressure capillaries about 200 µm in diameter, the glomerulus. The rest of the nephron consists of a continuous sophisticated tubule whose proximal end surrounds the glomerulus in an intimate encompass—this is Bowman'due south capsule. The glomerulus and Bowman's sheathing together form the renal corpuscle. As mentioned before, these glomerular capillaries filter the blood based on particle size. After passing through the renal corpuscle, the capillaries form a second arteriole, the efferent arteriole (Effigy 25.10). These will next form a capillary network around the more distal portions of the nephron tubule, the peritubular capillaries and vasa recta, earlier returning to the venous system. Equally the glomerular filtrate progresses through the nephron, these capillary networks recover most of the solutes and water, and render them to the circulation. Since a capillary bed (the glomerulus) drains into a vessel that in turn forms a second capillary bed, the definition of a portal system is met. This is the only portal system in which an arteriole is found betwixt the beginning and 2nd capillary beds. (Portal systems also link the hypothalamus to the inductive pituitary, and the blood vessels of the digestive viscera to the liver.)

Figure 25.10 Blood Flow in the Nephron The ii capillary beds are clearly shown in this figure. The efferent arteriole is the connecting vessel between the glomerulus and the peritubular capillaries and vasa recta.

Interactive Link

Visit this link to view an interactive tutorial of the flow of blood through the kidney.

Cortex

In a dissected kidney, information technology is easy to identify the cortex; it appears lighter in colour compared to the rest of the kidney. All of the renal corpuscles as well as both the proximal convoluted tubules (PCTs) and distal convoluted tubules are found here. Some nephrons have a brusque loop of Henle that does not dip across the cortex. These nephrons are called cortical nephrons. Almost 15 percent of nephrons have long loops of Henle that extend deep into the medulla and are called juxtamedullary nephrons.

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Source: https://openstax.org/books/anatomy-and-physiology-2e/pages/25-3-gross-anatomy-of-the-kidney

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